IRON 
 FOUNDING 
 
 WYLIE 
 
 5/e 
 
FRflnKLIH [HSTiTgrc LiBRflRT. 
 
 Tnstitute, or by members or iioiaers oi secouu ciass istuuis., wuo xi« *v. v^,^ 
 tained the sanction of the Committee. The second class shall include 
 those books intended for circulation. 
 
 Article VI. — The Secretary shall have authority to loan to members 
 and to holders of second class stock, any work belonging to the second 
 CLASS, subject to the following regulations. ' 
 
 Section 1. — No individual shall be permitted to have more than two 
 hooks out at one time, without a written permission, signed by at least 
 two members of the Library Committee , nor shall a book be kept mit 
 more than TM-o weeks; but if no one has applied for it, the former bor- 
 rower may renew the loan. Should any person have applied for it, the 
 latter shall have the preference. 
 
 Section 2. — A fine of ten cents per week shall be exacted for the 
 detention of a book beyond the limited time; and if a book be not re- 
 turned within three months it shall be deemed lost, and the borrower 
 shall, in addition to his fines, forfeit its value. 
 
 Section 3. — Should any book be returned injured, the borrower shall 
 pay for the injur}^, or replace the book, as the Library Committee may 
 direct; and if one or more books, belonging to a set or sets, be lost, the 
 borrower shall replace them or make full restitution. 
 
 Article VII. — Any person removing from the hall, without permis- 
 sion from the proper authorities, any book, newspaper or other x)ropeT"ty 
 in charge of the Library Committee, shall be reported to the Committee, 
 who ma}' inflict any fine not exceeding twenty-five dollars. 
 
 Article VIII. — No member or holder of second class stock, whose 
 annual contribution for the current year shall be unpaid or who is in 
 arrears for fines, shall be entitled to tlie privileges of the Library or 
 Reading Room. 
 
 Article IX. — If an}^ member or holder of second class stock, shall 
 refuse or neglect to comply with the foregoing rules, it shall be the duty 
 of the Secretary to report him to the Committee on the Librar3^ 
 
 Article X. — Any member or holder of second class stock, detected 
 in mutilating the newspapers, pamphlets or books belonging to the Insti- 
 tute shall be deprived of his right of membership, and the name of the 
 offender shall be made public. 
 
lEON FOUNDING. 
 
AMERICAN EDITION 
 
 A TEEATI8E 
 
 ON 
 
 IRON FOUNDING 
 
 BY 
 
 CLAUDE WYIjV^ '^^i 
 
 TRACTICAL IRON MOULDER 
 
 SUNDERLAND 
 
 ILLUSTEATED WITH DIAGEAMS 
 
 ^f' SUNDEELAND 
 PUBLISHED BY AND FOE THOMAS EEED & CO 
 184, High Street West 
 
 london : simpkix, maeshall, and co. ; hamilton, apams, 
 and co. ; and e. and f. n. spon 
 
C4>A(S 
 
PEEFACE. 
 
 This volume, although hastily prepared and consequently 
 in many ways imperfect, the Author is induced to publish 
 on account of the importance of the subject, and because 
 much new ground — and that not a moment too soon — ^has 
 been touched upon for the first time. 
 
 Whilst this treatise is intended for the whole of the Engi- 
 neering profession, it is more especially and confidently 
 tendered to Moulders, who, the Author feels sure, will not 
 fail to appreciate any merit it ma}^ possess ; but he begs of 
 all parties to be lenient in regard to its blemishes. 
 
 To keep the price of the book down, and so place it within 
 the reach of all, the use of diagrams has been avoided as- 
 far as possible ; still it will be found that illustrations have 
 been supplied in all cases where they were really necessary. 
 
 Rules for finding the weight of cast-iron in various forms- 
 have been introduced, and will be found very useful. 
 
 The author thankfully acknowledges the quotations he has. 
 given from the following v^aluable works, viz. — Dr. Percy's 
 Metallurgy ; Tomlinson's Encyclopa3dia of useful Arts ; the 
 British Cyclopsedia ; the Cabinet Cyclopaedia ; Bloxham on 
 Metals, their Properties and Treatment ; and Spretson on 
 Casting and Founding. 
 
EEEATA. 
 
 Page 31, line 13. For blow," read below." 
 
 Page 100, line 3. For Sand Moulding," read ^^ron 
 Sand Moulding." 
 
 Plate Moulding" begins at page 75, and not at 
 page 77. 
 
CON 
 
 Castings in Primitive Times ^, ' . .^^:^SV . . . . o 
 
 Core Sand .. .. ^'-^ . I'fi .. 10 
 
 Green Sand . . . . . . . . . . 11 
 
 Dry Sand .. .. .. .. .. 13 
 
 Loam . . . . . . . . . . . . 13 
 
 Core Making . . . . . . . . 17 
 
 Venting Cores and Moulds . . , . . . 22 
 
 Scabs and Scales — their Cause and Effect . . 32 
 
 Scales . . . . . . . . . . . . 38 
 
 Cold Shot Castings . . . . . . . . 40 
 
 Mending or Burning Castings . . . . . . 41 
 
 Eamming Green or Dry Sand . . . . . . 45 
 
 Hints on Patterns . . . . . . . . 48 
 
 Punning Metal into Moulds, and the use of Flo'ers or 
 
 Gates . . . . . . . . 50 
 
 The Mould filled too slowly . . . . . . 58 
 
 too quickly . . . . . . 62 
 
 The use of Flow- gates , . . . . . . . 65 
 
 Light Green Sand Casting . . . . . . 72 
 
 Work . . . . . . . . 74 
 
 Plate Moulding . . . . . . . . 75 
 
 Heavy Castings in Green Sand and Dry Sand . . 84 
 
 Bad Lifts with the Toi) Part . . • . . . 94 
 
 Dry Sand Moulding . . . . . . . . 96 
 
 Loam Moulding . . . . , . . . 98 
 
 Irregular Building of a Mould . . . . . . 105 
 
 Finishing the Mould . . .. .. .. 107 
 
 Castings Pent or Sprung .. .. .. ..109 
 
 Closing the Mould . . . . . . . . 112 
 
 Eamming Loam Moulds with Sand . . .. 114 
 
Contents. — Continued. 
 
 Making tlie Heads .. .. .. IIB 
 
 The Composition of Cast Iron . . . . . . 119 
 
 Mixtures of Cast Iron for Castings .... 128 
 
 The Cupola and Air Furnace .. .. ..129 
 
 Cupolas .. .. 130 
 
 "Charging the Cupola . . . . . . . . 135 
 
 Fans or Blowers .. .. .. 136 
 
 Gathering Metal for Large Castings . . . . 139 
 
 Metal Gathered in one Ladle . . . . . . 141 
 
 Air Furnace . . . . . . . . . . 143 
 
 Chilled Castings . . . . . . . . 145 
 
 Malleable Cast Iron . . . . . . . . 147 
 
 Chaplets and their use . . . . . . ,149 
 
 Shop Management . . . . . . . . 154 
 
 The Formation of a Foundry .. .. 156 
 
 Weights of Castings . . . , . . . . 157 
 
 Cubical Contents of Eound Plates . . . . 159 
 
 yy Cylindrical Bodies .. .. 159 
 
 Strength of Eopes . . . . . . . . 161 
 
 Chains . . . . . . . . 161 
 
 General Eemarks . . . . . , . . 163 
 
 DIAGEAMS. 
 
 Snugs and Flange . . . . . . . . . . 24 
 
 Scabs . . ' ' . . . . . . . . 33 
 
 Wide Joints next the Mould . . . . . . 36 
 
 Dumb Scabs on a Propeller . . . . . . 37 
 
 Cold-Shot Castings. . .. .. 40,60- 
 
A TREATISE ON IRO^^ FOUNDING. 
 
 CASTINGS IN PEIMITIVE TIMES. 
 
 IT seems to be generally admitted that Tubal Cain ^as 
 the inventor of the foundry. There are some Tvho say — 
 Not so : Geology tells us that castings in bronze were made 
 long before Tubal Cain. Be that as it may, it is not our 
 province to question such assertions ; but we can safely say 
 that the evidence of bronze castings before the days of 
 Tubal are not very plentiful, and the evidence in many cases 
 must be pure conjecture. We can only go by what records 
 we have ; and we find that Tubal Cain, the son of Lamech, 
 is recorded as being the inventor of casting, and, it is 
 believed, the ''Vulcan," or god of blacksmiths, of the heathen, 
 (Gen. iv. 22), his brother Jubal being the inventor of Music. 
 
 We have no record of what Tubal did in casting or forging ; 
 all that we know is, that he could do both, and that he was 
 the first we know of who could do so ; therefore we will leave 
 him, and find the next man skilled in brass and iron working. 
 . We find in 1 Kings, vii. 13, that Solomon sent and 
 fetched Hiram, a widow's son, out of Tyre, and as his 
 father had been, '' filled with wisdom, understanding, and 
 cunning, to work all works in brass." His first work 
 seems to have been to cast two pillars in brass. Now, the 
 huge size of these pillars in height and diameter is amazing, 
 
 B 
 
6 
 
 A TREATISE ON 
 
 and their weight must have been enormous, especially if 
 there was no core in the casting. No doubt Hiram was 
 cunning, or rather (it should read) smart and clever enough 
 to have been able to cast the pillars hollow, and yet it 
 seems strange that no notice seems to be taken of it, if such 
 had been the case ; moreover, every thing points the other 
 way, that is, to the assumption that the pillars were solid ; 
 because we read that the clay-ground round Jordan was well 
 suited for a foundry, and the brass prepared was so immense in 
 quantity, and the workmen's integrity so tried, that it neither 
 could nor needed to be weighed out to them, which would scarcely 
 suit in this generation ; but from this account, we may assume 
 that these pillars were really solid. Now let us glance 
 roughly at what their weight would be, if solid. 
 
 The height of each was eighteen cubits, and twelve cubits 
 did compass either of them, (we would infer that to be the 
 circumference.) Let us now see what a cubit is. 
 
 The Cubit is a measure of length, used both by the ancients 
 and in modern times. The English cubit is half a yard, or 
 18 inches, and is said to have been originally taken from the 
 measure of that part of a man's arm between the point of the 
 elbow and the extremity of the middle finger ; but the J ewish 
 sacred cubit was a hand-breadth more, amounting to 21*888 
 inches, (Ezek. xliii. 13.) Some imagine the sacred cubit to have 
 been double the length of the common one ; and that the pillars 
 in the porch of Solomon's temple were thirty-five common cubits, 
 and but eighteen sacred ones in height, 1 Kings, vii. 15, and 
 2 Chron. iii. 15 ; but these texts may be otherwise reconciled, 
 by taking the height of one pillar to be almost eighteen cubits, 
 and the height of both taken together thirty-five cubits. It 
 is probable that the Chaldean cubit was but eighteen inches ; 
 assuming, then, that the sacred cubit was only used for sacred 
 purposes, such as immediately pertaining to the altar, we 
 will measure the pillars by the common cubit. 
 
IRON FOUNDING. 
 
 Height 27 feet, and circumference, say 18 feet ; the weight, 
 then, of one column would be something like 175 tons. 
 Hiram would require at least 180 tons of molten brass to 
 complete successfully his casting. We wonder if there would 
 be any scabs on these columns ; of course they would be cast 
 perpendicularly. We wonder how long the casting kept in a 
 liquid state, and if it was fed, and how the metal was run in. 
 We would infer that it was a loam mould, as the foundry was 
 in clay grou'id. And what shall we say of the furnaces, and 
 how many of them ? and, last of all, what of the appliances 
 for lifting the pillars after being cast ? 
 
 Hiram was a Syrian by his father's side, but by his 
 mother's an Israelite ; and we think that he would be cunning 
 enough to core these large columns ; then the thought arises, 
 had they been solid, that the difficulty of breaking them up 
 might have been the means of preserving some portion of them 
 even to this day. Be that as it may, from the accounts that 
 we can glean from the work tliat ho did for Solomon's temple, 
 Hiram was no ordinary moulder ; and he must have 
 thoroughly understood the art of moulding. Hiram's work 
 for Solomon seems to be the only account that we have of 
 foundiy work in the Bible ; but we must infer that casting 
 would be carried on in after years. 
 
 The casting of bells for churches seems to have been in great 
 favour with the ancients ; the fii'st bell is recorded as being cast 
 at Nola in Campania, a. d. 400. Bede first mentions bells 
 (large ones too) in England, about the year 670, and two 
 centuries afterwards they seem to have been common. 
 
 In A.D. 870, according to the historian of Croyland, one of 
 the Abbots of that religious house, gave to the church a 
 great bell, which he named Guthlac," and afterwards 
 six others, which were all rung together. Lardner says, 
 
 the use of bells of a small size is of great antiquity, as 
 in the J ewish ceremonies of the tabernacle, and afterwards in 
 
8 
 
 A TREATISE ON 
 
 the temple, bells of gold were attached to the robes of the 
 high priest." The largest bells in the world are, (according to 
 travellers) in China and Eiissia ; and it is said, that at Nankin 
 there formerly hung four bells of such enormous size that, 
 although not swung, but only struck with a wooden mallet, they 
 brought down the tower, and have long lain neglected among 
 its ruins. One of these bells is about 12 feet high, 7^ feet in 
 diameter, and 23 feet in circumference, its weight being com- 
 puted at 50,000 lbs., or 22 tons, 6 cwt., 1 qr., 20 lbs. 
 
 In St. Ivan's church at Moscow, there is a bell which 
 weighs 127,836 lbs., or 57 tons, 1 cwt., 1 qr., 6 lbs. This 
 was the largest bell known, until Boris Godunoff gave to the 
 cathedi^al of that city a bell weighing 288,000 lbs., or 128 tons, 
 11 cwts., 1 qr., 20 lbs. This was again surpassed by the bell 
 cast at the expense of Queen Anne of Eussia, and which 
 weighs, at the lowest estimate, 432,000 lbs., or 192 tons, 
 17 cwts. 0 qr., 16 lbs. This is the largest bell in the world ; 
 its height is upwards of 21 feet, circumference near the bottom 
 67 feet, greatest thickness 23 inches. This bell is on the ground. 
 The local tradition is, that the beam upon which it was 
 suspended in the tower was accidentally burnt in 1737. 
 Travellers suspect this to be a fable ; but as writers continue 
 to copy each other, the story continues to be rejoeated. The 
 fact is, that the bell remains in the place where it was originally 
 cast ; it 7iever ivas suspended. Lardner says, ''the Eussians might 
 as well attempt to suspend a first-class line of battle ship, with 
 all her guns and stores." It seems there is a large fracti;re in 
 this bell, caused through a fire in the Kremlin, the flames of 
 which caught the building erected over the pit in which the bell 
 remained. The metal was thus heated, and the water which 
 was thrown on it to extinguish the fire, caused a large fracture. 
 
 On festival days the peasants visit this bell as they would 
 an altar, and cross themselves as they ascend and descend the 
 steps leading to the pit. 
 
IRON FOUNDING. 
 
 9 
 
 Messrs. Clarke and Cripps, who visited this great bell 
 represent it as quite a mountain of metal. It is said that the 
 Nobles threw many pieces of gold and silver into the liquid 
 metal of which it was to be cast. 
 
 The bell of which we have already spoken and which weighs 
 57 tons, is suspended in the belfry of St. Ivan ; its circum- 
 ference is 40 feet 9 inches, and thickness 16^ inches where the 
 clapper strikes ; it is only rung on great occasions, and yields 
 the finest and most solemn tones which it is possible to hear, 
 vibrating all over Moscow with a deep and hollow murmur, 
 like the rolling of distant thunder. 
 
 The casting of statues in bronze, although belonging to the 
 fine rather than to the useful arts, may with propriety be 
 mentioned here, as it seems to claim great antiquity ; speci- 
 mens of the Greek and Roman workmanship being preserved in 
 various European Museums. Delphos, Athens, and Ehodes, 
 are reported to have each possessed 3000 such statues ; the 
 latter place was particularly famous for the colossal image, 
 which bestrode the entrance to the harbour, and which is said 
 to have been thrown down by an earthquake, b. c. 224, and 
 that the Saracens on their becoming possessed of the island, 
 sold it to a Jew, who, to carry it away, loaded 900 camels with 
 the brass. 
 
 In what manner the ancients carried on their operations in 
 obtaining casts from statues or models, we are not informed ; 
 neither is it known exactly what was the composition of the 
 metal they used. The Egyptian bronze we are told, consisted 
 of f brass, and only 1 of copper. Pliny says, the Grecian 
 bronze was made by adding lead, and J^o silver to the 
 Egyptian metal. We find that it was in the 13tli century 
 that bronze casting began in this country for statuary. 
 The brazen effigies of Eleanor, the Queen of Edward I., 
 King Edward III., and his son the Black Prince ; the 
 first, among female figures, and the latter among armed 
 
10 
 
 A TREATISE ON 
 
 men, are reckoned the earliest specimens of their age in 
 England. We have ample proof, then, that the art of casting 
 in sand and loam, whether it was for a temple, statue, or 
 a bell, was well known in mediaeval times ; and the principle of 
 moulding must have been at least as well understood by them, 
 as by its founder Tubal Cain. 
 
 At what precise period, and in what country the art of 
 casting in metal began, seems almost a futile enquiry. Mr. 
 Mushet, however, fixes the date of the discovery of the art of 
 casting of iron in this country about the year 1550, and 
 considers the process to have been an English invention. 
 Tomlinson also says, that cast-iron was not known in 
 England before the above period ; and that up to that time 
 all articles of iron were forged. 
 
 In 1624, Dud Dudley invented the process of smelting iron 
 ore with coal instead of charcoal, and from that date 
 we may say that casting of iron in reality began. Dudley's 
 name deserves to be recorded on the same bright page as that 
 which contains Brindley, Watt, Ark^vi'ight, and other illustri- 
 ous men, who have so greatly contributed to raise England to 
 her present high position. 
 
 COEE SAND. 
 
 Core Sand, when made into small cores, especially where 
 the metal round about them is light and thin, should be made 
 of weak and ver?/ porous sand ; but it must not be so weak 
 as to lose a certain amount of cohesive nature, to prevent 
 the core being properly made and handled. Two reasons call 
 for this : first, where the metal is thin, it is requisite that 
 the air should pass from the core at once ; which, if the sand 
 composing the core was strong and close in the grain, wouid 
 not be the case, and consequently the metal would not He 
 upon it, and a bad casting would be the result. Secondly, 
 core sand in light castings requires to be open and free, so 
 
IRON FOUNDING. 
 
 11 
 
 that they may come easily out of the casting. A slight rapping 
 of the hammer on the outside of a light casting should cause 
 a core made of proper sand, to run out immediately. To 
 get cores with this property, common moulding sand is freely 
 mixed with sharp sand ; in some cases pea meal, with which 
 grounds of porter, beer, or barm, have been mixed. This 
 mixture is only used in exceptionally thin castings. Common 
 moulding sand, as a rule, does well for the most of ordinary 
 cores, and in castings of a fair thickness, where the cores are 
 large. For heavy castings, the sand is different again. It 
 is to be observed regarding it, that the sand must be strong 
 and yet porous, and to get this the following is generally 
 done : — Common sand is mixed freely with loam that has 
 come from loam castings, a certain amount of horse drop- 
 pings, and in some cases saw-dust ; these are put into a mill 
 and ground for ten minutes. The result of passing the 
 sand through the mill, is to make it tougher, or in other 
 words, more cohesive, although with the mixture aforesaid, 
 it still possesses the quality of being porous and open. 
 This sand is termed mill'd sand," and is only used for large 
 cores, where the casting is large and the metal heavy, 
 Core sand, either for light or heavy work, must be damp, 
 but should it be too wet for small cores, the sand will adhere 
 to the wood or iron core-box, (more especially the wooden 
 ones), and prevent any thing like a smooth core being made. 
 In large cores, if the sand is too wet, it cannot be rammed 
 properly, besides it causes the core to require a needless 
 amount of drying. After a little experience on the part of 
 the core-maker, the requisite consistency is soon attained. 
 
 GEEEN SAND. 
 
 From the words green sand," it will be obvious to 
 the reader that it means sand in a green or natural state. 
 Any kind of sand wiU not do for moulding, it has to 
 
12 
 
 A TREATISE ON 
 
 possess two qualities ; first, a certain cohesiveness ; secondly, 
 it must be open and free. Belfast sand is in colour nearly 
 red, of a fine grain, and much, used in Scotland for moulding. 
 This sand does well by itself for moulding light work, such 
 as balustrades, grate metal, and all kinds of ornamental work. 
 No sand could be better. But in heavy green sand castings, it 
 requires to be mixed with sand of a stronger nature, and for 
 this purpose rotten rock suits well. This sand seems to be a 
 kind of decayed rock (freestone), its properties are great 
 strength and yet openness. The proper mixture is one of 
 rotten rock to three of Belfast, for ordinary casting ; whilst 
 for extra heavy castings, something like equal proportions 
 are used. This sand is used extensively in Scotland, 
 excej^t on the North-east Coast, where principally Erith, 
 commonly called London sand, is used, as it is much cheaper 
 than the sand from Belfast. Erith sand for moulding pur- 
 poses, is much more useful than Belfast sand, as it seems to 
 possess the proper grain for ordinary castings, and also does 
 well for. light work. In extra heavy castings, the part that 
 forms the top of the mould is usually mixed with a little 
 ground fire-clay in the proportion of one to twenty ; the fire- 
 clay strengthens the sand, but ought to be carefully mixed, 
 as too much fire-clay might work mischief. The sand 
 that requires to go next to the pattern is mixed with 
 coal dust to the extent that the job requires. Heavy green 
 sand castings, require much more coal-dust than light castings. 
 Coal dust is used for the purpose of causing the sand to 
 leave the casting freely. Ordinary work requires one part of 
 coal-dust to eight or ten of sand, light work one part to 
 fifteen. Belfast sand is all the better when mixed with 
 one to six parts of rotten rock, in order to strengthen the 
 facing of the mould. These mixtures being of the requisite 
 dampness, are riddled through half inch and quarter inch 
 riddles, and are ready for use. 
 
IRON FOUNDING. 
 
 13 
 
 DEY SAND. 
 
 Dry sand derives it name, not because it is wroiiglit dry, 
 but because it is dried in the stove after the mould is made 
 and finislied. Little need be said of its nature. Foundries 
 wbicb use Belfast sand, make their dry sand of rotten rock 
 and dried loam, in the proportion of one part to ten, and 
 where they have a pug-mill, it is easier and makes better sand 
 to pass it through the mill for a few moments. Where there 
 is no mill it is merely trodden with the feet, turned over, and 
 passed through two riddles. Erith sand is done exactly the 
 same, but dried loam broken up and riddled, would make 
 first-class dry sand without going through the mill. This 
 sand can be of any strength or even closeness in the grain, 
 owing to the mould being put into the stove and thoroughly 
 dried. No coal-dust is used in this sand to skin the castings. 
 It is either before or after being dried, (generally before) 
 blackened the same as a loam mould, with a coat of blacking, 
 (this blacking will be spoken of further on) which is put on 
 with a fine brush, or, which is better, a swab made of lint. 
 Castings made of this sand bring a better price in the 
 market than those made in green sand, as they are cleaner, 
 the metal is closer in the grain, and much better suited 
 for machinery, for reasons which will be given in describing 
 dry sand moulding. 
 
 LOAM. 
 
 Loam, the Spaniards, not inaptly call fango signifying 
 mud, being something like lime in consistency. There are 
 three kinds ; the first called fine or facing loam, used to form 
 the face of the moidd ; next, is core loam, presently to be 
 debcribed ; and the third is termed common building loam. 
 The fine (or facing) loam, commonly in use in England, is 
 principally composed of Erith sand, and the mixture is as 
 follows : — Five barrows of Erith to one of old dried loam, 
 
 c 
 
A TREATISE ON 
 
 got from moulds that have been used, termed in the foundry 
 ^'rubbish/' and two handfuls of cow hair (the longer the 
 hair the better, as it gives more cohesiveness to the loam), are 
 ground together in a pug-mill, with water sufficient to bring 
 it to the desired consistency. The hair, as it is added, ought 
 to be teased carefully out to j^revent it running into lumps. 
 Should the <Erith sand be of a strong nature (that is, clayey), 
 one haK more of old loam should be added, or a few shovel- 
 fuls of fine shar^D sand, this will prevent the loam from 
 forming cracks on the mould during the stage of drying. 
 Fifteen minutes' grinding will make it ready for use. Facing 
 loam bears the same relation to a loam mould, as facing sand 
 does to a green sand mould. It is called facing loam, because 
 it is used to cover the face of the bricks next to the casting ; 
 the common loam being merely used as a cement for the 
 building of the mould. 
 
 Core loam is made exactly the same as the fine, with the 
 exception that three or four shovelfuls of saw-dust, and the same 
 of horse droppings, are added, for the purpose of making it 
 more open and porous. For very small loam cores, where it is 
 diffiriilt for the cleaners to get them out of the casting, it is 
 good to add some charcoal blacking, just sufficient to make the 
 loam black ; such are steam way cores for very small cylinders, 
 slide-valves, &c. 
 
 The fii^st description of loam is very strong and some- 
 what close in its nature, and takes a great deal of heat 
 to dry it. When the mould is allowed to get cold after 
 being dried, it seems to absorb a certain amount of moisture, 
 and should the metal be then run into the mould, the casting 
 is liable to be faulty, or scabbed." Thus with this loam the 
 the mould should be put together when hot, and receive the 
 metal as soon as possible. Some foundries have pipes fitted 
 to enter large moulds, so that hot air may be blown into 
 them during the time of closing, and close up to the time of 
 
IRON FOUNDING. 
 
 casting. Clean castings can be made without such an elabo- 
 rate arrangement as hot air pipes, if the putting together of 
 the mould is done smartly while hot, when it should still (even 
 the largest of moulds) retain quite enough of heat to ensure 
 no evil result while casting. 
 
 Core loam (the second description) is easily broken, and has 
 to be carefully handled, the saw-dust, &c., added to it having 
 made it brittle. 
 
 The third description of loam is termed foundry rubbish,'' 
 or dried loam off castings, and is only used for bedding bricks, 
 filling up joints, and making loam bricks for cores. 
 
 But the loam in Scotland, which is of a very different 
 description, is made from iron sand, coarse in the grain, 
 and full of pebbles as large as marbles. It is the only 
 sand used for making lime, and it is called ^^iron sand,'' 
 from being taken from the iron districts of the river Clyde, 
 which supply the West of Scotland. The East is suj)plied 
 from the river Tay. It is taken from the heads of those 
 rivers to ensure it being fresh. Five barrows of sand are 
 put into the mill to seven shovelfuls of common red clay, 
 and water added till it becomes like lime ; it is then ground 
 for fifteen minutes, when it may be taken out for using. 
 Twenty years ago two handfuls of cow hair used to be put 
 into a mill full of this loam, but since that time the hair has 
 been left out, and with equally good results. This loam 
 is much easier dried than the Erith loam, being a great deal 
 more open and free in the grain, the moisture gets better 
 away; when dried it is ^'frush" and very easily broken, and 
 aU tender points in a mould have to be carefully strengthened 
 with f inch square or round iron. It does not absorb the mois- 
 ture so quickly as Erith loam, and the mould can be cast with 
 success when perfectly cold. To make the facing part of 
 the mould with this coarse loam requires great labour and 
 skill to bring the mould to a smooth state. A stranger to 
 
1(J 
 
 A TREATISE ON 
 
 the trade looking at a mould when in its rough state, Tvonders 
 how ever it can be made fit to turn out a fine smooth casting. 
 To plunge your hands among this loam on a severe frosty 
 morning, and build all day with it, is far from agreeable ; yet 
 the hands must be used, as the loam requires to bo scratched 
 on to the part of the brick which goes next the face of the 
 mould to make it adhere. A mould znade from Erith 
 loam is infinitely easier finished than a mould made from 
 Scotch iron sand, yet apart from its roughness the latter 
 is well adapted for loam moulding purposes, and it is to be had 
 very cheap. Rubbish ground into loam is here again ajoplied 
 for bedding the bricks on, and filling up the joints. Iron sand 
 loam for small cores does not require saAvdust or horse, dung- 
 except in rare cases, the sand being merely put through a 
 fine riddle into the mill. 
 
 Iron sand loam has, however, its disadvantages. It is bad 
 for the hands, when dried it will break ensily, and imijiense 
 trouble and time are necessary to bring the mould to a smooth 
 state. Against this, you have its singular adaptation for 
 receiving metal kindly ; unlike Erith loam, you can drop the 
 melted metal any height upon it, and you may fill the mould 
 when it has been cold for days, and make good castings. 
 The iron sand, being so open and free in its nature, requires 
 much less venting than Erith loam, as it is more open. Any 
 moulder accustomed to work with Erith loam, would find at 
 first some difficulties in working the iron sand loam. , Eirst, 
 on account of its extreme coarseness, the difficulty of bring- 
 ing it to a fine surface ; and again, he would be liable to 
 form vents where there was no necessity for them, although 
 this would do no harm, except that time would be spent 
 for no purpose. On the other hand, a person brought 
 up to working iron sand, or Scotch loam, would much more 
 readily fall into the way of working Erith loam, the fineness 
 of which would save him a great deal of trouble, as will be 
 
IRON FOUNDISG. 
 
 17 
 
 shewn when we come to treat of moulding with these two kinds 
 of loam. The only difficulty to guard against would be in 
 venting ; he might vent too little, and that might lead to bad 
 results ; an observant moulder, however, by a little practice 
 will soon get over this difficulty. 
 
 Our experience of the two loams leads us to believe that 
 Erith loam is the best upon the whole. It is Yi'ij much 
 pleasanter to work, and with due care first-class castings can 
 be produced with it. 
 
 COEE MAKING. 
 
 The word Core " will convey its purpose to the reader, it 
 being the internal part of a mould round which the metal flows. 
 The core " is the most important part of a mould, for upon 
 the drying thoroughl}^ and taking the vent off properly, 
 depend wholly the success in making a casting, therefore 
 to insure a sound casting those two things are indispensable. 
 
 The apprentice at first begins with making small cores in 
 sand, and this core-making is the gamut of moulding. All 
 the best moulders have, as a rule, been good core makers. 
 
 The apprentice, at his outset, has the most simple of cores 
 to make, such as square and round, from half an inch diameter 
 up to three and sometimes four inches, and from two and three 
 up to twelve inches in length, which latter length is generally 
 the limit of a core-box. All cores above two inches in length 
 require something to strengthen them ; that is, something for 
 the sand to cling to, and this is done by inserting an iron, of 
 the length of the core, into the centre of the core-box, before 
 ramming in the sand. This iron, of course, must be in pro- 
 portion to the core, viz. a round or square core of half an 
 inch diameter will only admit of a fine piece of wire, 
 
18 
 
 A TREATISE ON 
 
 whereas a core of three times that size will admit an iron of 
 nail-rod ; besides this iron, a vent wire must be put in, which 
 must, like the iron, be in proportion to the core. It is laid 
 alongside the iron. Eound core boxes are made in two parts, 
 and should be made of cast iron, as boxes made of wood soon 
 become oval ; the two parts of the box should be carefully 
 fitted together, then bored out to the required size. The core 
 iron before being put into the sand is made wet with clay 
 water thickened until it becomes like cream in consistency ; 
 the box may be rammed either on end, or each part separately ; 
 in the latter case a little clay water is run along the centre of 
 each part before joining them together, so that they may 
 adhere ; after the core is rammed, the vent-wire is withdi-awn, 
 which leaves a clear space thi-ough ; the core is then complete. 
 Square cores are much easier made than round, as the box 
 being open, is easier rammed. A small hole is drilled in 
 the end of each part of the box to admit the vent-wire being 
 withdrawn. 
 
 When the beginner can make these cores properly, he gets 
 others of a more intricate nature, in wood core boxes, and as 
 these are of various shapes and sizes, to suit the different 
 forms of castings, the apprentice has ample opportunities to 
 become a good core maker. He ought to bear in mind, 
 and it is the duty of those over him to let him know, that on 
 making cores carefully and well, at the same time smartly, 
 depends in a great measure his future success as a moulder. 
 
 When cores are of a considerable size, the irons to keep the 
 sand together should be made of cast iron, as they are much 
 cheaper, and also more easily taken out of the casting by the 
 cleaners. In large cores the vent wire is not used ; ashes do 
 the duty of the vent wire. The ashes should be clean, that 
 is, free from dust. In ramming the sand, a certain cjuantity 
 of ashes is put into the centre of the core. During the 
 process of pom-ing the metal into the mould, the gases from 
 
IRON FOUNDING. 
 
 19 
 
 the mould pass easily througli the ashes, and from thence 
 to the outlet or vent, which the moulder has provided for 
 their escape. Care must be taken that the ashes are not too 
 near the surface of the core ; in that case a risk is run 
 of that j)ortion of the core being destroyed, it being weak in 
 that part. Of course when that takes place it would be a bad 
 casting. In iron sand two or three inches is quite a safe distance 
 to leave. Erith sand would do with haK of that distance, being 
 closer in the grain and tougher, and consequently more able to 
 resist the pressure. The core maker should bring his ashes 
 close to the place where the vent is intended to be taken off by 
 the moulder who is going to use the core, and it is the moulder's 
 duty to see that his core is properly dry and the vent good 
 before he puts the core into the mould ; the larger and freer 
 the vent is all the better ; in fact, the gases from a core 
 cannot come off too quickly. 
 
 It has been said, and by experienced moulders, that a 
 core 12 inches square and completely surrounded with 
 metal, could bo ventilated with a tube one-eighth in 
 diameter ; but we have hot yet known the moulder who has 
 done it. We, however, believe that it might be done, but not 
 in ordinary castings. For instance, if the core was made very 
 strong, and the metal round it was not less than three inches 
 thick ; but with an ordinary thickness of metal, say one 
 inch, it would be madness to cast it with such a vent. 
 The least vent that ought to be used in a core of that size 
 should be half an inch. But that is not the principle a core 
 maker shoidd go upon ; the larger he can get his vent the 
 better for the casting ; if the vent cannot be made large, then 
 let him arrange for more than one vent. Ashes make the best 
 vent that can be used in cores, because being so porous, they 
 absorb a certain quantity of gas, and they also afford free 
 passage for the gas that they cannot take in to pass away to 
 the place intended for its exit ; and we may even mention 
 
20 
 
 A TREATISE ON 
 
 another reason, and a very important one ; that is, should 
 metal, through inadvertance or through a weak part of the 
 cire, find its way among them, it seldom does any harm to the 
 cMsting, unless the metal travels right through them and 
 chokes the outlet, which would cause serious consequences ; 
 this, however, seldom takes place. 
 
 Some foundries adopt straw or hay ropes to form vents in 
 loam cores, especially for steam passages in cylinders. Cores 
 of that kind, although many good ones can be made with such 
 vents, are not quite so safe as those made of ashes, the 
 danger being that in some parts of the core the straw may 
 come too near the surface, and cause a small crack, admitting 
 the metal into the vent, which may run from end to end of 
 the core, and thereby cause a bad casting. This does not 
 happen with ashes, as the metal cannot run far until it sets. 
 Straw or hay were much in use for cores twenty years ago, 
 but are now almost wholly discontinued, ashes having taken 
 their place. 
 
 In jobbing foundries pipe cores for three-inch pipes are 
 still made with straw ropes ; an iron tube an inch bore and 
 twelve inches longer than the required length of the casting, 
 perforated every four or five inches with in. holes, is covered 
 with a small hay or straw rope, and afterwards with a coating 
 of loam up to the size of the inside of the pipe required. 
 The small holes in the tube convey the gases from the loam 
 into the tube, and it thus passes freely out at both or either 
 end. Care must be taken not to burn or even scorch the 
 straw. Many castings are lost, and even core tubes destroyed, 
 through parts of such cores having been subject to too much 
 heat, which burns out the straw, allowing the metal, if the 
 core should break, to get into the tube or core bar. 
 
 Cores for columns are made in the following manner : The 
 core is made of a size to suit the column ; for instance, a 
 column twelve inches diameter, and the metal an inch thick, 
 
IRON lOUNDING, 
 
 21 
 
 should have a core ten inches in diameter ; this woukl require 
 a hollow core bar of cast iron six or seven inches diameter, per- 
 forated like the smaller one, Avith holes nine or ten inches 
 apart, the holes being larger than for the smaller one, or about 
 f inches diameter. These holes are either round or square. 
 
 One course of straw rope is enough for any diameter of 
 core, more do no good, although under certain circumstances 
 four and five courses are used. As when a foundry has not 
 a core bar to suit exactly, and only a few castings are wanted, 
 to save making a suitable one, they use a smaller one, and 
 make up the deficiency with ropes. Now, the evil of this is, 
 that if the core gets too much heated in the stove, if even not 
 exactly burnt, it becomes what is called baggy,'* that is, 
 slack on the core bar through contraction. Assuming this 
 core to be for a column cast horizontally, and ten or twelve 
 feet in length, and that the core maker has even raised one or 
 two studs of iron from the core bar to the surface of the core 
 to sta}^ it in its place, even then the column may be thin on 
 the top of the casting to the extent of v^- inch, the bar 
 having perhaps retained its place, but the whole body of the 
 straw ropes and loam being slack, the core has been lifted by 
 the pressure of metal. In this way many pipes, and columns 
 for important structures, are thin on one side. 
 
 Again, cores made with such a body of straw ropes are 
 very difficult to dry, and if they are not quite dnj, the inside 
 of the casting will be sure to be faulty. For fear of this the 
 core maker is liable to heat the core too much. Cores of this 
 kind, to ensure them being well made, should be put into 
 the stove after each one or two courses of straw, well rubbed 
 with loam, have been added. We will assume that a core 
 still wants three inches to bring it up to the required size ; 
 a board with a bevelled edge is laid upon the trestles on 
 which the core revolves, and kept back J of an inch, loam 
 is then well rubbed over the core until the space is filled up ; 
 
22 
 
 A TREATISE ON 
 
 it is then dried again, taken out, and tlie same board kept 
 again f back ; this will bring it np to the required size, 
 and a strong and safe core is made in this way. A core Trill 
 take a little more time, but all things considered, it may 
 be said to be quicker in the end than running all the ropes 
 on at once, as you are sure of a casting of equal thickness. 
 In foundries where p)ip^s are made a speciality, the cores 
 are machine made, with only f to 1 inch of loam on the bare 
 core iron. 
 
 VENTING COEES AND MOULDS. 
 
 To know how and where to extract the gases from a core 
 or a mould, is one of the most important acquirements of a 
 moulder. -Castings are often faulty, ^and even sometimes 
 bad,) through too little attention being paid by the moulder 
 to the minor parts of a mould, or giving little attention to 
 a small core. Take, for instance, a snug, or a flange, where 
 small cores are put in the mould to save boring in the casting. 
 How often have we seen these snugs and flanges blown to a 
 shell, (or rather like a shell,) and the snug or flange having to 
 be burnt on afterwards, thereby endangering the whole 
 casting, and this occurring often, from the want of a vent in the 
 core. And more especially does this apply to small castings, 
 where the metal is light, (or thin,) and consequently little or 
 no pressure of metal in the mould. The higher part of a 
 casting, where the pressure (or weight of iron is least,) seems 
 to suffer most from the want of a vent in the core. Small 
 cores in the bottom of a mould of an ordinary size, (either in 
 loam, diy sand, or green sand,) seem to cause no trouble or 
 harm to the casting, or even mid- way of a mould, and such 
 can only be accounted for by the part of the mould where 
 
IRON FOUNDING. 
 
 they may be located in, having a greater pressure of metal 
 than the strength of gas that the core may contain. When the 
 moulder is satisfied that such is the case, a vent in a small 
 core can be dispensed with. 
 
 We will not say that snugs and flanges are blown in ever}" 
 instance, owing to the want of a vent. They are often blown 
 (more especially in green sand) through the cores becoming 
 damp, having absorbed this dampness from the mould, they 
 having been put in the mould, possibly, five or six hours, or 
 even longer, before the mould was cast, in this case, they have 
 the more need for a vent. Too little attention in many 
 instances is given by moulders to those little cores on the top 
 of their moulds, and more especially, as I have already 
 mentioned, does this apply to small castings. 
 
 Again, something else is to be considered. Why it is im- 
 perative that small cores should be vented, and that is, the 
 state or condition of the metal during the process of casting. 
 
 When the metal is hot, or lively, being in a very liquid 
 state, the want of a vent will aftect the casting scarcely so 
 much as it does Avhen the metal is in a dull or cold state. In 
 the hot state, the metal is more able to maintain its position 
 or place in the mould, having life in it, as it were, to resist 
 and combat the gas that may find its way through the porous- 
 ness of the sand which composed the core ; but, withal, the 
 part of the casting is liable to be blown to a certain extent. 
 
 AVhen the metal is dull or cold, having little or no life in 
 it, or even moderately hot, the blown part will be much more 
 extensive than when the metal is full of life. In this stage 
 it soon becomes dead, or (technically speaking) setSy and the 
 space round the core is vacant, only a shell remains, merely 
 shewing the outside formation of a snug or flange. 
 
24 
 
 A TREATISE ON 
 
 Fig. 1. 
 
 \\\\\\\\\\\\\\\\\\^^^ 
 
 Fig. 2. 
 
 7^ 
 
 V O O ^ 
 
 v\vyvVs.\\\\s\Vs\\x\\.vvv\\\\\'\v. 
 
 In diagrams 1 and 2, we have a view of two snugs, and a 
 flange, as they occur often when cast without a vent in the 
 €ore, or when the core has been a long time (say twelve hours) 
 in the mould, and has become damp. The snug that is most 
 extensively blown seems to point to any of the following 
 causes : — 
 
 First, the core having no vent, or, having a vent, due pro- 
 vision not being made by the moulder to take it away. 
 
 Secondly, the core being damp, with a vent in it, and 
 having been taken off, but the metal has been dull when cast, 
 
 Thirdlj^ the core may have been made of very strong sand- 
 rather damp, and rammed too hard, and yet having a vent 
 in it. 
 
 The snug not so much blown may have had any of the 
 above-described cores, but the metal was in much better con- 
 dition, being hotter. 
 
IRON FOUSDIXG. 
 
 25 
 
 The flange shewn in No. 2 diagram, has been affected by 
 the same causes as the snugs were ; and although other 
 agencies may cause a blown part in a snug or flange, (as 
 we have already shewn,) the want of a vent is the primary 
 one. 
 
 The snugs and flange present this appearance when they 
 form the highest part of a mould or casting, with their edges 
 looking up ; but when they are on the flat, the blown parts are 
 not so deep, the gas finding a wider range over the surface. 
 With the flange on edge, all the gas is confined in a corner, 
 and remains there, to the exclusion of the metal. 
 
 When we thus see the importance of attending to small 
 cores, such as inch round, or square, up to three inches, 
 what shall we say of large cores. 
 
 Every moulder who may have cores in the piece of work 
 that he may be engaged at, looks and notes with some little 
 anxiety, during the time the metal is being poured into the 
 mould, if his vents are all burning clear. 
 
 When a vent from a core becomes stopped with metal, either 
 from the metal having found its way into the core, or from 
 the core changing its position in the mould, and allowing the- 
 metal to come in contact with the outlet of the vent, but not 
 in a sufficient quantity so as thoroughly to obstruct the vent, 
 the flame from the gas Avill be quite different to what it would 
 be if there had been no metal in the vent at all ; when par- 
 tially stopped with metal, it emits a deep yellow colour, not 
 unlike the flame from coal. When the vent is free, and the 
 core thoroughly dry, a deep blue flame, tipped with a bright 
 yellow, is then seen. The gases from carburetted hydrogen 
 and carbonic oxide, on coming into contact with the atmos- 
 phere, cause this blue flame. 
 
 A partial obstruction of a vent seldom causes any bad 
 result, if we except some instances, such as when the core is 
 totally surrounded with metal ; to wit, pistons, cylinder 
 
A TREATISE ON 
 
 €Overs, steam ways for cylinders, or in other eastings where 
 the metal may be very thin. 
 
 Cores are always safer vented from the top, as the gases 
 naturally seek to rise ; but when this cannot be done, a 
 pipe (two inches or more in diameter) should be laid in the 
 bed of the mould, immediately below where the core is 
 intended to rest, and careful provision made that it is kept 
 there. AVhen in a loam mould, it can be bolted down to the 
 plate that the mould is built upon. When in green or dry 
 sand, a chaplet on the top will suffice ; the chaplet of course 
 to be in strength proportionate to the core that is to be kept 
 down. 
 
 When the vent passes from a core through the side of a 
 mould, either sand or loam, that core should be held to its 
 position by means of a bolt, or in some cases, when the core 
 is small, a strong wire will do equally as well ; the bolt or 
 wire being made fast to the core iron, so that in the event of 
 the mould slightly yielding during the cast, the core would 
 be held to its place. We believe, that wherever there is a 
 possibility of doing it, all cores should be held to the place 
 where the vent of the core leads from. When the mould is 
 very suddenly filled with metal, it tries the stability of the 
 cores very much, and too great precaution can scarcely be 
 taken to keep them in their places. 
 
 In casting marine engine cylinders it is the rule to fill the 
 large core with sand, not for the purpose of strength- 
 ening the core, but only with the intention of having no 
 hollow space for the gas to accumulate. Supposing no sand 
 was put in the core, the probabilities are that the top of the 
 mould might be blown off. 
 
 In casting sugar pans it is not customary to fill their cores 
 with sand, however large they may be ; they are cast hollow 
 and the vent taken from them, in a manner that no other 
 cores are done, that is, when they are cast convex up. 
 
IRON FOUNDING. 
 
 27 
 
 When the mould is dried and finished, ready for the metal, 
 it is lowered into a pit or hole in the foundiy floor, ready to 
 receive it, a gutter or trench having been previously made 
 where it is resting. A piece of fine sieve or wire-work is laid 
 close to the edge of the plate on which the mould is built, the 
 wire work covering the trench. A round or square piece of 
 wood, three inches diameter and four or more feet in length, 
 rests upon the sieve, which piece of wood is termed a 
 ^' vent pin.'' The pit is then rammed up to the top, when the 
 pin is withdrawn, and another piece of wire-work like the first 
 is laid upon the hole that the vent-pin had made. This in turn 
 is covered over with straw and sand four or five inches 
 deep, and the vent is complete. This vent acts in the same 
 manner as the celebrated " Davy lamp." 
 
 It is not only necessary that a moulder should know how 
 and where to lead the vents from the cores and mould, but is 
 is of vital importance that these vents should be secured from 
 the metal. When metal finds its way into the vent or vents 
 of a mould, the casting is seldom materially affected, it 
 may be faulty, but in very rare cases is it a bad one. 
 
 Castings made with green sand are more liable to be faulty, 
 when the vents of the mould get stopped with metal, than 
 either dry sand or loam castings. Not so when metal blocks 
 up the passage for the vent in a core, even of a very moderate 
 size. The casting invariably is a bad one. The important 
 part, then, of the moulder is seeing and knowing that the 
 vents from his cores are properly secured ; that due provi- 
 sion has been made in the mould to get at these vents, so that 
 they can be loamed all round the joint with wet loam, and 
 then well rammed up with sand round the tube that conveys 
 the gas from the cores to the outside of the mould. This is of 
 essential moment to the moulder, and cannot be too much - 
 overrated, and should be particularly noticed in side vents, or 
 vents taken from the under part of a core. 
 
28 
 
 A TREATISE ON 
 
 During the process of casting, moulders are busily engaged 
 ligliting the vents leading from the cores and mould ; and 
 this is quite essential, for two reasons — it encourages the gas 
 to the mouth of the pipe, and prevents it from striking 
 back upon the cores or mould. 
 
 In casting a large green sand mould, and when the mould 
 is nearly filled with metal, a loud report is sometimes heard ; 
 gas has been gathering somewhere round the mould, and has 
 suddenly fired or taken light. This is not good for a green 
 sand mould, as it is liable to shake and start tender or weak 
 parts of the mould, and thereby do mischief. To provide 
 against that, shavings are profusely spread at intervals round 
 the mould, and set on fire immediately before the cast, the 
 gases then light when generated. This striking back of the 
 vent is prevented, when casting hollow work, by the vent 
 being made as already described in casting a pan. 
 
 Supposing no sieve or wire work to be used, merely an 
 open vent from the bottom of the mould, and let a spark of 
 metal come near the vent, an immediate blow-up of the whole 
 mould, with all its cramps and bars, is liable to take place. If 
 no light or spark goes near the vent, no harm will occur. 
 
 When we again dilate on moulding further on, occasion 
 may be had to refer more fully to venting cores. 
 
 Tenting moulds in green sand or dry sand is principally 
 done with a steel wire from an eighth round to three-eighths 
 or even half an inch, a small wire about twelve inches long, 
 with a wood handle on it to protect the hand, and intended 
 for ordinary castings. The thick wire, with a cross handle 
 on it, is only used for the heaviest of green sand and 
 dry sand. In ordinary-sized moulds, when the pattern 
 has been rammed, and the top part that covers the pattern 
 ready to be lifted off, the small wire is used freely, 
 passing through the sand till the point touches the pattern. 
 The top part being now lifted off, exposing the surface of the 
 
IRON FOUNDING. 
 
 2(9 
 
 pattern, a ridge is made with the point of the trowel about 
 tliree inches from the edge of the mould ; this ridge is mad^. 
 in order to connect all the vent wire holes that are about to 
 be made into one channel, it becomes in reality an air passage 
 or channel. The end of that channel must be carried out 
 further than the top -part covers ; the edges of the mould next 
 the pattern are now freely swabbed with water, and the 
 channel or air passage as well ; the vent-wire is then passed 
 down as far as the pattern reaches, a space of two or three 
 inches being kept between each little hole. Care has to be 
 taken that no metal gets into that channel to fill those vent 
 holes. Should the top part that covers the mould strain or 
 lift the thickness of a tenth of an inch, the vents are choked. 
 This would cause no visible eruption in casting, Lut it is 
 liable to make the casting scabbed. 
 
 The heavy green and dry sand moulds are done in precisely 
 the same way, only with a slight exception, that the job is 
 all vented before the top part of the box is put on. When 
 the pattern has been rammed up within three inches of 
 the top, the large vent- wire is then (after a gutter or channel 
 is made) passed freely down the sides, say six inches from the 
 pattern ; when that has been done, a straw or hay rope is 
 laid upon these holes, then a few clean riddled ashes, till you 
 cannot see the rope. Thi'ee or four branches (or more, as the 
 case may be) are led back from this main one, made in the 
 same manner. Vent-pins, one and a half inches round, are 
 put to those branches, and the finishing of the ramming up 
 to the top of the pattern follows. In this way are these vents 
 secured in the event of the top part straining. 
 
 Besides the top and sides of a green or dry sand mould, 
 the bottom part also requires venting, and to attain this, 
 much depends upon the shape and size of the pattern ; for 
 instance; a square or round plate, three feet and one and a half 
 
30 
 
 A TREATISE ON 
 
 inclies tliick, requires the vent wire slightly bent, so that it 
 may pass below it. 
 
 Castings that take the form of an H beam require to be 
 carefully vented, to avoid scabs and a bad casting. If the 
 pattern is light and easily handled, the part of the pattern 
 that is to go for the bottom of the mould is filled with sand 
 made sufficiently hard, and the vents made with a small wire. 
 The pattern is carefully and quickly turned over on a bed to 
 receive it, and when the pattern is ready to be drawn, the 
 side vents are made and intended to communicate with the 
 vents below. The top vents are easily made, as they pass 
 straight through the top part to the pattern. 
 
 When the job is large, and the side vents cannot take the 
 gas from the bottom of the mould, an ash or char bed is put 
 into the hole made to receive the pattern, which bed should 
 not be less than three inches deep, and three or four 
 inches of sand should be between the pattern and the ash bed ; 
 four or more pipes, two or three inches diameter, are led from 
 this bed to convey the gas from it ; the vent-wire is used freely 
 from the face of the mould down to the open bed, care being 
 taken to close up the mouth of the vent-holes next the casting. 
 This method of venting is always done in the early stage 
 of the job being moulded, and when the bottom of the mould 
 has only taken the impression of the pattern. It will thus 
 be seen that enough has been said to shew how important 
 the vent-wire is to a sand moulder, more especially in green 
 sand. The vent- wire is an important tool ; many jobs cast in 
 dry sand would take no harm in not being vented, which 
 would take serious harm in green sand. This occurs owing 
 to the former being dried, which rather changes its nature, 
 in becoming more porous as it were in itself, and the metal 
 lies more kindly to the mould, especially if it be warm. The 
 dry sand has another advantage, it is better able to resist a 
 commotion of the metal when it takes place through an 
 
IRON FOUNDING, 
 
 31 
 
 insufficient venting, than the green sand is. If a green sand 
 mould shew even very little irruption after being cast, either 
 through the sand being a little too damp, or not properly 
 vented, some part of the casting is sure to be faulty, and in 
 many instances the cause of its rejection. 
 
 The green sand moulder, therefore, looks upon his vent- 
 wire as something of ffreat imj^ortance. The loam moulder, 
 on the other hand, seldom or ever uses the vent wire, in fact, 
 not at all when the loam is made of iron sand. When made 
 from Erith sand, it is sometimes used for top parts of moulds, 
 the Erith being so much closer than iron sand. The o^^erator 
 will then use straw and hay to vent his mould. Into all 
 corners, up the sides of brackets, and blow flanges, the straw 
 rope is used freely. Care must be taken not to have them 
 too near the face of the mould, not less than an inch. If 
 these straw ropes were within a quarter of an inch from the 
 face the air might blow that part in, and thereby cause a 
 scab on the casting. An inch gives sufficient strength to 
 resist that taking place. When the loam mould is properly 
 dried, the straw ropes are burned out, thus causing a space 
 for gas, as the vent-wire does in the sand. When .a loam 
 mould is rammed all round with sand, loose straw is put to 
 those vent holes, and led to a vent-pipe of two or thi-ee inches 
 in diameter ; and when cast without ramming uj), as some 
 founders do, the vent has free course to blovv off. Those 
 straw or hay ropes only apply to the sides of a mould, the 
 bottom or bed being vented in the same manner as the green 
 or dry sand, namely, with ashes, which are applied somewhat 
 differently. Instead of a bed of three inches, the bricks are 
 kept fully an inch apart, and the ashes fill up the space 
 between, an inch of loam only intervening between the bricks 
 and ashes from the casting ; even two inches will do, but with 
 any more than that the loam is liable to crack and cause 
 trouble to the moulder, and is not good for the casting. 
 
A TREATISE ON 
 
 The rents of a loam mould being cliokecl, from whatever 
 cause, never cause an eruption, that is, are not visible to the 
 moulder after being cast ; a certain commotion must take 
 place, but it is of so slight a nature that it has not poorer to 
 move the heavy weight of metal above it. But the mould is 
 liable to be faulty, as in the case of the green sand ; neg- 
 lecting or omitting to take the vent from those burnt straw 
 ropes is infinitely worse than having no ropes at all ; because 
 by using ropes a vacuum is formed which becomes tilled with 
 gas, and if the proper road for its outlet is stopped, where 
 will it go to ? To the weakest part certainly, and that will be 
 into the mould ; to get there it must press a portion of the 
 mould into the metal, and thereby cause a hollow iix the 
 casting. It would have been better in that case had there 
 been no ropes at all ; the mischief might not have been quite 
 so bad. 
 
 Venting of loam moulds depends in a great measure on 
 how they are built ; and when we come to describe loam 
 moulding the reader will see that this is the case. It should 
 be borne in mind by the moulder, not to use straw ropes 
 unless absolutely necessary, for two reasons ; first, that they 
 do harm when not attended to ; second, it is a waste of time 
 and material when they are not wanted. 
 
 SCABS AND SCALES— THEIE CAUSE AND 
 EFFECTS. 
 
 A scab upon a casting, however fair it may be in other 
 respects, is like an excrescence of the same name upon a 
 human being, very unpleasant to look upon. The flanges of 
 a casting may be straight and regular, snugs and belts per- 
 fection, and it may appear perfect, whilst the practised eye 
 discerns a scab. A scab is not only unpleasant to look 
 upon, but when it occurs in an important part of the casting 
 
IRON lOVNBIKG, 
 
 may be the means of its condemnation. There are tlii^ee kinds 
 of scabs with, which castings are liable to be affected : — First, 
 there is the raised scab ; second, the hollow or dumb scab, 
 sometimes called a buckle ; third, and worst, one that com- 
 bines the first and second. 
 
 The first, as it is here shewn, (No. 3 diagram) can be 
 chipped or planed off, leaving nothing but a bright place to 
 shew where it has been. These scabs may be caused (1) by 
 the green sand, dry sand, or loam of the mould being too 
 weak or too strong ; (2) by the metal washing away some 
 part or parts of the mould while being run in ; (3) by the 
 green sand being too damp, or the dry sand or loam not 
 perfectly dry. 
 
 Although this scab can be chipped off, bored out, or planed 
 off, still the portions of the mould washed off must have 
 found their way to some other part of the casting, where they 
 will form what is called dirty place" ; and this dirt very 
 often seems to find its way to an important part. This scab is 
 made during the time that the mould is being filled with 
 metal. It will be obvious to the reader from the above that 
 though the scab of itself may be easily got rid of, the loose 
 material floating about may be the means of causing a bad 
 
34 
 
 A TREATISE ON 
 
 casting. These scabs are never more than three-eighths of 
 an inch thick, but may be of any extent in length and 
 breadth. A\lien only one or tTvo appear on a casting, the 
 running in of the metal has had something to do ^rith it ; 
 but ^hen the casting is a mass of scabs then the mould has 
 been wet, or the material has been bad. 
 
 The second, or dumb scab, is of more serious consequence 
 to a casting than the first, the form of it being shewn on 
 !No. 4 diagram. 
 
 It runs in all kinds of fantastic shapes, and is thi^ee- eighths 
 and even sometimes half an inch deep. It will be seen at 
 once how annoying this scab is when it occurs on the, part 
 of a casting that is to be planed or bored. Take a cylinder of 
 any weight, from half a hundi^edweight up to thirty tons ; if 
 a few of these scabs are in the inside where it is bored out to 
 fit the piston, and supposing them only to be one-quarter inch 
 deep, the casting runs a risk of not passing. When they are 
 three-eighths or half an inch deep the casting is almost sure 
 to be spoiled, as it cannot be turned out. These dumb scabs 
 are seldom found on green sand castings, but frequently in dry 
 >sand and loam, and loam cores in green sand. They will 
 occur on an}- part of a casting, but seem to frequent more the 
 round parts of a mould ; of course that will be the hollow part 
 of the casting. When they are on parts of a casting that are 
 not to be planed or bored, it is difficult to know what to do with 
 them : the casting, however, may not be any worse except in 
 ajipearance. 
 
 The fii^st cause of this dumb scab is the mould not being 
 cj^uite dry, or having absorbed moisture again, and a little 
 steam being generated by the heat of the metal, close to the 
 face of the mould, pressing a slight poii:ion of it out before 
 the metal is set. It seems, therefore, that the mould is filled 
 with metal before these scabs are made. 
 
 The third kind of scab is a combination of the fii'st and 
 
IRON FOUNDING, 
 
 35 
 
 second ; it sliews itself on a casting in the form marked on 
 diagram No. 5. 
 
 At the first look of this scab, it appears as if it was one of 
 the first spoken of, and could be chipped off, but that is not 
 the case. The edges have no hold of the casting, as you can 
 enter the point of a thin chisel between the scab and the 
 casting in many places ; there is loam between the casting 
 and the scab, and with two or three strokes of a hammer the 
 major part of the scab will come off, shewing a dumb scab, 
 with a thin portion of loam running completely through the 
 metal. It will thus be obvious that when this kind of scab 
 is found on a part of the metal which has to be planed or 
 bored the casting will be rejected ; and when it occurs where 
 steam or water has to pass it stands a poor chance of passing 
 unless it suits the engineer to mend it, which depends upon 
 whether he is really a practical engineer; if not, as is too 
 often the case, the casting will be condemned. 
 
 The same cause, in this case, but greater in degree, has 
 been at work in causing this, the tvorst of all seals, as occa- 
 sioned the dumb scab. The generated steam has had power 
 to press that portion of the mould opposite to it right through 
 the thickness of the metal, which portion thus forced off 
 never exceeds -i~G-ths of an inch in thickness ; in fact, it 
 requires the blade of a knife to scrape the loam out. This 
 displaced portion of the mould seems to get wedged in, as it 
 were, between the outside and inside of the mould, and it 
 remains there. This takes j)lace more frequently with Erith 
 loam, or dry sand, than with iron sand loam. This kind of 
 scab does not occur often, but, knowing that it happens at 
 times, it is well to speak of it. Seeing that the dumb scab, or 
 buckle, is the most prevalent in casting, we cannot pass with- 
 out saying something further about the causes of it. 
 
 We have said already that those kind of scabs are most 
 seen on the hollow parts of a casting ; for example, on the 
 
36 
 
 A TREATISE ON 
 
 inside of cylinders. Even wlien the mould is quite dry, and 
 tlie material composing it good, if the core is a small one, 
 say four feet diameter, and whole instead of half bricks have 
 been used in building it, this core will be very liable to form 
 dumb scabs. The joints of the bricks not being equal, a 
 great body of loam gets next the face of the mould between 
 those parts, and contains the most gas, which will escape by 
 the easiest place, and that is the face of the core ; in doing so 
 part of the core may be forced out. Again, dumb scabs may 
 be caused by the loam being too strong and clayey ; if this 
 is the case, large cracks will occur all over the mould, and if 
 they are not properly filled up, dumb scabs may be the result ; 
 more especially will this take place on the bed of a mould, 
 because, the mouth of the crack only being stopped, the gas 
 rushes from the bed, and forces the filling u^) of the crack 
 into the metal ; and, should the mould be damp, the steam 
 will co-operate with the gas, and in this way cause no small 
 damage to the casting. It would be better that the cracks 
 were not filled up than that it should be done imperfectly. 
 This applies to loam moulds only, for gi^een and dry sand 
 never crack. 
 
 As wide joints next the face of a mould in loam (shewn in 
 Figure 6,) are dangerous, this evil has to be carefully 
 avoided in propellers, which are castings very liable to dumb 
 scabs, especially at the curve close to the boss, the chief 
 reason being that there is often too great a body of loam at that 
 
IRON FOUNDING, ^7 
 
 particular place. In drying the mould steam gathers bet^veen 
 the bricks and the loam causing a slight space ; and when 
 the mould is filled with metal, the space fills with gas, which 
 forces the loam (as has been said already) into the metal, 
 thereby causing those indentations shewn on the propeller 
 blade, Figure No. 7. 
 
 One word more about dumb scabs. Air or gas not getting 
 away from the face of a mould into its proper channel may 
 cause scabs, but dampness is sure to do it, and if both of these 
 
38 
 
 A TREATISE OiJ 
 
 combine a very poor easting is the result, more especially 
 when the mould is cold. 
 
 All persons who have had much to do with castings will 
 have noticed in some which have been cast in loam that dark 
 lines are all over the body of them in every conceivable shape, 
 a perfect map in fact. If these dark lines are examined 
 closely they will be found to be slightly hollow. The moulder 
 gives them the name of veins,'' so called, we presume, from 
 their resemblance in form to those of the human body. These 
 veins are caused by the cracks that have been in the mould. 
 Every vein has been a crack in the loam, too small to be 
 stopped up with it. The mouths of these cracks get filled up 
 with blacking, and the air presses it into the metal, producing 
 thereby dumb scabs in lines. These veins occur most fre- 
 quently on the sides of a casting ; they are seldom if ever 
 next the bed, o^ing to the blacking being able to run to the 
 bottom of the cracks, filling them up ; besides, there is a 
 greater pressure of metal on the bottom or bed of a mould 
 than on the sides. The loam, when veins occur, has been 
 rather strong or tkich on the face of the bricks. No dry or 
 green sand castings are veined. No casting is ever con- 
 demned for being veined, ,but it does not looh tuell, and would 
 certainly not be fit for an exhibition, 
 
 /'.■SCALES 
 
 Are mostly found on loam, and sometimes on dry sand cast- 
 ings, but never on green sand. The blacking, and the way it 
 is put on, is the sole cause of scales. Blacking, to be good, 
 is made from oak charcoal, ground to powder as fine as flour. 
 A few years ago, some blacking makers introduced into their 
 blacking less expensive wood than oak, the result being very 
 unsatisfactory to moulders, owing to scales on their castings, 
 as, the wood being of a light nature, the charcoal did not 
 
IRON FOUNDING. 
 
 adliere to the mould. This adulteration gave rise to mucli 
 dissatisfaction, resulting in a patent blacking being invented, 
 which has not been in use many years. It is composed of 
 an article, being almost pure mineral carbon, which we under- 
 stand is made from shale out of gas retorts. It suits well, as 
 scales with this blacking seldom occur, unless when the clay 
 water is very weak, or carelessly put upon the mould. This 
 blacking is put into water which has been highly coloured 
 with common clay, the clay being for the purpose of causing 
 the blacking to adhere to the surface of the mould. Blacking 
 is put into the water until it attains the consistency of thick 
 paint. The clay water must not be too weak, as scales on the 
 casting may be the result ; besides, in this case, it is easily 
 brushed olf the mould when dry. Neither must the water be 
 too strong, as the blacking, after becoming dry, cracks all 
 over the mould, and is inclined to peel olf in many places like 
 a skin, and scales are sure to occur. 
 
 The blacking is put on with a common paint brush, or (as 
 in the case of diy sand) with a swab. It is laid on ordinary 
 castings until the mould has a coat equal to the thickness of 
 heavy paper ; but where the metal is very heavy, it is all the 
 better with a thicker coating. Care should be taken i;i 
 blacking a mould not to put on too much at a time, and not 
 to come over the joinings of the blacking, and it should not 
 be applied when the mould is very hot. 
 
 Scales are troublesome to the cleaner, as, being so thin, 
 they are not easily chipped off ; and when they are chipped 
 off, the casting has any thing but a nice appearance. 
 
 In some foundries all the moulds are sleeked with tools for 
 the purpose during the process of blacking, and scales will be 
 caused through sleeking too hard, or continuing the sleeking 
 after the blacking is nearly dried on, which is done by the 
 moulder for the purpose of trying to make his casting look 
 nice and have a smooth skin. Too hard sleeking is apt to 
 
40 
 
 A TEE AT IS E ON 
 
 slacken the liold of the blacking, especially when the mould 
 is very dry, or a little warm. 
 
 The patent blacking has a great advantage over tJie lest 
 charcoal, as it is scarcely ever burnt off by the flame catching 
 the mould at the time of drying, which was no unusual thing 
 when the charcoal blacking was in use, when it would have 
 to be blackened over again. 
 
 COLD SHOT CASTINGS 
 
 Are produced by three causes. (1) The mould being filled 
 too slowly. (2) The metal being too dull to suit the kind of 
 casting required. (3) The metal being poor. Cold shot is 
 another word for a bad weld — a refusal of the metal to amal- 
 gamate at the place of meeting in the mould. The green 
 sand moulder has more reason to fear this than the dry sand 
 or loam moulder. His mould being cold and damp, if the 
 metal is admitted too slowly it will rise lazil}^ up the sides, 
 getting thicker until it comes to the place of meeting, where 
 it will fail to join, as shewn in the section of a column or 
 pipe. Figure No. 8. 
 
 Fig. 8. 
 
 We are supposing the pipe to be cast horizontally, and the 
 metal to be admitted at the end of the mould, as many are 
 run in this way. A pipe of this kind for either steam or 
 water would be of no use, and a column to support any 
 weight would be very much weaker, than if sound on the top. 
 
IRON FOUXDING. 
 
 Too dull metal, even when run into the mould with proper 
 speed, will shew exactly the same fault. < 
 
 Poor iron — pig iron of inferior brands mixed with rlirty lahfcL 
 scrap, possibly some of it burnt, old fire bars, &c., will brin^'' 
 metal out of the cupola with no life. Be it ever so hot, it will 
 not run, it seems dead, and has scum or skin on the top of it 
 like stagnant water. Whatever mould this metal is put into, 
 unless put in very quickly, or the casting is of an unusual 
 thickness, it will produce a casting that is liable to be cold 
 shot. Even a difficulty is found in getting common furnace 
 bars to run with metal of this description. 
 
 Sulphur, silicon, manganese, and other impurities, are 
 found in the best of metal, but in this j)oor iron they seem to 
 be present in a greater degree, causing this skin and prevent- 
 ing amalgamation. In boiler plates something like this is 
 sometimes found, which is termed lamination." 
 
 MENDING OE BUENING CASTINGS. 
 
 When any -psLvt of a casting has been broken off, such 
 as a flange or a snug, or a blown hole has appeared, the 
 moulder considers whether he can mend this without injuring 
 the casting. Mending, so as to insure success, will depend 
 wholly upon what part of the casting requires it. The 
 formation of the casting has also to be considered, as well 
 as the kind of metal that has been used ; and herein lies the 
 danger of burning or mending. It is not every casting 
 that ^vill stand a portion of it being brought to a melting 
 heat without splitting in some adjacent part ; it depends 
 almost wholly upon the formation of the casting. 
 
 Mending at the extremities of a casting of almost any shape 
 is generally safe, but at the middle parts seldom a success. la 
 our opinion, mending a casting by burning a piece on should 
 never be resorted to,' unless it cannot be- mended otherwise,. 
 
42 
 
 A TREATISE ON 
 
 as it is often a forlorn hope. Wlien tlie casting is a bad 
 one, owing to a fracture, blown part, &c., it cannot be made 
 worse by burning, whicli may as well be resorted to. Burn- 
 ing or mending a casting can only be done once on the same 
 place ; hence the necessity of taking every precaution before 
 beginning. 
 
 When a casting has been broken, and mending the part 
 resolved on, it is best to use the piece broken off when it can 
 be had, and if it cannot, then one exactly the same pattern 
 should be cast. 
 
 The broken piece being laid to the casting in its place, 
 pieces of dried loam (called cakes) are then fitted about the 
 part, leaving about half an inch of space all along the frac- 
 ture exposed ; these cakes to be two or three inches higher 
 than the broken part, so that all the dirt and scum may float 
 to the top, and clear of the fracture. Cakes of loam are also 
 made to cover the bottom part, to prevent the metal from 
 running right through during the mending. The broken 
 part should then be surrounded with a fire until it becomes 
 red hot, the dried loam cakes bemg removed before the fire is 
 applied. 
 
 The portion of the casting to be mended, as well as the 
 piece to be burned on, being now red hot — good hot metal in 
 readiness — the fire smartly taken away — the loam cakes and 
 the broken part put back in their proper places — pieces 
 of iron ready at hand to secure them there, — the metal is then 
 run along the fracture until the casting and broken piece are 
 thoroughly fused together. This will be easily known by 
 travelling the point of a quarter or three-eighths iron rod 
 bjBtween the two. When the point of the rod touches the 
 bottom cake of dried loam, and nothing is felt but liquid iron, 
 the mend is complete. 
 
 Many castings stand the fire, but give way during the time 
 the metal is being poured on the fracture. After the mend 
 
IRON FOUNDING, 
 
 43 
 
 lias quite set, it should be covered over Tvith hot metal, and 
 not again touched until the whole is quite cold. The hot 
 metal used to cover it is generally that which was used in the 
 mending, broken into suitable pieces. 
 
 Again, some castings rend in the cooling. The softest of 
 iron No.' 1 should be used for a fracture, as it does not pro- 
 duce the greasy scum which comes from No. 3, and it also 
 penetrates quicker into the fracture, and is much easier 
 chipped. 
 
 The importance of mending a broken casting when red hot 
 is obvious, as it requires less metal to be poured on the break 
 than if the parts were black. Moreover, when the parts are 
 black, the metal when poured seems to glide off, as if the 
 broken part had been oiled or greased. The oil and tar from 
 the coal cause this to be the case ; and when the fire is made 
 with gas coke, the sulphur from it also produces the same 
 effect. 
 
 The metal for burning should be all in one ladle, it does 
 not answer when a second has to be used, as the mend is sure 
 to he dirty ; the refuse or slag," as it is commonly termed, 
 from the last of the first ladle being liable to lodge in some 
 part of the half -mended fracture. 
 
 When a large casting has to be mended, it is best to put it 
 the night previous into the stove, which should be cold when 
 it is first put in, then fire well up till the next day. When it 
 is taken out of the stove, put the fire at once on the place 
 to be mended, and when that is done lose no time in return- 
 ing it back again to the hot stove. In this way the whole 
 casting expands gradually, and, cooling down with the stove, 
 it contracts slowly. 
 
 When a casting has been imperfectly mended, and has been 
 done again, it will be liable to crack two or three inches from 
 the fracture, the reason of this being that the metal two 
 inches back from the fracture has lost all its elasticity, in 
 
'44 
 
 A TREATISE ON 
 
 short it is calcined — it has become like the top or rather 
 middle part of a furnace bar that has long been in use. The 
 two inches of the casting next the fracture are dead ; and 
 even should the second mend be a complete weld, if that part 
 is struck lightly with a hammer it will be very liable to 
 break two or three inches from the original fracture ; hence, 
 if a mend is not properly done on the first trial, you cannot go 
 hack to it again with success. The best thing to be done on a 
 second bui-n being resolved on is to cut three inches off 
 next the fracture, and in this way you come to good metal 
 again. 
 
 It may be fairly questioned — Is a burn as good as if the 
 casting had never been burnt ? "We at once answer, 
 (assuming the mend has been properly done, and there are no 
 symptoms of a crack on any part of the casting,) it is 
 equally as good as if no burn had taken place. For example, 
 we have known the tooth of a spur-wheel burned on to stand, 
 while some of the others gave way. Again, we have burned 
 a large piece on propeller blades, which have come back to 
 us again broken on the same blade, but never near the burn. 
 Therefore, from carefully watching the results of mending 
 castings, our impression is that the mend when properly 
 done is equal in strength to the rest of the casting. 
 
 It may again be asked — Would the burning have an evil 
 tendency on any other part of the casting, even a considerable 
 distance from the mend, and thus when the working strain 
 is put upon the casting cause that part to give way ? In 
 answer, we would say that it may and even does take place in 
 castings of a certain structure, such as bed-plates, conden- 
 sers, cylinders, girders, &c., where it is difficult to determine 
 on what part of the casting an undue strain may take place, 
 owing to a portion of it being made to a melting heat, cast 
 iron being of such a nature that it may be on the point of 
 flying and no one he aware of it ; but in plain castings, (and 
 
IRON FOUNDING. 
 
 45 
 
 especially when the mend is at the extremities,) we scarcely 
 think that burning has any vital effect upon the other parts. 
 
 When a mould has been cast, and an irruption takes place, 
 however slight, if the moulder is sure that metal has been 
 vomited out, it is well to take the top part of the mould off to 
 see the casting. The hollow blown places can then be quickly 
 and safely burned, the casting being in a bright red state. 
 Sometimes a mould will blow and vomit metal out for a con- 
 siderable time, and then after it has relieved itself of the 
 gases it will take back quietly all the required metal, in 
 which case the casting is seldom blown. In other cases a 
 mould will blow violently for some time, and as far as can be 
 seen not take any metal back, and, on the top part being taken 
 off will shew no symptoms of requiring to be burned ; but 
 when this does occur the soft parts of the casting are found 
 out when it is too lato to burn it, and most likely on parts 
 where it would be foolish and impracticable to try it. 
 
 Blisters or shells on a casting are easily mended when they 
 appear after being recently cast. They are generallj' to be 
 found on green-sand castings, and are caused through hard 
 rananing of the top part, and the want of the free use of the 
 vent- wire. They are seldom above a quarter of an inch deep, 
 two or three inches in length, and an inch broad, and very 
 often castings are condemned on account of their presence. 
 
 HAMMING GEEEN SAND OE DEY SAND. 
 
 Not a great deal can be said upon the above. Both kinds 
 of sand are rammed nearly in the same manner. Two kinds 
 of rammers are used for both green sand and dry sand, one 
 being called a small or pin rammer, the other a dog or flat 
 ranmier. The first is wholly made of iron rod, three quarters 
 of an inch round and fom^ and a half or five feet in length, 
 with a flat part at the end two and a half inches broad, and 
 
 £ 
 
40 
 
 A TREATISE ON 
 
 the same thickness as the rod. To be able to handle this 
 rammer properly is of great importance to the sand moulder ; 
 it is to liim what the hammer is to the smith, or the hammer and 
 chisel to the engineer. This rammer is used for ramming the 
 sand that lies close to the pattern, which is termed small or pin 
 ramming. 
 
 The flat or dog rammer is used for the intervening space 
 between the small ramming and the firm ground. It is a rod 
 of iron exactly the same as the pin rammer, with the excep- 
 tion that on the point of the rod is cast a piece of flat iron, 
 5 in. X 3 J in. X 1 inch ; hence its name. For pits and places 
 where much ramming is required, wood is substituted instead 
 of the three-quarter-inch rod iron, and is inserted into a 
 wrought iron socket, the point being a round or flat -piece of 
 cast iron. 
 
 Eamming wholly depends upon the nature of the work the 
 moulder ma,y be em2:)loyed upon. Light castings, such as 
 grate metal, balcony railings, balustrades, &c., require quite 
 different ramming from those of heavy green sand, so much, 
 indeed, that a light green sand moulder makes but a very 
 indifferent hand at heavy work, and vice versa, the great 
 obstacle being the different amount of ramming required. 
 We mav sav here that there is no defined rule for ramming-, 
 the experience of the moulder in the class of work being his 
 only guide. Therefore, the question may be asked — Is ram- 
 ming a rule of thumb business ? We answer, Xo. It is true 
 that some jobs will stand more ramming than is absolutely 
 needful without doing harm, more especially in dry sand ; 
 but in the majority of cases it is not so with green sand. 
 Any casting rammed too hard is liable to be scabbed, and if 
 reri/ nard, it will cause the metal not to stay in the mould ; 
 besides, great difficulty would be experienced in drawing the 
 pattern. The ramming of a mould, then, is judged by expe- 
 rience. The lower parts of a mould are made considerably 
 
IRON FOUNDING. 47 
 
 : -^^^U 
 
 harder than those near the top, owing to the pressure of niet^^ 
 being greater at the bottom. A moukl shoukl be Jirni, nothing 
 more, and care shoukl be taken not to strike the pattern in 
 ramming, which is liable to produce a scab, as it causes the 
 sand to be too close on the face of the mould, and prevents the 
 gas from passing into the openings made by the vent wire. 
 Again, a mould may be rammed rather soft ; in which case, 
 especially if there is a deep flange, or deep parts in the 
 mould, the deep parts are sure to be swelled or strained, 
 and are made perhaps half an inch thicker than they should 
 be, besides being irregular and out of shape. A part or parts 
 of a mould not properly rammed is sure to turn out an ugly 
 casting, besides causing a deal of extra work after the pattern 
 is drawn. The moulder may try to rectify it to some extent 
 by firming up the soft places, but it rarely succeeds in being 
 so well done as when the mould is properly rammed when 
 the pattern is in the sand. 
 
 Dry sand will stand much more ramming than green sand, 
 and can always be made much firmer, the reason of this 
 being that the drying of the mould has an opening effect on 
 the sand, causing it to become more free in the pores by the 
 ■exclusion of the moisture. If a dr}' sand mould be filled 
 when it is not dry, or only partialis/ so, the metal would most 
 certainly not stay in the mould, and this would be wholly due 
 to the closeness of the mould. But the drying (for the reason 
 mentioned) produces an openness in the sand which allows 
 the gases to pass freely to the vents, and the metal lies quietly 
 and kindly in the mould. Thus great freedom can be used 
 in ramming dry sand, which cannot be made too hard, that is, 
 •of course, compatibly with the drawing out of the pattern. 
 
 With green sand the same liberty cannot be taken without 
 causing bad results. Should the top part of a mould that has 
 a plain flat surface be too hard rammed, and not extra well 
 vented, the casting will present an appearance of being cold 
 
A TREATISE OX 
 
 shot, and in some instances will be blistered, although, the 
 metal Tvas in good condition. 
 
 ■ "\Ye may close this part on ramming with the moulder's 
 motto — Eam well, but vent well, as the venting is an antidote- 
 to a mould too hard ratnmed. 
 
 HIXTS OX PATTEEXS. 
 
 A properly-made pattern is of vital importance to the 
 moulder, and not only to him, but to the parties who have to 
 do with the casting after it leaves the moulder's hands. A 
 casting that is the exact shape and form of the pattern will 
 give less trouble to those who have to work with it than 'when 
 it has to a certain extent lost its shape and form. And how 
 is this to be attained V Simply by making the pattern so that 
 it may freely leave the sand. In jobbing foundries too little 
 attention is ^^aid to this object, hence the pattern suffers by 
 the moidder having to rap it severely to slacken its hold of 
 the sand. A pattern has often been broken to pieces in 
 di-awing it out of the mould, and a stranger to look at it 
 might allege downright carelessness on the part of the 
 moulder : but in every case he is not to blame. The j)attern 
 must be started in the sand before trying to draw it ; and if 
 proper provision lias not been made by the pattern maker in 
 the shape of places set apart for rapj^ing and a certain 
 amount of taper, also made of seasoned Avood, the pattern 
 will be sure to suffer, and the mould also. 
 
 In foundries where certain classes of work are done by 
 machinery, such as sewing machine castings, railway chairs, 
 telegr^iph posts, mill machinery. kQ., all the patterns are got 
 up regardless of expense. And why ? Eecause the pattern 
 must leave the sand without a grain being disturbed, and 
 without it being started before being drawn. Xothing 
 less would do. Balcony railings, balustrades, fancy gate 
 
I Fx ON FOUNDING. 
 
 work, grate metals, &c., must also leave the sand perfectly 
 undisturbed. 
 
 It might be said here that such a class of work is quitQ 
 different from jobbing work, and that it would not pay to get 
 up jobbing patterns like the class just mentioned ; but it 
 would be just as eas}^ to get up patterns to mould right by as it 
 is to make them so that the}- are a trouble to the moulder. 
 
 In some foundries great trouble and expense are experi- 
 enced through ill got-up patterns, the pattern shop going 
 upon the principle of economy in their department, which is 
 quite commendable so long as it does not cause undue 
 expense in the foundry ; otherwise the principle becomes very 
 reprehensible. 
 
 A pattern maker should have some knowledge of moulding, 
 which is indispensable on his part ; and so long as he keeps 
 that knowledge subservient to the moulder all goes well ; 
 but when he thinks he knows more than the moulder, ichich 
 too often happens, work between the two does not go smoothly. 
 They are closely allied in their work, and, such being the 
 case, it becomes them to work to each other's hands as much 
 as possible. Tlie pattern maker can save the moulder a great 
 deal of trouble by ver}- little exertion on his part, and so with 
 the moulder. It becomes them, therefore, to give and take, 
 neither to be too exacting. Should one know every thing, 
 and act upon the principle that the other knows little or 
 nothing, no good can ever come of it, as the ignored one is 
 sure to suffer through working at a disadvantage. 
 
 The pattern maker should be often in the foundry-, as it is 
 there he will gain experience, and will see that all castings 
 do not contract one-tenth of an inch to the foot, as he was 
 taught at the bench. The amount of contraction will in a 
 great measure be according to the shape and form of the 
 easting. 
 
 Again, loam castings, as a rule, do not contract so much as 
 
50 
 
 A TREATISE ON 
 
 sand castings, partly owing to the material that the loam 
 mould is composed of offering a greater resistance to contrac- 
 tion than that which sand offers, and partly because all loam 
 moulds yield a little to the mould exjianding after being just 
 filled. In large loam castings this occurs to a greater extent 
 than in small or light loam work. 
 
 The pattern maker by being often in the foundry will see 
 how his work comes out of the sand, and will be able to avail 
 himself of any suggestions that the moulder may have to offer 
 for their mutual benefit and the interest of their employer, 
 and in this way hard work will be made easy. 
 
 The moulder on his part should take great care of his 
 pattern, and nothing is more conducive to that than the know- 
 ledge that his pattern is well made for moulding. Patterns 
 that are intended to be moulded in loam should be made of 
 as little wood as possible, compatibly with sufficient strength. 
 The pattern maker should consult the moulder before he 
 begins to make his pattern as to which way it would be best 
 to mould it, and on both coming to an understanding much 
 trouble will be avoided. The moulder in this way becomes 
 conversant with what the different parts of the casting are sup- 
 posed to do according to the designer's idea. 
 
 AVe will close these hints on patterns for the present, as we 
 may have to refer to them again in describing the three 
 branches of moulding. Sufficient has been said to enable the 
 reader to understand how essential it is for the moulder and 
 the pattern maker to work together. 
 
 EUNNIXG METAL INTO MOULDS, AND THE USE 
 OF FLO'EES OE GATES. 
 
 AVe cannot think of a more important question to the 
 moulder after venting than — How will you run that casting ? 
 And after that question is answered there is another — "W^at 
 
IRON FOUXDING. 
 
 51 
 
 size of runners, and how many do you propose ? From the 
 smallest sheave of one pound weight, or a fancy little 
 ornament, up to a casting of sixty tons, the choice of a place 
 for running the metal in is of ^reat importance. 
 
 A light job in green sand, or a heavy one in green sand or 
 loam, may be all that a first-class moulder could desire, and 
 yet the casting may be spoiled through being run badly ; and 
 this is done ( 1 ) by running too quickly, (2) too slowly, and 
 (3) by not running in the right place or j)laces, as we learnt 
 from running a little fancy ornament or sheave when we 
 were apprentices ; and also in running a sixty-ton casting 
 the same principle is involved. The choice of a place or 
 places to run in the metal will wholly depend upon the for- 
 mation or shape of the mould. Suppose we take a fancy 
 ornament, we examine it for the strongest place and one 
 where no obstruction is offered to the metal running into the 
 mould. The system of ways or gates is generally adojDted, 
 and made by joining four or five sprays or small runners 
 from the main one. These little branches should be opposite 
 a slight space in the mould, so that the metal has free course 
 to pass all over. The more sprays that are cut from the 
 main runner the less size they will need to be, and are of course 
 easier broken off the casting. A fruit plate could not be run 
 in this way, as the edges of the casting are so thin and frail 
 that no runner could be attached to them without a great risk 
 of breaking the casting in taking the spra3^s off ; hence a 
 fruit plate is run by the centre, because there is a flat roimd 
 space. Sometimes a flat and sometimes a round runner is 
 used, and one is as good as the other. In this way the metal 
 has free course to spread all over the intricacies of the mould. 
 Balcony railings are generally run with three and sometimes 
 four main runners, each having upwards of twelve little 
 sprays, as in the case of the small ornament. Balustrades 
 are generally run from the plain end or stalk. Water-runs 
 
62 
 
 A TREATISE ON 
 
 for houses are run from the top, the convex part being cast 
 up, and the runners (there are two) are about ten inches in 
 length and only a quarter of an inch wide at the joint, 
 tapering to three inches at the opening. This is what is 
 termed a plump runner or gate, so called because the metal 
 from the ladle falls or plumps at once into the mould. The 
 castings could not be run at the edge, being so thin. Pots 
 and kettles are cast exactly the same way, the runner only 
 being much shorter, say three inches. These runners are 
 made wide at the top, so as to enable the moulder to throw 
 in the metal at once. This class of work is a speciality, and 
 a good moulder at am'- other class of work would be very 
 imperfect at water-runs, pots, and kettles. Grate metarisall 
 run from the edge, with a great many sprays leading from 
 the main runner, care being taken to make these sprays half 
 the thickness of the casting, and in this way they are easily 
 broken off. A sheave presenting a thin edge all round can 
 be cast no other way than by a plump gate or runner. It is 
 placed at the side of the core in the centre, and a round pin 
 of wood is rammed up in the top part of the mould, thus 
 forming the runner. 
 
 Again, bevelled pinion wheels are run at the centre, and 
 not from the top, the metal being admitted through what is 
 called a worm-gate. The object in running a casting like 
 this in such a manner is to prevent the tender teeth from 
 being washed away by the metal, as would most certainly be 
 the case in a green sand mould were the metal admitted from 
 the top, as in the sheave. All small pinions of a fine pitch 
 are generally run in this manner ; but when the moulder has 
 no worm-runner he is obliged to run the metal from the top, 
 in which case the mould should be slightly dried to harden 
 the teeth, and in this way it enables the mould to stand the 
 metal better. If only one casting is wanted he should mould 
 two, as the risk is too great to depend upon one cast in this 
 
IRON FOUNDING. 
 
 manner turning out perfect. From these few modes of run- 
 ning small castings, it will be at once seen that everything 
 depends upon the shape of the casting wanted as to how and 
 where the metal should be admitted. 
 
 Ordinary sand work is generally run by the lowest place in 
 the mould, unless in the case of pipes, columns, &:c. A column 
 that has a top and base to be turned and polished should be 
 run in the centre of the casting, the metal just clearing the 
 sides of the core. The end or base of the column presents at 
 the first glance a better place to run it by, and in fact so it is 
 when the skin of the base is not to be broken. Some 
 moulders may think this strange, but a column run in the 
 centre will give a clean base and top, and when run by any 
 end will be dirty. The reason may be asked — Why is it so ? 
 We would say that the motion of the metal caused by the 
 runners playing down the base produces a kind of scum 
 faintly mixed with slag, and the good metal flowing under- 
 neath fills the other parts of the mould. This impurity rises 
 until it touches the top, where it remains. Nothing will be 
 seen on the rough casting to indicate any impurity, but the 
 latter will be seen on the skin being l)roken, more especially if 
 the metal used is dirty, and columns are often cast with any- 
 thing but good clean metal. 
 
 The question may here be very fairly put — Does no scum 
 or slight slag gather in the centre of the column when run 
 there, to cause a weakness in the casting ? We would say 
 not at all, as there is no place to retain any impurity, such as 
 the base or the top of the column offers. It is continually 
 .getting away, and consequently cannot gather as it does in 
 the base when run there. Were the column to be turned 
 all over round the locality of the gates it might be found 
 slightly dirty when the skin was broken, but no good moulder 
 would cast a colunm horizontally that had to be turned all over. 
 Our business at present, however, is with columns for ordinary 
 
54: 
 
 A TREATISE 
 
 purposes ; tliey may be cast horizontally, and tlie best way 
 is to run them at the centre, taking special care that the 
 metal does not strike the core, or scabs may be made. It is 
 safe and sure, with heavy green sand, to run at the lowest 
 part of the mould, because in this way the metal rises quietly 
 and kindly all over the mould, and thus in a great measure^ 
 prevents scabs. The number and size of the runners wholly 
 depend upon the job to be cast ; for instance, a machine bed 
 of the heaviest kind for planing may be cast with four run- 
 ners, two at each end. Another kind of casting, not a third 
 of the weight, may require six runners. The heavy machine 
 bed can admit with safety two large runners at each end, while 
 the other job perhaps could not be done with any other than 
 small ones, hence the need for more of them. The size of each 
 runner depends upon the thickness of metal it is attached to. 
 
 When a mould is run from the bottom the runners require 
 to be much larger than when it is run from the top. Moulders 
 sometimes make the mistake of furnishing a mould to be run 
 from the bottom with the same sized gates as would be used 
 if it were run in the ordinary way. The bottom runner or run- 
 ners should be one quarter larger than when the casting is run. 
 from the top, seeing that they have to press the whole weight of 
 the casting uj) when the mould is about filled. A mould so cast 
 will take the metal from the ladle at first with great speed, but 
 as it fills it will gradually take it slower and slower, until when 
 just about full the moulder will find that it is comparatively 
 slow. Green sand castings of a few hundredweight may be 
 and are run from the top with safety, as the metal has not far 
 to fall, but castings from ten hundredweight up to five or six 
 tons should be run from the bottom, that is, the lowest part, 
 care being taken to have the runners thinner than the thick- 
 ness of the metal, as they are less liable to scab the mould 
 when the metal is rushing in, and prevent the edges of the 
 casting from getting broken in separating the gates from it. 
 
IRON FOUNDING, 
 
 55 
 
 Figure 9 shews us exactly the formation of the bottom 
 gate. The vertical gate must be at a sufficient distance from 
 the mould to enable a strong body of sand to intervene be- 
 tween them. Many castings have been lost owing to the 
 pressure of the metal in the upright gate forcing in the sand 
 upon the mould. Eighteen inches are sufficient when the 
 sand is well supj)orted with irons. 
 
 Fig, 9. 
 
 It may be here asked — How do you get these runners out 
 before the metal is admitted ? The reply is simple : After 
 the pattern has been drawn, and when the mould is finished, 
 the square or rectangular-shaped one is drawn to the inside of 
 the mould, and the upright round one drawn upwards, both 
 being tapered to suit. 
 
 When a dry-sand mould is made with rotten rock and dried 
 loam, it can be run with comparative safety from the top, 
 especially when the mould has been thoroughly dried, the 
 nature of the material being well adapted to resist the fall of 
 
50 
 
 A TREATISE ON 
 
 the metal upon tlie bottom or surface of the mould. We say 
 with com2)arative safety," but in order to make the opera- 
 tion perfectly safe it is better that the mould should be 
 warm. 
 
 A dry-sand mould made with Erith sand is very different. 
 In this case, when the cast is run from the top and the mould 
 is cold it is invariably scabbed ; and when a moulder hnows 
 that he cannot close his piece of work during the time that 
 the heat is retained in the mould, he siiould make provision ^ 
 to admit the metal at the bottom of tlie mould. 
 
 When a mould is made of the last-described material, and 
 can be cast when the mould is hot, it can then with perfect 
 safety be run from the top, and the mstal may fall' any 
 height. 
 
 This sand seems to have a particular propensity to contract 
 damp after becoming cold. Every dried mould does so to a 
 certain extent, but this sand in particular becomes cold sooner, 
 and absorbs the damp more quickl}', than any other dried 
 8and of which we know. 
 
 Loam castings, or, as we might say, castings made in loam, 
 are invariably run from the top, except in sj)ecial cases, and 
 these cases occur when the metal cannot reach or fall wpon 
 the bottom of the mould as soon as it leaves the ladle. Some 
 part of the mould forming a projection, the metal falls upon 
 this fii'st, continually playing upon it until the under part of 
 the projection is filled. The best made loam, even though of 
 the best material, would be very liable to scab were the gates 
 leading the metal to fall upon a projection of the mould, 
 jnore especially if the mould were cold when the metal was 
 admitted. 
 
 The greatest number of loam moulds are run from the top. 
 Three reasons seem to establish the superiority of this method 
 over others. First, it can be performed with safety when 
 no part of the mould intervenes between where the metal is 
 
IRON FO US DING. 
 
 57 
 
 admitted at the inlet or gate and the bottom of the mould ; 
 second, it is better for any casting when the mould is run 
 from the top, since the highest parts of the casting are filled 
 with hotter and better iron than when the molten metal is^ 
 run from or at the bottom ; this of itself is calculated to give 
 the casting a sounder top than it would otherwise have ; and 
 third, the moulder can collect all his runners or gates more 
 compactly when he is forming his large gutter (commonly 
 termed head ") with sand, previous to casting, than he 
 possibly could have done had the casting been run from the 
 bottom. 
 
 Sometimes it happens in loam moulding that the formation 
 of the casting to be made will not admit of gates or runners 
 from the top being used in sufficient numbers or size to fill 
 the mould in proper time, or there may be no direct and clear 
 way for the metal to reach the bottom. When a case liko 
 this occurs the metal is run in at the bottom, possibly with 
 the assistance of a few gates at the top. 
 
 Propellers are better castings when run as high up as 
 possible on the boss. The top of the blades thus gets hotter 
 metal, rendering the edges clean and sharp. This is seldom 
 the case when the metal is admitted at or near the bottom of 
 the boss. 
 
 Cylinders require, more than any other loam castings, to 
 be run at the toj), as this -plan has the effect of giving the 
 casting a clean bore. The gates or runners should be all 
 round the barrel, the distance between eacli pair not exceed- 
 ing eighteen inches. Care must be taken to see that the 
 metal clears the outside and inside of the mould. 
 
 In casting very large moulds the moulder should take care 
 to have his running gates properly distributed for the good of 
 the casting, and yet not too scattered, as they have all to be 
 connected in a large gutter, and when they are needlessly 
 scattered in arrangement it will necessarily cause more metal 
 
A TREATISE ON 
 
 to be melted than is absolutely required, and really do no 
 good to the casting, wliile it will cause the workmen to have 
 extra labour in breaking up the heads. 
 
 A loam mould run at the top mai/ scab, but it only occurs 
 ivhen the material is bad, or has not been properly dried. 
 Loam too weak, too strong, or too muddy, is termed bad, and 
 when not properly dried it is either burnt, or retains a suspi- 
 cion of moisture. AVhen a mould is in either of these states 
 it will scab, no matter where it may have had the metal 
 admitted. Erith loam when burnt is much safer than iron- 
 sand loam. 
 
 THE MOULD FILLED TOO SLOWLY. 
 
 AYhen the moulder has decided on the place or places at 
 which to run his casting, his next care is to see that his run- 
 ners or gates are adequate in size and number to fill the 
 mould in proper time, so as to insure a sound casting. ^\Tien 
 he is moulding an ornament, say a fruit plate, and makes his 
 little s^^rays or runners from the main gate too small, or too 
 few, his work will be a failure. There will be a want in the 
 fruit plate here and there, the metal having been so slowly 
 admitted has been ^^dead" at different places of the mould, 
 refusing to travel — or rather not being able to travel — 
 through the little veins or channels in the sand. The same 
 thing happens with moulds for a balcony-, balustrade, pot, 
 kettle, and water-run ; the failure occurring even when the 
 metal is of the finest quality, and as hot as the fui-nace can 
 make it. Castings of an ordinary size in green-sand suffer 
 much when cast too slowly, no matter what their shape or 
 form may be. Some, of com^se, will suffer more than others, 
 such as spui' wheels, pulleys, lamp-posts, &c. Over-slowness 
 is also very injurious to heavy work done in green sand, if it 
 will not altogether, in many instances, be the means of prac- 
 tically destroying the cast. 
 
IRON FOUNDING. 
 
 When the mould has a large surface, and that oii^-tiLe^top, 
 and the surface is exposed too long to the great heat of the 
 metal during the slow process of filling the mould, there is 
 danger of a portion of the top part being drawn down ; and 
 even when the top part does stand good the casting on 
 the top Avill have an ugly a^opearance ; the edges will be round 
 and full of dirt ; cold shot will prevail all over the casting ; 
 and the latter will have but little chance of being looked 
 Tipon as worthy of the name. In the case of a loam mould 
 which has retained some of its heat, but in which the casting 
 has been done too slowly, the casting does not suffer to the 
 same extent as in the case of a sand mould, the reason being 
 that owing to the warmth of the mould the metal retains its 
 lively condition much longer than it does in the cold green- 
 sand. 
 
 A loam casting, in order to shew cold shot, must have been 
 east very slowly indeed, or the metal must have been very 
 inferior and dull Avhilst in the ladle. The parts where it is 
 most likely to be faulty, for a large loam casting, will bo in 
 the different webs or plates that may intervene between the 
 bottom and the top of the mould, and in some j)laces where it 
 may not be easy to see it, especially where there are 
 ehaplets. The metal rolls lazily up the sides of the mould, 
 earrying along with it dust and particles from the mould, until 
 it reaches the top of the first core, over which it slowly flows, 
 and meeting in the centre, possibly no amalgamation is formed 
 at the proper place of juncture, or if it does, the amalgama- 
 tion is onl}^ a very imperfect one. 
 
 When ehaplets are in a web of metal the metal will not 
 elose so keenl}^ and completely round them as it ought to do. 
 Water or steam may pass between the ehaplets and the metal, 
 and in this way the mould is filled until the metal reaches the 
 top. The casting thus produced may not present a very 
 faulty appearance on the top, but other parts of it will 
 
CO 
 
 A TREATISE ON 
 
 probably be mucli less satisfactory than its superficial area. 
 Take for example a casting of tlie form of 
 
 Fig. 10. 
 
 — ^ 
 
 i 
 
 I 
 
 I 
 
 I 
 
 i 
 
 Supposing tlie moulder to bare made bis gates or runners 
 too small, and to bare placed no runner on the bigbest part, 
 tbe metal at tlie same time being ratber dull. In tbis case 
 tbe part marked < on tbe figure would be apt to sbew 
 wbat at first sigbt would seem to be a crack, but wbicb, on 
 closer inspection, would be seen to be — not a crack, but — cold 
 sbot. Tbe reason would be tbat tbe metal bad sligbtly 
 paused at tbis point in its uj)ward progress during tbe time 
 
IRON FOUNDING. 
 
 01 
 
 the plate was getting filled, tlie slight stoppage being enough, 
 to produce a strong film or skin at that particular place, and 
 thus cause a parting, as it were, between it and the metal 
 above. Had a runner been here to keep the metal in agita- 
 tion during the filling of the plate no harm would probably 
 have supervened. 
 
 This illustration may help the reader to comprehend how 
 important it is to have the runners from the top and properly 
 distributed over the mould, as he may not always be sure of 
 getting hot iron to cast with, even apart from the contingency 
 of his mould having been run too slowly. A propeller is 
 sure to have an ugly look when it has not been properly 
 filled, the top edges of the blades appearing as if rats had 
 been eating them. A casting of this kind might likely be 
 condemned when the metal is not run with proper speed into 
 the mould. A piston (when large) which has been cast too 
 slowly presents an ugly appearance on the top of the casting, 
 so that engineers do not care about having it. The casting 
 seems so unsound and ill-looking that they believe the steam 
 would very soon make a serious impression upon it. Such 
 would very probably be the case, as the casting would not 
 possess a hard skin, and would be wanting in that essential 
 element requisite to give it the sound surface so much 
 needed in a piston. 
 
 A cylinder cast too slowly with ordinary hot iron would be 
 very apt to be defective in the bore, especially if the metal 
 was not clean. The casting otherwise may appear first-class, 
 or it may shew threatening signs of cold shot on the top, but 
 not enough to call attention to the fault. If the metal be 
 veri/ hot, and at the same time clean, these qualities may save 
 the casting, even when the latter is produced slowly. But 
 very hot iron is not the rule in large castings, and we should 
 therefore say that the cylinder which has been cast too slowly 
 has a slender chance of turning out a clean bore. 
 
C2 
 
 A TREATISE ON 
 
 Dry sand castings fall under the same remarks as loam as 
 regards filling the moulds too slowly. 
 
 THE MOULD FILLED TOO QUICKLY. 
 
 This is an evil that the moulder should guard against 
 equally as much as against undue tardiness, since serious 
 consequences are apt to attend it as well as the other. There 
 are perl^^ps a few castings which msiy be excepted from this 
 observation, that is, they can scarcely be filled too quickly. 
 "We refer to such castings as those of runs for houses, pots, 
 pans, and several other castings connected with sanitary pur- 
 poses. These being so thin the metal has almost to be '(as it 
 were) thrown into the moidd, the moulding boxes being 
 properly secured so that no straining of the casting may take 
 place. In casting ornamental work, when the metal is rushed 
 in too quickly, in some instances the box may yield, and 
 slight fins of metal will be formed on the outer edges of the 
 casting, while the casting is webbed all over where the spaces 
 should be. In such cases the casting is said to be strained," 
 through the runners being too large. When the box does 
 not yield to the undue forcing in of the metal the casting 
 
 ill be liable to get broken in the process of detaching the 
 r.mners. 
 
 We may here mention, before going further, that the 
 terms gate" and '-runner" are not at all times s^monymous. 
 A gate (strictly speaking) conveys its own meaning, that is, 
 an entrance. The runners are supposed to be branches made 
 to lead aU over from the gate ; but moulders frequently 
 confound the one term with the other, or ignore one or the 
 other by using the term gate or runner indifferently. Eor 
 the future, then, we shall speak of the gate as the entrance, 
 the place where the metal enters first, and the runners as 
 merely connecting the casting or mould with the gate. 
 
IRON BOUNDING. 
 
 All kinds of ornamental and grate metal are cast much 
 more quickly than ordinary green-sand work, but it is quite 
 possible to over-do it, and for the casting to become slightly 
 strained, causing a deal of extra work to the dressers in chip- 
 ping and filing off the fins. This is the only evil that this 
 class of work suffers from when cast too quickly. But in 
 foundries where they cast nothing else but this kind of work 
 every casting is run at the proper speed. 
 
 In ordinary green-sand castings it is essential that the 
 moulds should not bo filled too quickly, for two reasons ; 
 first, the mould does not get sufficic^it time to expel the gas 
 into the vent made by the vent-wire, especially where the 
 mould contains a dried core, both mould and core in that case 
 being liable to scab ; second, unless the box be carefully 
 weighted or clamped the metal will be apt to out at' the 
 edges, and in this way fill up the vents. Sometimes the 
 metal gets into the vent of the dried core, and when that 
 takes place the casting is a scrap, as the metal will then not 
 lie at peace in the 7nould. 
 
 Metal which has been rushed too quickly into a large green 
 sand m.ould covered with a box fifty hundredweight in weiglit, 
 and say thirty hundredweight of sand, and seren tons weight 
 on the box, will lift the whole with great ease. We do not 
 say that it is the metal alone which does this ; the efforts of 
 the air to find an exit have more to do with it than the metal, 
 although the primary cause is doubtless the too sudden 
 admission of the metal into the mould. When this takes 
 place with a large green sand casting the results are often 
 very serious. A drj^-sand mould, and also a loam mould, are 
 always bound with clamps diiring the process of casting ; and 
 the flow gates are kept open in both, thus enabling the air 
 that is in the mould to find a ready exit, and in this 
 way lessening the chances of the mould straining. The flow- 
 gates on the green-sand mould are kept closed until the metal 
 
04 
 
 A TREATISE ON 
 
 touclies the top part of tlie mould. Were they kept open, as 
 ill the case of the loam or dry-sand mould, the air rushing 
 out would be liable to disturb the part of the mould nearest 
 the flow-gate, and thus create a scab. The flow-gate is there- 
 fore kept closed with a piece of clay, and a light weight of 
 a few pounds resting on the clay until the mould is filled, 
 the atmospheric air finding its way out through the natural 
 interstices of the sand and between the joints of the box. 
 
 When a loam or diy-sand mould is too quickly filled a 
 violent bubbling takes place in the flow-gates, caused not so 
 much from any gas that the mould may generate as by the 
 quick expulsion of the atmospheric air. This can easily be 
 seen in casting from any dried mould that has no cores in it. 
 When cores are in the mould the bubbling is apt to take the 
 form of blowing, which may be described as violent bubbling. 
 When the metal is in a hot and lively state no harm will 
 ensue, or at all events only in rare cases, as the bubbling soon 
 ceases, and the metal immediately falls back into its proper 
 position. But when the metal is dull, and has little or no 
 life in it, the flow- gate, at the first admission of metal, may 
 set, and thus cause a hole or blown part in the casting 
 beneath the gate. Had the mould not been run so quickly 
 no harm would have occurred to the casting although the 
 iron had been a little dull. 
 
 It is of great importance to notice that castings, in order to 
 be turned, bored, or polished and planed, " should not be filled 
 too quicldy, especially large castings, owing to the difiiculty 
 of keeping all the gates well supplied with molten metal. 
 The gates are all connected by what is termed a *^head,"' 
 which is simply formed of sand, and to convey its purpose 
 more plainly we might call it a large gutter, nine or ten 
 inches deep by seven or eight inches broad. This head or 
 gutter is again connected with a basin of wide capacity, say 
 three feet square, sometimes made in sand or in loam, but the- 
 
IRON FOUNDING. 
 
 05 
 
 latter is preferable. The basin receives the metal from the 
 ladle to fill the head, the latter in turn filling the gates. 
 This head, then, when the moulder begins to cast, nmst he 
 kept full, to enable all the dirt and slag to float on the top, so 
 that nothing but clean metal shall enter the mould. The 
 moulder who is filling a large casting should have a firm 
 hand and a quick eye when he handles the ladle, in order to 
 detect every movement indicating how the mould is receiving 
 the metal. But when the gates are too large, and the head 
 cannot be kept full, what takes place ? Eefuse and dirt from 
 the head pass into the mould ; and, supposing the casting to 
 be a cylinder, the chances ai^e that it turns out to be bad in 
 the bore. This is often the case. The mould may be all 
 that can be desired, but, as we have endeavoured to shew, it 
 may be spoiled in its last stage by the undue size of the 
 gates. 
 
 The question may here be asked — Is there no rule — no 
 defined rule — for running castings ? AVe say at once there is 
 not. The size and number of runners or gates must depend 
 upon circumstances, viz. — the state of the metal, whether run 
 from the top or bottom, the formation of the casting, the 
 particular object for which the casting may be intended, and 
 many other things that moulders have to contend with. The 
 right way of working, and the right speed at which to cast a 
 mould, are matters of vital importance to the moulder, and 
 can only be thoroughly attained through experience. 
 
 THE USE OF FLOW-GATES. 
 
 As the moulder has gates and runners to admit the metal 
 into the mould, so he has gates to let it out when the mould 
 is full. These are technically termed ^'flow-gates,'' as the 
 metal flows into them. 
 
 Moulders engaged in light work do not use flow-gates, as 
 
OG 
 
 A TREATISE ON 
 
 they TTOiild serve no purpose for such AVork. Ordinary green- 
 sand workers use them according as the job in hand may 
 require to keep the casting from straining. For instance, in 
 the case of a plate four feet by five, of any thickness, flow- 
 gates would be used, as the relief which the metal experiences 
 in passing up the outlet considerably lessens the lift upon 
 the'bcx, besides relieving the mould from air. In sand work 
 these flovr gates may be put on the casting, or the}^ may be 
 made exactly the same as the running gates, according as the 
 moulder may see necessary. 
 
 Flow -gates are in use for three purppses, viz., to relieve 
 the mould from atmospheric air, to feed heavy parts of a 
 casting, and to shew the moulder at once when the mould is 
 filled. All kinds of metal, when in a liquid state an.d in a 
 heavy mass, are sure to subside, or, as the moulders term it, 
 
 draw" after the mould is filled. In order to obviate this ag^ 
 much as possible the flow gates are put upon the thick parts 
 of ca5,tings, and according to the thickness of the part so 
 should the size of the fiow'er be, that such parts may be fed 
 with metal during the time the casting is gradually becoming 
 set. Eod-irons, from a quarter up to three quarters of an 
 inch in thickness, as the case may be, are used for flow-gates. 
 When the mould is filled the moulder takes one of these rods, 
 thrusts it into the gate, and satisfies himseK that it is actually 
 in the casting. He then works the rod up and down, in order 
 to prevent the metal in the gate from setting. The casting, 
 gradually draws away the metal from the gate, the supply 
 being continually kept up with hand-ladles until at last the 
 casting becomes set in the place where he is feeding ; he 
 then gradurclly works up the rod as he feels the hardening 
 process going on, until it is at last out of the cast. The 
 feeding is then complete. 
 
 AVe may observe here that we are, as a rule, opposed to the 
 plaii of feeding castings, unless in cases where it is abso- 
 
IRON FOUNDING. 
 
 07 
 
 lutely necessary, such, as the following : — Anvil blocks, sugar- 
 mill rollers, extra heavy flanges on large castings, propellers,' 
 and in cases when a casting may be blowing, &c. Some 
 moulders are too fond of using the feeding rod in every 
 casting ; but we have known more harm occur from the inju- 
 dicious application of the feeding process than we have ever 
 known good to result from it. Twenty years ago every 
 cylinder that was cast had a rod passed in at every gate, the 
 number sometimes reaching sixteen or twenty in a large 
 casting. Strangers who came to see the cast on a dark night, 
 and in a darker shop, would not have missed the feeding 
 process for a great deal ; they thought it the best of the 
 whole thing. To see upwards of sixteen men, with blackened 
 faces, surrounded by the lurid lights coming from the vents 
 at the end of the pipes, the red-hot metal l3'ing at their feet 
 in the head, and each man working his rod up and down, 
 was a sight that remained long in the memory of the visitor. 
 Feeding cylinders, as well as many other kinds of casting in 
 which the plan was adopted, are now things of the jDast. 
 
 AVhen the moulder is obliged to feed his casting, it ought 
 to be rightly done, that is, he should have the flow-gate of 
 suflicient size, so that he shall have no trouble in keeping it 
 open ; and the rod should never penetrate further into the 
 mould than two or three inches. 
 
 We remember the case of a water-press cylinder being cast 
 bottom up, which was five tons in weight, seven inches thick 
 on the sides, and twelve inches on the top of the core. It was 
 fed for three quarters of an hour, and when put to use it 
 would not hold water. "When filled at night it was found to 
 be emj)ty in the morning. The reason of this was that the 
 feeding rod had been kept touching (or very near) the core 
 all the time of feeding, and that when the end of the rod was 
 withdrawn the metal had not sufficient life left in it to 
 thoroughly close the space left by the rod. On the flow-gate 
 
68 
 
 A TREATISE ON 
 
 being taken off the casting, a wound could be seen in the 
 centre, as if a knife bad made it, through which the water 
 found its way out. It would have been a better casting had 
 a rod not been used. If the mouth of the flow-gate had 
 been merely kept open, and a little hot iron occasionally 
 poured into the gate, there would have been no fear of the 
 casting not turning out a sound one. Those castings are now 
 cast bottom down. It was this bad use of the feeding rod 
 which stopped cylinders from being fed ; because in many 
 instances when they were bored, the track of every feeding 
 rod could be traced, the parts where they had been being 
 quite spong}^ 
 
 AVhen any portion of a casting has to be turned or planed, 
 and that part to do a deal of work, it is not advisable to have 
 a flow-gate there, as the part where the flow- gate has been is 
 sure to be much softer (and, if it has been fed, spongy) than 
 the surrounding parts. For example, not a few oscillating 
 cylinders have been condemned owing to a spongy part 
 appearing on the trunnion. The moulder, in his endeavours 
 to make that heavy part of the casting sound and clean, put^ 
 a large flow-gate on the top of the trunnion, and in this way 
 spoils his casting. Cylinders of this description have been 
 cast with large flow-gates on the trunnions, been fed, and 
 have turned out badly. They have been cast with flow-gates, 
 but no feeding, and have also been bad. It may here be 
 asked — Then why put flow-gates there at all ? Would it not 
 be better to dispense with flow-gates altogether, seeing that 
 the trunnion is placed so far down the casting, is subject to a 
 great pressure of metal, and therefore conducive to the sound- 
 ness of that part, although it has an extra thickness ? We 
 should say — Yes, that is quite true, you have exactly ex- 
 plained the reasons why a flow-gate should not be there ; 
 but the engineers who have ordered the cylinders desire to 
 have a flow-gate. It is their idea. And such has been the 
 
IRON FOUNDING. 
 
 09 
 
 case. An engineer, who occupies a high position in his pro- 
 fession, wanted a propeller made and cast from re-melted 
 iron of his own mixing. So careful was he of his mixture 
 that he would not trust the moulder, but sent his own man 
 with strict injunctions to tell the moulder to put a great many 
 flow-gates near the top edge of the blade. The moulder 
 demurred to this, not so much on account of the extra trouble, 
 but because of the absolute uselessness of the injunction. In 
 due time the engineer came to the foundry himself, and 
 demanded to know why the moulder refused to put the flow- 
 gates on the blades of his propeller, so as to take away the 
 dirty metal from the leading edge. The moulder informed him 
 that owing to the construction of the propeller, and the manner 
 in which it was cast, the top of the blades would be as clean as 
 the bottom, because of its wedge-like form, and that putting 
 flow-gates on the place would tend to bring about the very 
 thing which he (the engineer) wished to avoid, viz, the eating 
 away of that portion of the blade by the water, owing to the 
 skin of the casting being broken. The engineer then desired 
 to know how it was that one foundry could supply a propeller 
 that would last much longer before shewing signs of decay 
 on the blades than another foundry could, if it were not that 
 the one had better metal and was cleaner on the blades than 
 the other. The moulder endeavoured to explain that there 
 might have been some difference in the pitch of the propellers, 
 but the engineer would not be convinced, he said he knew 
 better, and intimated that the moulder did not know very 
 much. It is to bo hoped that the moulder took it all in good 
 part, as he may have learned before this time that an engi- 
 neer's opinion of moulders is, as a rule, not of the highest 
 order. 
 
 Flow-gates on the blade of a propeller can do no good, 
 except that they may ease the strain of the metal when the 
 mould is nearly filled, as in the case of the plate described in 
 
70 
 
 A TREATISE ON 
 
 tlie green-sand mould ; but breaking the skin of any easting, 
 as a flow-gate or gates \vQuld do, tliat is subject to the action 
 of water is to be deprecated. Flow-gates on a propeller 
 should, like any other casting, be put on the right place, 
 which is as near as possible on the top of the boss and above 
 the blade where the thickest part of the metal is. 
 
 Some moulders imagine that the plan of having a great 
 many ilow-gates on a surface that is to be planed or turned 
 (not a working part) makes a nice clean casting. AYe believe 
 that it does tend that way, but not quite so much as is per- 
 haps generally auj^posed, The casting may be dirty between 
 all the gates, the clean spots shewing where the flow-gates^ 
 were. It is a better plan to allow a little more than the usual : 
 margin for planing and have a clean cast, a clean mould, and 
 metal in good condition in the ladle. We should say that 
 these precautions will produce a cleaner casting than having 
 flow-gates. 
 
 Hard metal is very apt to draw or subside. Some engi- 
 neers wish to have castings of a certain kind cast with hard 
 iron. Now, if the thickness of the metal be not uniform, and. 
 a heavy part or parts be in the casting, these places vrill be 
 liable to become drawn. AYith hard iron it may be in a very 
 unlikely place on the casting where the moulder could not 
 reach, even if feeding thi^ough a flow-gate could have done 
 any good. This probably would not have taken place with 
 ordinary metal. With hard metal the case is very different. 
 
 We dislike the plan of feeding except in cases where it 
 really cannot be avoided, because we are convinced that it is 
 seldom carried out properly. How often has a good mould 
 been spoiled through a moulder's heedlessness in pushing his 
 rod roughly into a mould and thus breaking a core, the metal 
 getting into a vent and blowing the top off the casting ! 
 How often has the rod, when of common iron, broken oif at 
 the j)lace where it entered the molten metal, and quietly slid 
 
IRON FO UNDING. 
 
 71 
 
 into the barrel of a cylinder, the moulder perhaps saj^i^tf^ 
 nothing about it until the bore disclosed its presence ! And 
 how often does a moulder keep his rod in the casting far too 
 long, not fully realizing the necessity of gradually and very 
 carefully working his rod out as the metal sets ! 
 
 Then, to avoid feeding, except in the case of such blocks 
 as we, have already mentioned, let the flow-gates be large 
 where the metal is heavy ; and when the mould is cast with 
 good iron these large flow-gates should remain long enough 
 in a liquid state to supply the casting, they will then both set 
 simultaneously. 
 
 On the ather hand, it must be admitted that there are some 
 castings which would be prejudiced by the imposition of extra 
 largo flow-gates, as the process of chipping the latter oft' 
 might endanger the integrity of the result. Sometimes a 
 casting may require to be run by two or three large gates, 
 such as liirge spur wheels, heavy pinions, &c. Such castings 
 being run at the centre, and that part being heavy, recourse 
 must be had to the device of feeding with the rod iron, as the 
 gates of themselves, although large for runners, could not 
 feed the casting. Again, in the case of a large cylinder, with 
 a heavy' face, having a flange three inches thick, a flow-gate 
 could scarcely be put on sufficiently large to feed the surface, 
 recourse must then be had to the rod ; but the moulder should 
 bear in mind that he is onli/ to keep the flow-gate open^ and not 
 to ram his rod twelve inches into the casting. When the 
 moulder finds himself obliged to feed his casting, his rod 
 should be made red hot previous to its being thrust into the 
 flow-gate, since a cold rod precipitates the settling of the iron 
 in the flow-gate. When flow-gates pass through a loam 
 plate care should be taken to have the hole in the plate made 
 larger than the intended flow-gate, so that some portion of 
 loam may intervene between the plate and the gates. Where 
 there is no loam, and the metal has to flow on to the bare 
 
72 
 
 A TREATISE ON 
 
 plate, the gate may set too soon to feed the casting ; "besides, 
 a strong gate may seriously interfere with the proper con- 
 tracting of the casting, not to speak of the trouble which is 
 apt to be experienced in taking the plate off when the casting 
 is cool. The same precaution should be observed with regard 
 to running gates ; and in green sand or dry sand an inch of 
 sand should be between the bars of the moulding box and 
 the flow-gates. 
 
 Flow-gates are always put upon the highest part of a 
 casting. We scarcely approve of them in any other position 
 unless they are two and a half inches in diameter, so as 
 to rise freely to the level of the head or highest gate. 
 Flow-gates are good when put upon the proper part of the 
 casting. As to their number the moulder may put on as 
 mau}^ as he thinks fit ; they will do no harm, and not much 
 good ; but simply have the effect of giving him a little more 
 labour in putting them there, and of causing more labour 
 to the cleaner in removing them from the casting. 
 
 LIGHT GREEN-SAND CASTING. 
 
 The phrase light castings in green-sand" might be more 
 appropriate than the above heading. We have chosen the 
 latter by preference simply because moulders are accustomed 
 to use it. 
 
 The sand to be used for light casting ought to be of a fine 
 and superior quality, besides having certain chemical pro- 
 perties which ma}' all be found in one kind of sand, or in a 
 mixture of two or three kinds. It should be close in the grain 
 and of a soft nature ; close in the grain, because little or no 
 vent is required to come from light castings, the heat of the 
 metal not being great enough to generate, or rather to ex- 
 pand, the gases contained in the sand. It should also be fine- 
 grained, as no tools can be applied to the moulds in order to 
 
IRON FOUNDING. 
 
 73 
 
 make them smooth. Were the sand open or coarse the cast- 
 ings wouki be rough. The moulds of light castings are cast 
 just as the pattern leaves them. The chemical properties 
 contained in sand are supposed to be alumina, silica, and 
 magnesia. Some sand may also contain a little lime. 
 
 Erith sand and Belfast sand possess all the qualities 
 which are requisite to make light and fine castings, each kind 
 being sufficient in itself without any other mixture. One 
 advantage — if it is an advantage — the Erith seems to possess 
 over the Belfast sand, namely, the mould can absorb a greater 
 quantity of water when swabbed without doing much harm 
 to the casting. 
 
 As the sand for light work is fine-grained, so has the coal- 
 dust to be of the finest, well ground, and passed through a 
 hair sieve, the quantity of coal-dust being determined b}^ the 
 nature of the castings required. Too much coal-dust makes 
 some castings blunt where they should be sharp, and also 
 more difficult to run. We have seen castings not run up and 
 made bad solely owing to there being too much coal-dust in 
 the sand. This coal-dust sand is termed ^' facing sand," as 
 it is sieved on the pattern, and forms the face of the mould. 
 It is kept apart from the ordinary sand employed to fill the 
 boxes. 
 
 Parting sand — so called because by it the moulding-box 
 when rammed up is separated from the pattern — when used 
 for light work must be very fine and of a quality that will 
 not take up moisture. It should bo free from clay or lime, 
 and the lighter it is in colour the better. Some foundries 
 prefer burnt Belfast sand, others fresh water sharp sand, 
 others the sand that has formed the bottoms of large ladles 
 after they have been used for a considerable time and have 
 been cleaned out, while some others choose burnt sand taken 
 from heavy sand castings. We prefer the first-mentioned 
 kind, or that which is to be had from the bottom of the ladle. 
 
74 
 
 A TREATISE ON 
 
 Light green-sand moulding may be classed under three 
 heads — (1) hollow work, (2) flat work, (3) .jobbing work. 
 Castings that fall under the name of hollow work are pots, 
 kettles, pans, water-runs, boilers, ovens, and such like 
 castings of a hollow form. Flat work includes grate metal, 
 castings for sanitary purposes, and balconies or balustrades 
 to form railings. These two classes are a speciality ; they 
 stand distinctly apart from each other in their modes of 
 moulding, and the flat moulder would make but an indifferent 
 hand at hollow work, and vice versa. Jobbing work comprises 
 jobs of any kind, no matter what they may be, from a 
 smoothing iron up to a large . lathe-bed. The jobbing sand- 
 moulder is ready to undertake anything that ma\^ come in 
 his way, even to making a pot, a grate, or a balcon3\ 
 
 LIGHT GEEEN-SAND WOEK. 
 
 By casting" is meant the process of converting fusible 
 metal into any given form by pouring it when in a liquid 
 ^state into a mould. There is no article capable of being pro- 
 duced in wrought iron which the sand-moulder cannot cast in 
 metal ; nay more, an ingenious sand-moulder can produce in 
 cast iron what no worker in wrought iron would dare to 
 attempt. It does not come within the scope of the present 
 treatise to enumerate overfishing for which science and com- 
 merce are indebted to the iron-founder ; but among the most 
 striking may be mentioned those which have superseded the 
 use of wood and stone — as frames for machinery, waggon- 
 races, spandrils for roofs, columns, waggons, bridges, barges, 
 churches, bearers, doors, and window frames ; in fact, time 
 and paper (if we may use the phrase) would fail us to enumerate 
 the uses to which cast-iron is now applied. 
 
 Like every thing else the art of moulding has made great 
 advances in all its branches, but more especially in light 
 
IBON FOUNDING. 
 
 greGEL-sand moulding. The old adage that necessity is tlie 
 mother of invention " has held good in this branch of 
 industry to a marked degree. The great demand for light cast- 
 iron work (ornamental and useful) that has taken place 
 within the last twenty years has brought out the ingenuity 
 of men who were not, in some instances, moulders at all, to 
 devise some kind of mechanism to assist the moulder in this 
 object, and the result of their inventions has been most 
 gratifying. 
 
 Suppose we speak first of light ornamental work, such as 
 balconies as they were moulded twenty years ago. It was 
 tlien considered to be a good tvv'o hours' work to ram the drag 
 part of a box (bottom part) that contained an ornamental 
 balcony 4 feet by 4 feet 6 inches, and make its parting all 
 ready for the top part, and this when the moulder had a 
 turning-over board to assist him. At the present time a 
 moulder can make two such balconies ready to receive the 
 metal in three hours. If we take balusters, it was considered 
 twenty years since a good morning's work of three hours to 
 mould one box of five balusters, and make the parting of the 
 second, with the assistance of a turning-over board. A box 
 of the same kind of balusters can now be moulded every 
 hour. 
 
 This improved plan of moulding is done b}^ what is termed 
 ^' plate moulding." A plate sufficiently large for the edge of 
 the box to rest upon is cast with the exact half of the required 
 pattern, the boxes having planed edges to fit closely on the 
 plate, where provision is made to ensure that ever}' box shall 
 fit to a hair's-breadth in the same position, and each half of 
 a box is also made to suit its other part to a hair's-breadth 
 when they are joined together. 
 
 The principal object in plate work is to save time in making 
 the parting, and to facilitate by a simple mechanism the 
 turning over of each part of a box when rammed. Herein 
 
76 
 
 A TREATISE ON 
 
 lies the whole secret of plate-moulding. "When wood turning- 
 over boards were in use they were supposed to be quite 
 capable of being moulded from. A rude and roughly^made 
 shape of the desired pattern was cut into the wood to receive 
 the exact half of the pattern, the fine ornamental parts 
 of the pattern being unheeded after the box was turned 
 over and the board lifted off ; then began the work of 
 the moulder to make the parting at the proper place 
 in the intricacies and more delicate parts of the pattern. This 
 of a necessity took a long time, as the parting in this kind of 
 work must be rightly and properly made, otherwise poor cast- 
 ings are inevitable. We may say here in passing that making 
 the parting in moulding, in all its branches, is a most impor- 
 tant item for the moulder ; first, the best place to make the 
 parting ; second, to make the parting correct after the place 
 has been decided on. In some patterns the parting can only 
 be made in one place, and that the centre. This applies to all 
 round bodies, such as pipes, columns, round balusters, light 
 ornamental work, &c. In other classes of heavier work the 
 moulder's experience and taste lead him to the proper place 
 in the pattern where the parting should be made. Hence 
 the great necessity of something to aid the moulder in making 
 his parting in light green-sand work, resulting in what is 
 well known as plate moulding. 
 
 This method is greatly in use for other classes of work 
 besides the ornamental, namely, looms for mills, sewing 
 machines, and various other articles. 
 
 Some foundries use plaster of Paris for their patterns in- 
 stead of iron, but on the same principle as the plate-moulding, 
 with this difference, that the plaster pattern is on a box of 
 exactly the same kind as that from which they are to be 
 moulded, the same machine being used to turn them over 
 when rammed up. Not only does plate-moulding make the 
 parting, it draws the pattern as well, and far more steadily 
 
IBON FOUNDING. 
 
 77 
 
 and better than the moulder can. When a frame for a 
 loom or a balcony pattern had to be drawn^ before plate- 
 moulding came into use, it required three and sometimes 
 four moulders to do it ; in this way taking the men from 
 other work. These four men were not necessary on account 
 of the weight of the pattern, but because each had to take a 
 corner so as to ensure a steady draw. 
 
 When the job in hand requires a large box, say five or six 
 feet square and six inches deep, hydraulic power is made use 
 of. The ram being down at its lowest, the half -box or plate 
 containing the pattern is laid upon a sole plate on the top of 
 the ram. The half -box to be rammed up is then lowered by 
 the crane on to its place. After the ramming is complete a 
 simple piece of mechanism fixes the box or plate together, 
 and the ram is then raised to the proper height, so that the 
 box may have room to turn completely over on swivels cast 
 on the box. On each side of the ram are pillars, where pro- 
 vision is made for the swivels of the box to catch, and the 
 ram being lowered, the whole is turned over. The ram is 
 again raised to receive the rammed-up box, another provi- 
 sion being made from the pillar to retain the plate or box 
 with the pattern whilst the rammed box is slowly lowered 
 down to the ram's seat. The other part of the box is done in 
 like manner ; they are then both put together and clamped, 
 and the mould is ready for casting. 
 
 The small work in plate-moulding is of course done by 
 hand, but it is on the same principle as the above. 
 
 PLATE MOULDING. 
 
 This class of work is a speciality, requiring special appli- 
 ances to enable the moulder to turn out a large quantity of 
 work. We do not regard it as moulding proper. An 
 apprentice brought up wholly, in the strict sense of the word, 
 to this class of work could scarcely be termed a moulder ; 
 
 o 
 
78 
 
 A TREATISE OX 
 
 he would be quite ignorant of the fundamental principles 
 of founding, having neither vents, cores, chaplets, binding, 
 nor different plans of running to contend with. It is a 
 mastery of these that constitutes a moulder. 
 
 In all kinds of light work made, or assisted to be made, by 
 machinery, no expense is spared in getting up first-class 
 patterns, which, as the moulders sa^^, would mould them- 
 selves. In order to save ramming, boxes are made the exact 
 shape of the pattern, but four or five inches larger all round, 
 for the purpose of bearing, otherwise the edges are j)laned, 
 holes for pins are bored, and pins turned. This work 
 is expensive at first, but the quantity of castings wanted 
 requires it to be done. The moulder, then, has little more to 
 care for than to keep his sand in good order and ram it to the 
 requisite degree of firmness. B}^ good order, or condition, 
 we mean the sand to be often riddled and sufiicientl}^ damp 
 to make it cohesive. It is better to err on the dry side than 
 other svise for this class of work. The metal used for 
 these castings should be of the softest and finest brand, 
 known as No. 1 . Two reasons recj^uire this — first, the greater 
 fusibility of the metal and adaptation for running ; and, 
 second, the damp sand tends to make the metal hard, the 
 castings being so light that they become in a manner chilled 
 through losing a portion of the carbon in the metal. 
 
 The apprentice who is taken from the core-bench in a 
 foundry where no speciality is carried on in castings of the 
 class we have just described, but where he may have had to 
 make moulds of every conceivable shape and form, will make 
 the best moulder, more especially if he has been a good core- 
 maker. The little jobs which he gets to mould he may think 
 insignificant, but such is not the case in reality. If he cannot 
 learn to mould a small one well, he will never be able to do 
 a large one well. In light green-sand jobbing work nearly 
 the same routine has to be gone thi-ough as in heavy green 
 
IRON FOUNDING. 
 
 7n 
 
 sand, the difference being that the appliances are smaller 
 and not quite so elaborate. 
 
 We will now consider and explain, as precisely as may be 
 certain things to be observed in moulding light jobbing 
 green-sand castings. First, the facing sand and sand for 
 filling the box must be in good order ; that is, free from 
 scraps and not too damp ; but it is impossible to state in words 
 the exact degree of dampness required ; experience and 
 practice alone can define that. AVe might say that the sand 
 is damp enough when it is fit to crush into a ball by the 
 hand ; but the fact is that sand too dry for moulding can be 
 made into a ball with a little trouble, and the same thing- 
 may be done with sand too damp, with only this difference, 
 that the operation is quite easy ; a medium e<msistency, then, 
 is the right thing. Bad results occur to small eastings wlien 
 the sand is the least shade too damp ; the body of metal being 
 so light in the mould, and the sand not so porous as it ought 
 to be owing to the dampness, the metal cannot rest and is 
 thrown out at the gate, if not all, a portion suflieiently large 
 to cause a bad casting. Another evil takes place even when 
 the metal does lie in the mould — the casting i^^ liable to 
 be slightly chilled, producing on the top when the skin is 
 broken small ^'porie" holes, as if worms had made their 
 abode their, and the casting having all the appearance of 
 being cast with No. 4 iron, instead of with Xo. 1 or 2. The 
 dampness takes a certain portion of carbon from the metal, 
 thus changing its character, as in the case previously men-, 
 tioned. AVhen the moulder finds that his day's work of 
 casting has been done in sand too damp, he should put no 
 water on his sand for the next day's moulding. In this way 
 the sand will be restored to a proper consistency. 
 
 In all kinds of light work the castings are taken from the 
 sand soon after being cast, which generally closes the day's 
 work. Two reasons call for this being done — first, if the 
 
80 
 
 A TREATISE ON 
 
 eastings were left in the mouki till next morning they -would 
 shew signs of becoming oxidised, or rusty ; second, the sand 
 is better to lie over night after being watered ; in the 
 morning it only requires to be turned over and raised in a 
 long heap, when it is again ready for use. The moulder 
 should keep his shovel perfectly clean and bright. 
 
 In all kinds of small jobbing work, as in machinery or 
 agricultural implements, the patterns, if they are rightly 
 made, will clearly shew to the moulder what part of the cast- 
 ing is intended to be cast upwards ; the pattern being slightly 
 tapered, the narrowest part will be cast in the bottom part of 
 the box. "When the pattern has a flat service, and thai; the 
 widest or largest part, a board is used, termed a turning- 
 over board, because it retains the pattern during the time 
 that the box is being turned over after being rammed up ; 
 this board is made for the purpose, and of a proper size to 
 suit the boxes that are generally used for small job castings^ 
 These boxes are generally twelve or fifteen inches square and 
 four or five inches deep, having pins fixed on three snugs, 
 two on one side and one on the side opposite, with a handle 
 on each of the other sides ; this is termed the drag or bottom 
 part. The top part is a fac-simile of it, only it has holes in the 
 snugs to receive the pins. From one to twenty small patterns, 
 may be put into one of these boxes and all cast together. 
 
 The drag part being rammed up and turned over on a soft 
 level bed, the parting is next made as follows : — The sand 
 close to the edge or edges of the pattern is made fi^rm with 
 the fingers, and soft hollow parts are filled up ; a sprinkling 
 of loose sand is smartly thrown over all with the left hand, 
 the right hand sleeking all down smooth with the troweL 
 The loose sand remaining can either be brushed or blown off, 
 and the pattern is then ready for the parting sand. Care 
 must be taken that little or no parting sand is allowed to remain 
 on the pattern; however fine it may be, as the eastings in that 
 
IRON FOUNDING. 
 
 Hi 
 
 case -would be liable to sbeTT some rougliness on the top. 
 The top part is next ]3iit on, the moulder noting that the box 
 is bearing properh^ that is, not rocking. In jobbing 
 foundries the boxes, as a rule, do not fit well ; the edges on 
 which they rest are rough and unequal, the pins slack, and 
 the holes get worn wide ; however well the}' may have been 
 fitted up at first, after being in use for some time the}' become 
 misplaced, and ultimately they get so mixed that out of the 
 whole original number there may not be two that can be said 
 to fit properly. In order to obviate the results of badly-fitting 
 boxes every moulder should, when he is putting on a top 
 part, incline the box hard one way ; this inclining is termed 
 
 sun about," or the way the sun travels ; and the same rule 
 is observed when the box is closed previous to casting. 
 
 The gate-pin is now set into the box ; it is a piece of wood 
 eight inches in length and one-and-a-quarter inches in 
 diameter, slighly tapered, and having a sharp point. When 
 there is more than one pattern in the box the pin is usually 
 set in the middle ; but when there is only one it is set two 
 or three inches from the side, or it may be set on the top of 
 the pattern, according as the latter may require. The top part 
 is now rammed up in like manner to the bottom, and the sand 
 is scooped out to a certain depth round the gate-pin, so as to 
 form a cup shape, in order that the metal may easily be 
 admitted from the ladle into the gate. 
 
 The proper and careful formation of this cup shape round 
 the pin is of considerable importance, more so than many 
 moulders imagine, because when it is well shaped and as deep 
 as possible the metal is passed into the mould cleaner than 
 when it is otherwise, and a clean cast for small castings is 
 very important. The top part is now lifted off and laid upon 
 its back, and the sand close to the edge of the pattern made 
 damp with water, either with a brush or swab, so that the 
 edges of the mould may become firm ; but too much water in 
 
82 
 
 A TREATISE ON 
 
 swabbing small moulds is bad, as the edges of the castings 
 become ciiilled and difficult to file or chip, therefore the less 
 of swab water tlie small moulds get the better. Should the 
 pattern be iron or wood it must be shaken in the sand before 
 being drawn. When it is wood a sharp spike or strong nail 
 should be driven carefully into the pattern and gently rapped 
 from right to left until the pattern in a manner feels free ; when 
 iron a small hole is drilled for the purpose of rapping and 
 drawing, it may then be steadil}' and smartly drawn out, so that, 
 when the pattern has been properly made, it leaves the mould 
 free from a disturbed part. The moulder has then only to cut a 
 small runner from the mould to where the gate-pin has been 
 inserted, and the mould is then ready for casting. 
 
 jilany foundries use blacking on all kinds of sand' work, 
 both light and heavy, the dry blacking being put into a small 
 cotton bag for light work, and into a coarse flannel bag for 
 heavy work, the bags being shaken close to the mould until 
 the proper quantity has been retained on the sand. A^Tiere 
 rotten rock and Belfast sand are used for moulding the blacking 
 bag is always adopted, the grain of this sand being so open 
 that did it not receive a certain portion of blacking to fill the 
 pores the castings would be ver^- rough ;but where Erith sand 
 is used there is no need for the blacking bag, the texture of 
 the sand being much finer than the others. 
 
 The blacking of sand moulds is done for two purposes — 
 first, to fill up the pores in the sand ; second, to make the 
 casting skin, that is, to cause the sand to quit the casting 
 freely, assisting in this action the coal dust that has been 
 mixed with the facing sand. When blacking has to be used it 
 should be of the best quality, viz., heavy and thoroughly 
 calcined, so that it may be impervious to the heat of the 
 metal, otherwise it will do more harm than good by getting 
 burnt in tile mould, and the residue running before the metal 
 into corners of the mould, giving the casting an appearance 
 
IRON FOUNDING. 
 
 83 
 
 of having been cast witli dull iron, as well as being rough.. 
 The patent blacking brought to the notice of moulders about 
 eight years since by a Glasgow firm, completely fulfils all 
 the requirements of good blacking. 
 
 But even with this patent blacking light castings, or rather 
 moulds for light castings, should receive as little of it as 
 possibly can be done without, especially small ones which 
 have to be turned or planed. They are much cleaner cast in 
 Erith sand, with a proper quantity of fine coal dust in the 
 facing sand, and no blacking. For ornamental work moulded 
 in any kind of sand it is enough when the blacking can just 
 be seen on the mould. In heavy green-sand work blacking 
 can be used with more freedom, as in such cases it can be 
 pressed and sleeked with the trowel and other tools into the 
 pores of the sand, thus making a smooth moidd, and render- 
 ing it impossible for good blacking to run before the metal 
 at the time of casting. 
 
 When small castings require holes running through them, 
 either round or square, the moulder should see that the cores 
 he has to put into his mould are of the proper form , not to 
 have a core more oval than round, or what should be a 
 square one not square at all. Few things look worse in a 
 small casting than a misshapen hole, or when they are not per- 
 fectly straight in the casting. The moulder should make cer- 
 tain that the vent is clear and the core dry. He may take his 
 vent either through the top part or down through the drag; some 
 moulders prefer the one to the other, but the vent must come 
 off whether it be up or down. The cores should not be put 
 in the moulds till near the time of casting, as they soon 
 absorb the ^ moisture from the green-sand ; but when it 
 happens that the moulds are not cast on the same day as they 
 are cored they should be taken out and cored next day. 
 When they are left in the mould till next day, as is some- 
 times done, every casting is sure to be more or less blown. 
 
84 
 
 A TREATISE ON 
 
 HEAVY CASTINGS IN GEEEN-SAND AND 
 DEY-SAND. 
 
 Green-sancl and dry-sand moidding are both executed 
 nearly in the same fashion. In working dry-sand more 
 liberty can be taken with the mould during the process of 
 moulding, and, after the mould has been dried, in putting it 
 together to make ready for casting. 
 
 Heav}' work in green-sand means castings of from five 
 hundredweight up to ten tons in weight, and sometimes even 
 more. As the method of moulding light green-sand castings 
 has improved during the last twenty years, so also has heavy 
 work done in green-sand and dry-sand. Elaborate and intri- 
 cate castings that used to be cast in diy-sand are now executed 
 in green-sand, and work that was wont to be done in loam is 
 now successfully carried out in dry sand. AYhat, then, shall 
 we say of the moulding machines for heavy work that are 
 now in common use, such as for ramming up jiipes, railway 
 chairs, telegraph posts, and, notably, wheel and pulley 
 moulding machines ? Again, the moulder can chill and make 
 harder than steel any part or parts of his casting that may 
 require it. And, lastly, he can make castings from metal 
 which are almost equal to malleable iron in tenacity and 
 softness. 
 
 It would be entirely out of our proper province — viz. iron 
 founding, or the art of moulding — to explain either with 
 plates or diagrams the different moulding machines which 
 some foundries, where special castings are made, have 
 now in daily use ; but we cannot refrain from saying a few 
 words about one of them — " Scott's Manchester AYheel and 
 Pulley Machine." For simplicity of design, the quality of 
 not being easily put out of order, and the merit of being 
 suited to its work, this machine cannot be surpassed. No 
 
IRON FOUNDING, 
 
 85 
 
 foundry where pulleys or wheels of any size are occasionally 
 made should be without it. 
 
 We will, then, confine ourselves to green-sand and dry- 
 sand moulding wholly done by hand, and of such a nature 
 that machines could scarcely be applied to it. 
 
 The green or dry-sand moulder may have occasion, as cir- 
 €umstances require, to work with a one, two, or three-part 
 box ; and the dry-sand moulder has sometimes to do without 
 
 box of any description, merely casting a rough plate, which 
 when large is three and a quarter inches thick, the proper 
 shape of the pattern allowing it to be nine or ten inches 
 larger all round for bearing. This plate is cast full of square 
 holes, nine inches by five, to enable the moulder to ram the 
 sand on the top of the pattern, the plate having prods" or 
 
 dabbers" six or oight inches long (as the pattern may 
 require) to retain and carry up the rammed sand. The 
 pattern in this case would have to be moulded in the foundry 
 floor and dried there, the plate merely covering the top surface. 
 
 When the moulder cannot get a two-part box to suit his 
 pattern he will proceed to mould the latter in the floor. This 
 is termed bedding it down," and it then may be covered 
 with a one-part box. 
 
 In primitive moulding this woTdd not have been thought 
 of. Two parts of a box were then used, and the boxes were 
 made of wood, and wooden boxes are still in use in some 
 of our agricultural districts ; also in many foundries in 
 America and the East and West Indies. But in great indus- 
 trial centres where foundries flourish, and where the blaze of 
 the cupola is seldom extinct — where the castings are heavy 
 and cosmopolitan, being of every conceivable shape and form, 
 the wooden box would be of no use whatever. Although 
 moulding in a box with two parts is decidedly the best for 
 the pattern, better for the moidder, and best of all for the 
 casting, still no foundry tliat pretends to do anything like a 
 
86 
 
 A TREATISE ON 
 
 casting business could really entertain tlie idea of moulding 
 all its castings in two or in three-part boxes, and this for two 
 reasons — (1) the great number of boxes that would be 
 required ; (2) the great weight of, and the difficulty and 
 danger in handling, heavy two-part boxes. Hence the plan 
 of bedding down patterns in the floor is resorted to. 
 
 A moulding box, whether intended to be used in green 
 sand or dry sand, but more especially the former, ought to be 
 strong and rigid, giving no signs of yielding when filled with 
 sand, or during the process of turning it over. AVhen the 
 casting is long, say twenty feet, it is usual to cover it with 
 two boxes, the moulder choosing the best place where to 
 make the joining, so as to shew the least possible mark of the 
 latter ujDon the casting. The two boxes are easy to handle, 
 take up less room on the foundry floor, and no risk occurs of 
 the box yielding, as it certainly would be liable to do unless 
 it had been made enormously heavy. 
 
 When two boxes are used to cover a long mould great care 
 has to be observed in forming the joint between the two. 
 When they are first put on in order to be rammed up, it is 
 requisite that the two ends next the joint should be an inch 
 separate, which space allows three-eighths of an inch of sand 
 to be -put on the end of each box, this being done after they 
 are parted from the pattern, so as to allow a quarter of an 
 inch of space between the two after they are closed. This 
 space is called " the fin," and cannot be dispensed with in 
 this case, as it would not be safe to make up the sand so as to 
 fill up the entire space between the boxes. 
 
 Some moulders are accustomed to use clay water for the 
 purj)ose of causing the sand to adhere to the ends of the 
 boxes. This is most reprehensible, unless the water be put 
 on with extreme care, as it causes the sand to be too damp ; 
 the metal rising up in the space, a violent commotion at once 
 takes place, penetrating down into the mould, and in many 
 
IRON FOUNDING. 
 
 87 
 
 cases ruins the casting*. The safest plan with a joint of 
 this description is to oil, instead of clay-wash, the ends of the 
 boxes ; the sand will adhere equally well, and should it be 
 very moist with the oil no irruption will be caused with the 
 metal. After the boxes are closed a little waste hemp or flax 
 is gently stuffed into the joint, over this is packed some fine 
 sand, and light weights are laid upon the top of all, when the 
 securing of the whole may be considered complete. 
 
 The materials which the green-sand moulder uses are — 
 sand, pieces of iron (cast or malleable) to strengthen parts of 
 the mould where they may be required, and a box or cast- 
 iron frame with traverses, commonly called " bars," running 
 across at proper intervals or spaces, according to the depth of 
 the box. These bars stiffen the outside frame and hold the 
 sand firm that has been rammed between them, so tliat the 
 pressure of the metal can take no effect in forcing the sand 
 out. 
 
 In foundries 's^'horo all kinds of work are executed the 
 boxes will be varied in size and in weight, from thirty pounds 
 up to three tons. It is of great importance to the sand- 
 moulder that he should have a good and well-fitting box to 
 mould his job in ; the box, however, is too often tlie reverse 
 of this. The operator in a jobbing foundry has often many 
 schemes to devise, and much time is spent in making a mould 
 with a broken or badly-suiting box. Some of the most suitable 
 boxes for jobbing foundries of which we know are those 
 made with deep sides, say nine inclies, and sliallow bars of 
 four inches. They may bo from three to five feet broad, and 
 from ten to thirteen feet in length ; and no foundry sliould 
 be without a few of them. They suit well in many instances 
 for saving deep lifts and economising time in making elabo- 
 rate partings ; besides, they can be turned upside down and 
 used for a mould, having a plain surface and a plain parting. 
 
 A sand-moulder may get a pattern to make a casting from 
 
SH A TREATISE ON 
 
 ^hich really puzzles him as to which, way will be the best to 
 mould it. The piece of work to be moulded may require 
 portions of the pattern to be made in such a manner that they 
 will sej)arate, one piece from another, and according to the 
 p)attern-maker's point of view this may be the way it should 
 be moulded ; but when it comes into the moulder's hands he 
 at once sees that the pattern has not been made with the best 
 idea of how it should be moulded. This occurs in many 
 instances, and gives a great deal of extra trouble to the 
 moulder. After considering how to run it in, and the vents 
 from the cores (when there are any,) he is obliged to decide 
 on the best way to mould it by reference to the only box that 
 will suit, and that may be very imperfectly fitted for the 
 purpose. It is the prevailing custom in many foundries to 
 break a bar or even two out of the box to make it suit the 
 pattern, on account of the pattern coming in the way of a bar 
 or a bar coming in the way of a part of the pattern. This 
 23ractice should be avoided as much as possible, as the box 
 when deprived of its traverses in this matter is liable to 
 become useless for moulding purposes. 
 
 Moulding boxes made with the intention of appljdng them 
 to man}^ jobs, and not one in particular, ought to have the 
 bars cast separate, and bolted to the outside frame ; the bars 
 to be cast double, so that one bolt in each end will hold two 
 bars. In this way bars can be taken out to s^it the pattern, 
 and they can be put in again without the box being injured. 
 Boxes of this description would certainly cost more to begin 
 with, but the J would be cheaper in the end. 
 
 The foundiy floor is now used extensively for moulding 
 purposes, much more so than it was twenty years back, the 
 reason being that moulding is now better understood than it 
 was then. A pattern can now be bedded in the foundry floor 
 in the same time that it would have taken a moulder to look 
 for a two-part box in which to mould his job. . Seeing that 
 
IRON FOUNDING. ■ W 
 
 such a custom is now general in foundries, we cannot do 
 better tlian proceed to explain more fully the art of moulding- 
 in green-sand with a one-part box, generally known as 
 ^' bedding the pattern down." 
 
 A great deal depends upon the formation of the pattern as 
 to which way the moulder will proceed after the hole is made 
 to receive it. When the part of the pattern that is to be 
 cast downwards presents a plain surface a levelled bed of 
 riddled sand is first made in the bottom of the excavation ; 
 three inches of common riddled sand and one inch of facing 
 or coal-dust sand should be between the surface of the bed 
 and the top of the ashes intended to carry off the vent. This, 
 bed of sand should be made very carefully, is seldom rammed 
 with a rammer, and when it is rammed the operation is per^ 
 formed very slightly ; tramping with the feet is generally 
 sufficient for the heaviest green-sand castings. This bed of 
 sand is formed with two pieces of wooden laths, each having 
 a perfectly straight edge, known in some foundries as straight 
 edges, and another one, generally called a parallel straight 
 edge, rests upon the other two, parallel with them, as they 
 are levelled by it. The sand being now straked off, and tho 
 bed having being vented, facing sand is sieved all over it and 
 the whole sleeked carefully down with the trowel ; it is then 
 ready to receive the pattern. Should there be any j)rotu- 
 berant parts on the face of the pattern, such as prints for 
 cores, facing strips, and the like, they will make an inden- 
 tation and keep the pattern from resting upon the bed. It 
 must then be lifted off, after it has been carefully staked, so 
 that it may go into the same place again. The projecting 
 parts are taken from the pattern, and they are then sunk flush 
 into the bed. When there are to be cores in some part of the 
 mould, small wooden plugs three inches square, or little cast- 
 iron sockets, are sunk into the bed two inches below the 
 surface, and at arranged distances from each other, in order 
 
so 
 
 A TREATISE ON 
 
 that the chaplets to carry the cores may rest upon them. 
 "WTien the plugs are wood, the chaplet-stalk lias a sharp 
 point, but when iron sockets are used, the stalk is kept blunt. 
 This arrangement only applies to green-sand. 
 
 It is sometimes advisable to finish this part of the 
 mould in its early stage, as the moulder can get to work 
 at it with greater freedom, and therefore, it is more quickly 
 done than when the whole mould is made. The pattern is again 
 laid on the bed, this time resting equally all over, the stakes 
 are withdi-awn, and the ramming up of the outside is pro- 
 ceeded with. The formation of the outside may require some 
 part or parts of the ramming up to be made so that they can 
 be separated to enable parts of the pattern to be taken from 
 the mould and allow the moulder to get these parts finished, 
 AVhen such is the case these are termed drawbacks." The 
 part of the mould that is to remain in the floor is first rammed 
 up, and pieces of board set up at those places where the fixed 
 ramming terminates and the drawback begins, so that the 
 moulder may have something to withstand the ramming. 
 A course or depth of six inches of sand is rammed at a time 
 until the top of the pattern is reached, two inches of facing 
 sand being kept close to the pattern. On every second com-se 
 of sand pieces of iron, cast for the purpose, are laid three 
 quarters of an inch square and twelve or fourteen inches in 
 length ; they are laid horizontally, three inches between each, 
 and clay-watered at the ends that go next to the pattern, 
 being kept back half an inch from it. These irons strengthen 
 the sand, and materially assist the gases to leave the face of 
 the sand forming the mould. 
 
 When the mould has been half-way rammed up it is 
 advisable to strike the pattern in a lateral direction all round 
 with a heavy hammer, which slackens it to a certain extent 
 and causes it to leave the mould more easily when it has to 
 be di^awn. The parting for the drawbacks are now made. 
 
91 
 
 This is an important part of the moulder's work, as a well- 
 made parting", and good parting sand, constitute two of 
 the necessary elements that go towards effecting speedy 
 closure of the mould. . By a well-made parting we mean that 
 the sand should be straight, regular, and firm ; the parting 
 sand that is put upon the sides must be wet to enable it to 
 adhere, and should be of a fine qualit3\ A plate cast for the 
 purpose is usually made to carry the sand that forms the 
 drawback, and according to the weight of sand that it has to 
 carry so will its strength have to be. It should not when 
 lifted from its bed give the least signs of yielding. If there 
 are three feet of sand the plates are generally cast two and a 
 quarter inches thick and fourteen inches broad. They are 
 usually bedded the thickness of themselves below the losvest 
 part of the pattern, and have a bevelled edge, which is to be 
 upwards, so that sand on it is not required. These drawback 
 plates have two or three wrought iron lifters cast in them at 
 proper intervals, for the purpose of slinging them when they 
 are to be hoisted out of their places. 
 
 Drawbacks are rammed up in the same manner as the part 
 of the mould that is to remain in the floor, except that double 
 the number of strengthening irons are used, the}' being put 
 in every course of sand, instead of every second one. 
 
 The pattern being now all rammed up to the top, the box 
 that is to cover it is now tried on and placed in such a position 
 as will suit vents, running- gates, and flow-gates. It is then 
 securely staked at each corner, lifted off, and the parting 
 made. 
 
 When the parting has a level surface it is necessary to put 
 two inches of facing sand upon it previous to the box being 
 put on for good, as the cross-bars or traverses coming hard 
 on the sand make the face of the bars firm. Where the 
 pattern is three or four inches (and sometimes more) from the 
 bars this would not require to be done. 
 
02 
 
 A TREATISE ON 
 
 Assuming the box to be in its place, and the gate-jDins in 
 tlieir places, the box only remains to be rammed up. An inch 
 or so of facing sand is riddled from a quarter riddle all over 
 the pattern and parting, and cast or wrought irons, made for 
 the purpose, are plentifully distributed between every pair of 
 bars in the box, care being taken that they do 7iot stand 
 higher than the bars. These irons are sometimes called 
 '^lifters," from the two inch toe that is cast on them, and 
 in some foundi^ies they are called *' hangers." They are for 
 the purpose of strengthening the sand between the bars of 
 the box and the pattern. When they are too near the face of 
 the mould — say that only a skin of sand intervenes — marks of 
 them will be seen on the casting. Marks of the bars will 
 likewise be seen when they are too close to the casting. As 
 tbe sand is liable not to be rammed properly, lumps or 
 swellings are seen at every bar. Again, marks may be 
 produced on the casting wben the bars are at too great a 
 distance from each other, especially when the pressure of 
 the metal is considerable ; between every two bars the 
 casting will be slightly swollen, this being seen very plainly 
 after the casting has been painted. The distance between 
 
 ch pair of bars should never exceed six inches for heavy 
 work ; and the sand on the face of the bars should in no case 
 be less than an inch. This rule applies to round bodies just 
 the same as to flat surfaces. 
 
 The box being lifted oif , and tlie vents all attended to, the 
 edges of the mould close to the pattern are freely swabbed 
 with water ; the pattern is then slackened in the sand by the 
 use of a strong bar inserted in the places appointed, and a 
 heav}' hammer is applied in striking the bar in a lateral 
 direction. 
 
 A green-sand mould of this description, made with either 
 Erith sand or rotten-rock and BeKast, will be finished much 
 after the same manner, if we except that when made with the 
 
inON FOUNDING. 
 
 93 
 
 sand first spoken of water is used much more freely all over 
 tlie mould than with the latter. A mould of this kind when 
 made with Erith sand would be slightly dried — or rather, 
 skin-dried — with fire-lamps after being finished, and it would 
 not be blackened with blacking ; a greater quantity of coal- 
 dust being used in this instance with the Erith facing sand is 
 capable of making a good skin on the casting. 
 
 The drawbacks being lifted from their places, every part of 
 the mould will be finished in detail, soft parts made fiim, and 
 three or four inch brads used freely where parts of the mould 
 have been started or torn up with the drawing of the pattern. 
 Fillets or round corners must be made regular, and a small 
 vent-wire (13-wire gauge) passed freely from all prominent 
 parts of the mould to catch the larger vents that were made 
 before the pattern was di-awn, and the whole is carefully 
 sleeked with the trowel or other tool that may suit. When, 
 however, the mould is made with Belfast and rotten-rock 
 sand it is not entirely finished until it has received a heavy 
 coat of dry blacking shaken out of a bag. 
 
 If the pattern happens to be of such a construction that it 
 offers no place to rest upon on a level bed, it is merely laid 
 in the place that has been formed in the floor for it. Coarse 
 riddled-sand is rammed as well as possible under the bottom 
 parts, and it is then staked and lifted off, the soft parts made 
 firm, prominent parts carefully ironed, the vent- wire passed 
 freely to the open bed below, and the whole covered with 
 facing-sand. The pattern is then put on its place and rapped 
 or struck with a heavy hammer until the moulder is satisfied 
 that the sand underneath is sufficiently firm, when the rest of 
 the ramming may be proceeded with. 
 
 Moulding in green-sand with dried cores may be considered 
 a mixed operation, and the moulder should be as conversant 
 with the nature of the cores that he uses as he is with the 
 sand from which he has made his mould. An important 
 
 H 
 
A TREATISE ON 
 
 piece of work may be ruined simj^ly owing to a small core 
 being defectiye. When, however, a moulder has been a good 
 core-maker he will have no trouble in finding out any imper- 
 fections that may exist in his cores, such as improper sand 
 and venting, imperfect di-ying, and a lack of careful strength- 
 ening with irons. When a moulder gets a core betra^dng 
 any of these imperfections he should on no account put it into 
 his mould, even though such carelessness should furnish him 
 with the too common excuse after the casting has been found 
 to be fault}^ — The core that I used was not this or was not 
 that." Such a plea is scarcely an excuse for a bad casting. 
 A careful moulder will have an eye to the making of his 
 cores during the time that he is getting his mould ready to 
 receive them. Cores are especially used in forming vacancies 
 in castings which cannot be successfully formed by the 
 pattern. 
 
 There is one evil that attends bedding a pattern down^ and 
 it is a common one, especiall}^ when the pattern has not been 
 firml}^ put together — the moulder is liable to ram or rap it 
 down out of its proper shape. This is more particularly the 
 case when the pattern is so formed that the under part, or 
 that part which is to form the bottom of the mould, has to be 
 rammed up fii'st, and then turned over on a bed of sand. 
 For instance, an H-shaped beam would be moulded in this 
 manner, and many are rejected from this cause, the casting 
 not being square. 
 
 BAD LIFTS WITH THE TOP PAET. 
 
 When a pattern on the top, that is, the part which is moulded 
 up, presents an irregular surface, drojoping in many places 
 eight or ten inches, these deep parts must be carefully 
 rammed, and the rammed sand secured with irons for the 
 purpose. When this has not been done, or done only imper- 
 fectly, a bad lift is the result — -meaning that all the sand has 
 
lEON FOUNDING. 
 
 not been brought clean away witb the top part, the moulder 
 having then to rectify and mend up the broken parts. Again, 
 a bad lift may be caused through a pattern being badly made, 
 parts of it having no taper or draw, but being perfectly- 
 square. When such is the case, after the pattern is drawn 
 from the mould and the top part mended up, the box should 
 be put on its place, and in this way any imperfections can be 
 found out, in many instances preventing the mould from 
 being crushed after it has been finished, as is liable to happen 
 when this is not done. A good and clean lift with the top 
 part should be the desire and aim of every moulder on what- 
 ever branch he may be engaged, as it saves him much trouble 
 and conduces to the production of a better casting. In 
 addition to a good lift it is of great importance that there 
 should be a good draw with the pattern. AVe know of 
 nothing more annoying to the moulder than when, after he 
 has had a clean lift and a well-made parting, he finds a great 
 portion of his mould or parting partiall}- destroyed owing to 
 the circumstance that the pattern has not been properly made 
 to leave the sand, or owing to due provision not having been 
 made to enable the moulder to slacken the pattern in the 
 sand. When this occurs, as is too often the ease, the top 
 part should be again tried on before the mould is finished, as 
 in the case of the bad lift. A bad lift, or a bad draw of the 
 pattern, or, as in some instances, both combined, may cause 
 two bad results to the casting — either a part of the mould is 
 crushed, or the casting is found to be marred by a large fin 
 or fins, the latter certainly being the least of the two evils. 
 It is, therefore, very essential that the top part of a mould 
 having deep lifts of sand should be securely staked at the 
 proper places, and that the stakes be of such length as to 
 enable the box to rise perfectly plumb from the parting until 
 it is clear of the pattern. These stakes should be well taken 
 care of, so that nothing may occur to disturb or loosen their 
 
06- 
 
 A TREATISE ON 
 
 hold of the floor until the box is closed and the job cast. 
 Green-sand moulds are tender to work with, requiring the 
 moulder to be quick of eye, and to possess a firm but gentle 
 hand. 
 
 It is usually the case that a good green-sand moulder, 
 when he is called upon to work with loam, becomes a first- 
 class moulder in that kind of work. He has been used to 
 pa}" more strict attention to the details and minor parts of a 
 mould — he makes better partings, strengthens weak parts 
 with irons, and gives attention to the venting and other 
 matters which the loam moulder would perhaps be disposed 
 to pass over, and lastly, he wiU finish the mould with better 
 taste, having been used to pay greater attention to these 
 things when he wrought with the sand. 
 
 DEY-SAND MOULDING. 
 Dry- sand castings are always rated higher in price than 
 green-sand ones, and this is only fair, seeing that the former 
 requires fuel and (as a rule) more elaborate provision in 
 moulding ; besides, the castings are undoubtedly sounder and 
 cleaner. When they weigh from half a hundredweight up 
 to a ton they are usually cast in two or three boxes, which 
 must fit well and be strong. They are always dried in a 
 stove. When they exceed the weights mentioned they are 
 bedded into the floor and moulded exactly as if in green-sand,, 
 and the mould receives its final touches with black-wash just 
 the same as the loam-mould. Dry sand is as near as possible 
 similar to loam, only in such condition that it is fit to be. 
 rammed. 
 
 The question may here be put — What is the meaning of 
 casting some things in dry-sand and others in green-sand ? 
 Could they not all be cast in green-sand, and thus save the 
 expense of diying ? We would say — ^Yes : many that are 
 made could be moulded and cast in green-sand, but the 
 extreme care that would be required in that case, together 
 
IRON iOUNDING. 
 
 07 
 
 with, the great liabilit}^ to mishaps, would far counterbalance 
 the expense of blacking and drying a mould. In many 
 instances it would scarcely be possible to ram a green-sand 
 mould sufficiently to withstand the pressure of the liquid 
 metal. Suppose we take a column, or pipe, nine feet in 
 length, and mould it in green-sand in a two-part box, as it 
 must be cast vertically, what pressure would there be at the 
 bottom of the mould after it was filled with metal ? A column 
 of liquid metal twelve inches in height has a pressure of 
 3*3 lbs. to the foot, nine times 3*3 are 29*7 lbs., and one foot 
 more for a head would give exactly 33 lbs. pressure on the 
 lowest part of the mould. The pressure quoted being such, 
 green sand cannot bear it with success ; of course the box 
 could be secured with plates, covering all the ramming, so 
 that the sand could not actualh^ be forced out ; but the casting 
 would be swollen into large lumps from the bottom half-way 
 up to the top ; besides, the sand would be eaten into the 
 metal in such-wise that no cleaner could make the casting 
 anything like smooth, and we very much fear that it would 
 be condemned. 
 
 Castings that must be clean and sound, such as locomotive 
 cylinders, slide-valves, pumps, &c., also the heavier class of 
 work, such as sole-plates, condensers, &c., are made in dr3'-sand 
 successfully, and, under certain circumstances, more cheaply 
 than when moulded in loam; they prove as good, and, in some 
 instances, are better castings. 
 
 Chaplets of the same kind as in loam are used in dry sand, 
 but when the mould becomes cold the}- are apt to sink into 
 the sand when the weight upon them is considerable. 
 Columns that are intended for important structures, such as 
 bridges, and to be immersed in water, or high-pressed steam 
 pipes, ought to be cast in dry-sand and run vertically. In 
 this case chaplets are not required, and the core is certain to 
 be in the centre of the casting. For purposes of lesser 
 
08 A TREATISE ON 
 
 iinj^ortaiice the work niav be cast in green- sand and run 
 horizontally. 
 
 In dry-sand, as Ave have already said, the extra soundness 
 and the greater closeness of the grain, all the properties of 
 the iron remaining combined, give the casting superior 
 strength over those cast in green sand. It seems to us that 
 east-iron in a liquid state takes more kindly to and rests more 
 easily within this species of mould than it does either in loam 
 or green-sand. 
 
 A mould may be built vrith bricks and loam, and when it 
 has a large and plain surface on the top it could not have a 
 better top part to cover it than one made with dry-sand. ' 
 
 LOAM MOULDING. 
 
 Loam moulding stands distinctly apart from either green- 
 sand or dry-sand moulding. The principles of all three 
 systems are, indeed, to a certain extent identical, but the 
 materials employed, as well as the manijDulation, are as 
 different as night is from day. By the principles we mean 
 the mode of running, and the plan of venting adopted in loam- 
 moulding, with the use of flow-gates, are as near as may be 
 akin to those employed in sand-moulding. 
 
 AYe have every reason to believe that loam-moulding is the 
 most ancient form or mode of making a mould either for 
 brass or cast-iron. Xo doubt Hiram, in Solomon's time, was 
 a thorough loam-moulder. We read that his foundry was 
 convenient for getting clay, ^1 Engs vii. 46) so that it is 
 more than probable all his heavy work for the Temple at 
 Jerusalem was cast in loam; such as the two great pillars, 
 Jaehin and Boaz, the brazen oxen, the molten sea, and the 
 brazen altar. Xo pattern would be made for such articles as 
 these ; in fact, we hear nothing of patterns at all. Hiram 
 would be his own pattern-maker. In this respect some of 
 our modern moulders may have reason to envy Solomon's 
 
IRON FOUNDING. 
 
 99 
 
 founder, as Hiram could liave his pattern made exactly to his 
 mind, t. e., to mould. AAHien we come later on, vre find that 
 all the heavy bells in China and other parts of the far East 
 were cast in loam, of which there is not the least doubt ; so 
 that we are quite justified in saying that loam moulding is 
 the most ancient form of producing a casting. 
 
 Of the three branches of moulding the loam is that in 
 which the moulder can best shew his superior ability and 
 genius. He has a broader field in which to exercise his 
 judgment than the sand-moulder, and, this being so, it is 
 hardly fair to say that of necessity he is a superior man to 
 the sand-moulder ; by no means — the one has greater scope 
 for his ability than the other. 
 
 A loam-moulder may and can make a casting from a com- 
 plete pattern, part of one, or none at all ; and we are safe in 
 saying that the less wood there is about a loam-mould the 
 better, because loam of any sort clings to wood, and therefore 
 irhen the pattern is drawn out of the mould the surface of the 
 loam presents a great many scales, as it were, and if these are 
 not carefully scraped off the mould the parts of the casting 
 upon which they have been left run a great risk of being 
 scabbed. When the moulder does not take this precaution 
 the metal seldom neglects to take them oft' for him. This is 
 one of the evils of wood in a loam mould. Another is that 
 when a complete and full pattern is made, the wet loam, 
 coupled with the heat that it gets, and which is necessary to 
 take the mould apart, causes the wood to warp and the joints 
 to open ; bye-Avood appears here and there, starting and in 
 many cases distm^bing the mould, and causing the latter to 
 be torn up on drawing out the pattern. There is yet another 
 evil ; should the mould get rather too much fire while the 
 pattern is in it the wood becomes shrunken, the screws and nails 
 lose their hold to a certain extent, and the moisture or 
 glutinous substance from the wood is absorbed by the loam, 
 
100 
 
 A TREATISE OS 
 
 causing the mould to be greasy, so that it refuses to absorb 
 the water requisite for the moulder to finish and make it 
 smooth ; more especially is this the case when the wood is 
 full of knots ; large parts of the loam have then to be 
 scraped off, and new loam substituted. It is a simple and 
 easy thing for a mould that has a pattern in it to get too 
 much heat, even to burning it out, leaving nothing but nails 
 and charcoal. This does not occur often, but we have seen it 
 happen with careful and first-class moulders ; therefore, for 
 the reasons we have given, the less wood there is about a 
 loam-mould the better. 
 
 Castings of irregular shape, be they large or small, that 
 are made in loam are best cast from a skeleton pattern. The 
 fact of a pattern being properly got up, so that the moulder 
 can make all his internal work, i.e.^ his cores, and the outride 
 as well, is itself one of the reasons why the cast should be 
 made in loam. This plan takes less time, less wood, and, in 
 short, is not nearly so expensive as the use of a full and 
 complete pattern, with all the core-boxes that it may require. 
 
 With a skeleton pattern the moulder is certain of having 
 his proper thicknesses when he comes to close his mould, as 
 the cores are bound to go where they came out of, leaving 
 the space of thickness formed by the wood between them ; 
 but this may be saying more than can be depended on when 
 a full and close pattern is wrought from, and the cores made 
 in boxes. 
 
 Again, when iron-sand loam is used to make the mould, 
 and the pattern is close and complete, the workman has much 
 extra labour in bringing the mould to a proper degree of 
 smoothness during the course of finishing, because all moulds 
 that are built from a pattern are more or less full of slight 
 hollows, and the skin has then to be broken with coarse 
 rubbers — strong wire carding, from cotton or flax mills. Fine 
 loam must then be ajDplied all over the sui'face to fill the 
 
IRON FOUNDING. idl" 
 
 hollows and to make the mould sufficiently smooth. With 
 Erith loam the labour is much less ; in fact, it is not to "be 
 compared with the work required in sand moulding, owing 
 to the natural fineness of the loam. 
 
 It is generally admitted that loam castings are stronger 
 than dry-sand or green-sand castings, dry-sand coming next 
 in strength, the reason of which is, we think, plain— the loam 
 casting becomes annealed in the mould ; the loam being a 
 non-condu.ctor of heat to a great extent helps to retain in the 
 iron all its strengthening properties. Dry-sand is next ; but 
 in green-sand the iron easily loses its most valuable qualities ; 
 the metal is cooled quickly, and in this way the casting be- 
 comes weak. 
 
 A loam-mould is composed of bricks, loam, and iron, and, 
 for venting purposes, straw or hay and ashes. The ashes 
 may be used, where the building is heavy, for filling up the 
 joints or spaces between the bricks, in the room of wet loam, 
 irrespective of venting, their use being simply to enable the 
 mould to be more easily dried. Old dried loam, or dried sand 
 and rubbish, suit nearly as well when ashes cannot be had. 
 The iron is for the purpose of strengthening the mould, /. e.y 
 the bricks and loam. 
 
 Loam-moulding seems to be better understood now than it 
 was twenty years since. Better castings are made, and they 
 are executed in a third of the time that used to be occupied 
 with them. 
 
 The open sand-bed is closely connected with loam-moulding. 
 It is on this bed of levelled sand that the moidder marks ofit 
 all his core-irons, building-plates, and bottom or base-plates, 
 as Avell as the top plates that cover them. Although these cast- 
 ings may be rough, onl}^ fit to be hidden away in bricks and 
 loam, and afterwards broken up when the casting is taken 
 from the moidd, nevertheless it is extremely necessary, nay it 
 is of vital moment for the safety and success of the casting, that 
 
i02 
 
 A TREATISE ON 
 
 the irons, plates, &c. connected with, and requisite to a loani 
 mould should be carefully marked and lined off on the bed 
 of rough, sand; and the moulder should see that they are 
 made up and cast exactly as lie has marked them off. 
 
 Twenty yearg ago the loam-inoulder had templets, made 
 from thin wood, of all the building-plates and core-irons, to 
 suit the different parts of his mould, but such a thing is not 
 dreamt of now. 
 
 The loam-moulder must be able to read drawings or 
 tracings, and from these make everything requisite for the 
 mould, from the base-jolate to the top. 
 
 It is usually the case that two or more moulders are 
 engaged in working at the same mould, and one of them has 
 what is termed the charge of the job, the others working 
 entirely to his suggestions. It is he who marks oif on the 
 sand-bed, and sees that all the plates and irons are cast to his 
 mind, a great deal depending on him for the quick despatch 
 and success of the casting. 
 
 AYhen the loam-moulder gets a pattern, or part of one, to 
 make a casting from, he will first consider the best way to 
 mould it. Other factors in the matter, however, have to be 
 considered as well, such as how the pattern is made and the 
 necessity of certain parts of the casting being absolutely clean 
 and sound. These considerations must influence his decision 
 before he settles on the method in which the work is to be 
 moulded ; the easiest fashion of moulding may not be the 
 best for the casting, and he cannot go against that considera- 
 tion. He then considers the cores, how and where they are 
 to be vented — how he is to run the casting — where it is 
 essential to have flow-gates — how the mould is to be bound 
 together — and lastly, how much metal will be required to fill 
 the mould, allowing so much for a head. 
 
 All loam-moulds are built upon a bottom plate, which 
 should be made strong enough (two or two and a half inches 
 
IRON FOUNDING. 
 
 in thickness) to be able to carry the mould without giving 
 signs of yielding under the weight ; that is, when they are 
 made on the floor and carried by the crane to a bogie for the 
 stove, in order for the mould to be dried. When the mould 
 is large, and the crane not capable of lifting a plate made 
 sufficiently strong to carry it and the mould together, the 
 plate is put into a pit made the proper depth, length, and 
 breadth. A plate to go into a pit need not be cast so thick as 
 one that carries the mould to the stove, because heavy and 
 strong bars are cast five or six inches square (and sometimes 
 more), which are laid in the pit and bedded previous to the 
 plate being laid upon them. These bars are laid at regular 
 intervals, the size of the mould and the opinion of the 
 moulder determining their number. They also form a back- 
 bone to the plate above them, hence there is no necessity for 
 the plate being extra strong ; a thickness of two inches is 
 quite enough for the heaviest casting. 
 
 The whole mass is bound from these bottom bars to bars 
 running parallel with them above the top plate of the moidd, 
 the top ones being much stronger than those below the plate, 
 the latter having the support of hard-rammed sand. A mould 
 of this kind is dried in the pit where it has been built. 
 
 We will not specify many particular forms of a loam-moulc^ , 
 but confine ourselves to general remarks on some of the prin- 
 cipal items connected with this branch. And seeing that 
 this kind of moulding is so closely allied to marine engine 
 work, Ave cannot do better than take as an example a bed- 
 plate, or condenser, with pumps, hot well, and columns 
 attached thereto. In this case the moulder first considers the 
 formation of the pattern which is to form the bottom part of 
 his mould, and whether a complete level surface can be made. 
 When the bottom part is of irregular construction, level parts 
 can only be made at intervals to suit, so that the pattern may 
 rest fair and not be twisted. In any case two courses of 
 
104 
 
 A TREATISE ON 
 
 bricks, with an incli of facing loam, usually intervene be- 
 tween the plate and the pattern. 
 
 When the mould is built with rough iron-sand the first 
 course of bricks is kept wide in the joints, say an inch and a 
 half, and the spaces are filled with ashes. The bricks in the 
 second course are built in the ordinary manner, t.e.^ inch 
 joints, these are filled with common loam, and the facing loam 
 is then put on. When, however, the bed or bottom part of 
 the mould is made with Erith loam, the second course of 
 bricks is treated in the same way as the first, that is, wide 
 joints and ashes, with the addition of straw or hay profusely 
 scattered previous to the facing loam being put on. 
 
 When a complete level bed can be made the pattern may 
 be laid on when the loam is soft ; but when only a part or 
 parts of a bed can be made they must be partially dialed with 
 fire-lamps, so that the pattern may rest upon without sinking 
 into the loam. 
 
 The moulder may be obliged to separate the outside of his 
 mould into many pieces for the purpose of getting the 
 pattern, or what is remaining of it, taken out, and for finish- 
 ing the different parts ; these are termed drawbacks ; " but 
 the more he can keep his mould together the better, as in 
 that case fewer jomts are made, the mould is stronger, more 
 ^ble to resist the pressure of the metal, and takes up less 
 room, when parted, on the foundry floor, a matter of some 
 importance when the shop is busy. When the moulder 
 must have drawbacks it is necessary that the different 
 partings should be carefully made and stiffened with hot 
 bricks or sand, so that they may retain their proper forma- 
 tion during the building of the other parts. The loam upon 
 which the drawback-plate Vi to be laid should be as stiff as is 
 compatible with facility of working. The plate, with its 
 prods or dabbers, mast be clean, i. free from sand, and no 
 more clay- water than is necessary should be put upon the 
 
IRON FOUNDING. 
 
 plate, as too much softens the loam. Corners which the- 
 plate does not reach closely enough should be carefully ironed 
 with three-eighths or half -inch pieces of rod-iron, and the^ 
 j)late should have plenty of holes in it, so that the loam ma}^ 
 rise up in them, thus giving the loam an extra hold of the 
 plate. When proper attention is paid to these details a good 
 parting is insured, which makes a speedy and perfect closure. 
 Again, core-irons in a loam mould should not be less than an 
 inch-and-a-half clear of the pattern all round, and carefully 
 packed in the wet loam with dried loam or pieces of brick. 
 In many cases it happens that the heat applied to harden the 
 mould does not reach some of the cores. This packing of the 
 core-irons is to the loam-moulder what the ramming of irons 
 is to the sand-moulder. A little time spent on the packing of 
 core-irons in the heart of a mould is not lost, since the mould 
 can do with less heat ; the pattern not being thus endangered, 
 the cores come out clean, and there are no broken-down parts 
 about them ; and when they come to be put in their respective 
 places, after the mould is dried and ready for closing, the 
 thicknesses will be all correct. If the moulder fails to do 
 this, either through undue haste or carelessness, the result is 
 sure to be a bad lift with all his cores, requiring them to be 
 mended up, and it takes more time to do this than to treat 
 them properly in the pattern. Unequal thickness is the 
 result of being either too thick or too thin, parts of the cores 
 having to be rubbed off, or, when thicker than they should 
 be, allowed to pass, possibly to the detriment of the casting ; 
 besides, it takes one-half longer time to put the mould 
 together under the circumstances we have just mentioned. 
 
 lEEEGULAE BUILDING OF A MOULD. 
 
 In building a loam-mould, of whatever construction it may 
 be, two important things ought to be borne in mind by the 
 moulder ; first, the mould lAUst be built so that it may require 
 
100. 
 
 A TREATISE ON 
 
 as little drying as possible ; second, a uniform or regular 
 thickness of loam must be kept on tbe face of the bricks next 
 the casting, which loam is never to be more th-an three- 
 quarters of an inch in thickness. 
 
 If we consider the moulder building against a pattern, and 
 using an extra quantity of loam to bed the bricks, each brick 
 that he lays down presses out the one that was laid previously ; 
 the second course presses out some of the bricks of the first, 
 as they have not stiffened properly in their places, and when 
 the pattern is drawn the surface of the mould will be found 
 to be covered with hollows. 
 
 Again, if we consider a mould made without a pattern, 
 the formation of the mould being made with a board cut to 
 the desired shape, and the bricks having in many places to be 
 kept back from the edge of the board, say two inches, such a 
 mould will be full of cracks, and we have already shewn what 
 cracks in the loam do to the casting ; besides, the moulder has to 
 ^ait till the first coating of loam is stiff before he can put on 
 the fine loam to finish with, and when the mould is irregularly 
 built time is wasted in waiting. In irregular building it is 
 just as likely that some parts of the mould may have too 
 little loam on the face of the bricks, and this is a more serious 
 evil than too much. 
 
 Let us suppose the case of a large sugar or chemical pan, 
 cast convex side up, in which some of the bricks that form the 
 core of the mould have only three-eighths of an inch of loam 
 on their surface. In this case the casting runs a great risk 
 of being scabbed on those parts where the loam is s^Dare, 
 simply from the want of a body to make it cohere with the 
 joints of loam between the bricks. 
 
 When metal falls from a height into a large mould, and 
 some of the bricks on the face of the mould have but little 
 loam, scabbing is sure to follow, unless the loam is extraor- 
 dinarily good. 
 
IRON FOUNDING, 
 
 "Wilen metal is to fall upon tlie bed or face ot mouiatnec* 
 loam covering the bricks ought to be regular. Whem^i^^i^^., 
 is a sheet of good loam, three quarters or seven-eighths~ of ' aur"^ 
 inch thick, properly dried and cast while it retains a little of 
 its heat, it is impossible for a scab to be produced on the 
 casting. 
 
 The sides of a mould are less liable to scab from irregular 
 building than the bottom or face, but veins are produced. 
 
 The mould should be built regularly on the outside as well 
 as the inside, the building-plates or rings not to be further 
 projecting than the brick- work, and care to be taken that all 
 vent-jpipes and fastenings for cores are not flush with the 
 building, as they may inadvertently be made loose in being 
 struck with a rammer whilst the mould is being rammed, or 
 when the mould is not rammed they are liable to accidents. 
 
 Loam-moulding is singularly adapted to all kinds of cylin- 
 drical bodies, as imder this method the mould can be swept 
 up with a board cut exactly as the outside formation of the 
 casting requires. This board is fixed upon an arm coming 
 from an upright bar, termed a spindle." Two or more 
 arms as the case may be, may be put on the spindle, which 
 revolves in a cast-iron socket, and the arms (sometimes called 
 
 shear-irons") are made to slide up or down the spindle. 
 The mould when large is built in a pit, a strong plank or 
 beam stretching over the pit, and having upon it a bush the 
 proper size of the spindle, which is usually three inches in 
 diameter, for the purpose of keeping the top of the spindle 
 steady. 
 
 FINISHING THE MOULD. 
 
 All loam-moulds or cores made from a board are, after 
 being built up, what is termed ''roughed up;" that is, the 
 loam is put upon the face of the bricks, and the board is 
 worked backwards and forwards until the whole mould has 
 
i08 
 
 A TREATISE ON 
 
 been covered with loam. When iron -sand loam is used it is 
 rough work indeed. After standing some time, and when the 
 board has been made perfectly clean, the loam is ^ ^ skinned 
 up.'^ "WTien skinned up with iron-sand, or the rough loam 
 already spoken of, the sand is sometimes riddled fine before 
 it is passed into the mill, or the rough-made loam may be 
 passed through a fine riddle, many foundries preferring the 
 latter plan to the former. When the mould is made with 
 Erith loam it is so fine of itself that an extraordinarily fine 
 surface can be brought on the face of the core or mould 
 merely by making the loam soft with water. The board has 
 a bevelled edge, and is kept going one way, the bevel leading. 
 A mould or cores built or made with Erith loam are always 
 finished when still green, with steel tools ; loam is easily 
 fijiished, as great liberty may be taken with it. After being 
 dried — and it can stand gi-eat heat, even to being bui^nt, with 
 comparative impunity — it receives its finishing touches by 
 being rubbed all over with a fine card, when it may be con- 
 sidered ready for the black- wash. It is very difficult to sleek 
 this, on the loam, as it has an inclination to stick to the tools. 
 Many foundi^ies do not sleek their moulds, merely rubbing 
 the blacking parts gently with the hand, or coming over 
 the part with a soft dry brush. 
 
 Iron-sand loam is finished after being dried, but, unlike 
 the Erith loam, it is liable to scab when it is burnt. ^"Tien 
 it has not been skinned up with a board it has to be rubbed 
 all over with coarse carding, then finished with water, fine 
 loam, and finishing-sticks made to suit the different parts of 
 the mould. This is termed dressing the mould.'' It takes 
 a long time in many instances, and sometimes much mischief 
 occurs to the casting from imperfect dressing, and the less 
 that a mould receives of the dressing-stick the better ; hence 
 the greater need for moulds being swept with a board instead 
 of being built against a pattern, as dressing is not req^uired 
 
IRON FOUNDING. 
 
 109 
 
 when a board has been used. The mould being dressed and 
 cold is now ready for the black- wash, and, unlike the Erith 
 loam-mould, steel or cast-iron tools to sleek the blacking can 
 be used upon it with almost absolute impunity. The loam- 
 mould bears the same relation to the dry-sand as the dry-sand 
 does to the green-sand as regards the freedom that may be 
 taken with it in putting it together. It is strong, and capable 
 of suffering a great deal o rough usage even after it has 
 been finished. 
 
 CASTINGS EENT OE SPEUNG. 
 
 It is seldom that a green-sand casting is cracked, in fact we 
 may say that we have never known such a case. Dry-sand 
 castings, on the other hand, sometimes crack, and loam cast- 
 ings often. A rent-casting may be caused by, and arises 
 principally from, three things ; fii'st, its formation ; sec )iid, 
 the metal ; and third, the manner in which the mould has 
 been built. AVith the formation or shape of the casting the 
 moulder has notliing to do ; but he has to do with the metal 
 and his mould. He knows that his casting must contract in 
 cooling, and if the mould is built strongly and is incapable of 
 yielding to the contraction of the metal, the metal (or casting) 
 must yield to the mould ; one of the two must give way. 
 In order, then, to allow the mould to yield, the core-irons 
 ought to have a large amount of clearance from the casting, 
 especially when it is large. We have spoken of an inch-and- 
 a-half of clearance space, but that should only be in small 
 castings ; in large ones the clearance should be nothing less 
 than two-and-a-half inches. Again, bricks made of dried 
 loam should be freely used in making the cores where the 
 contraction is great. It is sometimes requisite to build all 
 the cores entirely of loam brick, and to put the same material 
 in many parts of the outside of the mould, such as between 
 brackets, flanges, snugs, &c. Any casting of an inch in 
 
 I 
 
110 
 
 A TREATISE OS 
 
 thickness, and of good metal, should be quite capable of over- 
 coming the resistance of a mould built with plenty of loam 
 bricks, and with ample clearance in the core-irons. 
 
 We may here mention another preventative ; the top of a 
 casting should be a quarter-of-an-inch thicker than the sides, 
 either in dry-sand or loam, the reason being that the metal 
 on the top is not quite so strong and sound as in any other 
 part of the casting, and two causes are at work preventing 
 this from being the case ; first, there is less pressure on the 
 top than anywhere else ; second, the dust and particles of 
 blacking and loam float to the surface of the mould, and 
 become incorporated with the metal, causing it to be weak. 
 For instance, if we cast an open plate on a bed of sand, say 
 twelve feet by six feet, and two inches thick, and during the 
 time of casting an irruption takes place from some cause, and 
 the metal will not lie at peace — it dances and bubbles as long 
 as it has life — the face of the plate is extensively scabbed — 
 the sand has left its bed to the depth of half-an-inch, possibly 
 more in some places. In nine cases out of ten, when the 
 plate has cooled it will be found to be cracked in the centre ; 
 an extensive rent of about four feet may be seen there, the 
 outside remaining quite sound. The cause of this is easily 
 seen — the sand in the centre of the mould has mixed freely 
 with the metal, preventing the cohesive particles from coming 
 together, and in cooling a portion of it parts from the rest. 
 It is customary for smiths who are about to weld two pieces of 
 iron together to throw sand into the fire when the iron is nearly 
 at welding heat ; this is done simply for the purpose of 
 causing the silica or cinder to run off the piece of iron about 
 to be joined to another. The smith takes care that no sand 
 is left on his iron, else an imperfect weld is the result. So it 
 is with the plate of cast-iron on the bed, and also with the 
 top of a casting in which there is a large sui'face. Again, 
 the top of a casting cools much sooner than the sides or 
 
IRON FOUNDING. 
 
 Ill 
 
 bottom parts, and this of itself calls for the top of all 
 loam castings being made thicker than the sides or bottom 
 parts. 
 
 Twenty years since core-irons in loam-moulds were made 
 very strong, and generally cast in the same manner as plates, 
 sometimes so thick as to cause the cleaner to break the cast- 
 ings in the attempt to get them out ; the cleaner could 
 not be blamed for this, as the plates were often found 
 to be one-half thicker than the casting ; but no such thing as 
 plates are made for core-irons now-a-days unless in very 
 exceptional cases — when they can come out of the casting 
 without requiring to be broken. All core-irons are now 
 made as gratings, easy to be broken, and cast as lightly as 
 possible compatibly with the power to carry the core without 
 giving signs of yielding. In some foundries the plan of 
 easing or slackening the mould soon after being cast prevails 
 to a large extent. Now we do not believe in the expediency 
 of exposing a red-hot casting for this purpose unless under 
 very exceptional circumstances ; in fact, we scarceh' approve 
 of it at all ; for we have known more harm to result from 
 exposing a part or parts of a casting to be eased for contrac- 
 tion than we ever knew to occur when it was left to cool 
 slowly in the mould, assuming the mould to be made for the 
 casting to contract, and the metal good. There are doubtless 
 castings that must be eased, such as large condensers (and 
 the less even they are exposed the better,) and large columns 
 or cylinders for bridge work or colliery shafts. These have 
 to be eased because in their case the core may be said to be 
 an iron core, covered with two inches of loam. This iron 
 core is cast in segments, one of which is V-shaped, so as to be 
 easily drawn in, and the rest of the segments foUow. A 
 foundry on the T^Tie casts two of these in the week, eighteen 
 feet in diameter, seven feet deep, and twelve tons in weight. 
 In this ease the casting must be eased, and the iron core with 
 
112 
 
 A TREATISE ON 
 
 its coating suits the purpose well ; but this is a speciality, 
 and arrangements are made to suit it. 
 
 Some foundries slacken all their cylinders for marine work, 
 or land engines. This we consider to be a great mistake. 
 It is some years since the writer saw the folly of such a 
 practice. He once wrought in a shop where every cylinder 
 had to be turned on its side the day after being cast. The 
 main core was then taken out, and the core in the steam-chest 
 partiall}' removed. As the result one cylinder was cast too 
 hea^vw for the crane to turn it over ; it had to cool without 
 being eased, and no harm came of it. We reasoned, then, 
 that if a large casting could cool in its mould and no harm 
 take place, so could a small one. Again, what further con- 
 vinced us of the impolicy of exposing hot castings was this — 
 There came to a shop where we once wrought a c^dinder 
 pattern for a marine engine ; no time was to be lost in making 
 it, as it had been previously three times badly made in two 
 different foundi^ies. We learned that it had cracked in each 
 case, although it had been carefully eased on the day follow- 
 ing the process of easting. It was, therefore, decided in our 
 foundry not to ease it at all — give the core-irons plenty of 
 clearance — use plenty of loam bricks in the cores, and let the 
 cylinder stand for a week after being cast. The result was a 
 great success. We have acted on that plan ever since, and 
 believe it to be the right one. The above-mentioned casting, 
 we' may note, was upwards of fen tons in Aveight. 
 
 CLOSING THE MOULD. 
 
 The moulder in charge of a loam-mould should look for- 
 wa^l to the day on which he intends to begin putting his 
 moiild together — see that all his small cores are prepared, 
 that the chaplets which he may need are all ready to lay his 
 haads upon, as well as tubes for his vents, bolts and washers 
 to secure his cores, and a thickness-stick by which to set them. 
 
IRON FOUNDING. 
 
 18 
 
 If lie has all these smaller things ready there will be no fear 
 for the larger ones. 
 
 The duties of a chargeman on the day of closing are very 
 important ; first, he should not be absent on the morning 
 when he has to close ; he should be seldom or never away from 
 the mould during the day, so as to ensure that everything 
 is at hand and ready ; he should note carefully all the thick- 
 nesses — see every core resting properly — notice particularly 
 that no crushes of the mould in any part take place — himself 
 make up all important vents — if a core does not suit well be 
 quick in deciding what is to be done with it, and never cause 
 a core to be slung on the crane unless he is quite ready to 
 lower it in its place at once, as some one else may require 
 the crane. When a core requires to be altered, either by 
 rubbing a piece off or putting more material on, lower it 
 off the crane, whether any other person may be wanting the 
 latter or not ; if no one wants the crane cause another core to 
 be slung up, and go on with the closing. See that the labourer 
 has always plenty of hot plates in a fii'e close at hand, so 
 that handles, or rather holes in the core, caused by the lifters, 
 may be dried at once when made up. These things, if 
 strictly attended to, must cause the mould to be speedily put 
 together, which is the life of a casting, in whatever loam it 
 may be made. We may say, further, that if the chargeman 
 has any doubt about anything he should act at once, so that 
 no doubt shall remain ; if he is not sure of something, then 
 he should make it sure ; doing so may save him many diffic- 
 ulties afterwards. 
 
 AVhere ordinary chaplets are required to rest cores upon 
 great care must be taken to see that none of them are too 
 full in size, as the weight of the core, or the binding that 
 follows, may cause one of them to crush a portion of the core, 
 causing at once a bad casting ; and the same careful 
 watching must be observed in using chaplets as is requisite 
 
114 
 
 A TREATISE ON 
 
 to keep down cores. To find the proper thickness on the top 
 of a core, that is, the thickness intervening between it and 
 the top plate, it is customary to lay pieces of- clay on the top 
 of the cores, as many pieces, and on the proper places, as the 
 moulder or chargeman may in his discretion think fit. The 
 chaplets are then put on to the exact thickness of the clay. 
 Chaplets are made to advance in eighth parts in size. A\Tiere 
 ihey are found to be a sixteenth lower or thinner than the 
 clay, a slip of hoop iron the exact length of the chaplet is laid 
 below it. When the chaplet is a sixteenth-of-an-incli too 
 thick or too high it is rubbed down into the core until it suits 
 the clay. Many castings have been and are* lost from a 
 chaplet being too keenly set in the mould, the binding 
 together of the mould having completed the mischief by 
 causing a portion of the core to be crushed. 
 
 HAMMING LOAM MOULDS WITH SAND. 
 
 Should loam moulds be rammed up ? This question can 
 only be asked and answered from an economical point of 
 view. The ramming of the mould means the filling uj) with 
 sand of the space that intervenes between the outside of the 
 mould and the sides of the pit — generally two feet, this being 
 done by labourers. The sand is rammed with flat or dog- 
 rammers, and in courses of twelve inches deep at a time, until 
 the top of the mould is reached. When the casting is heavy 
 and the mould deep, the ramming must be made very hard, 
 care being taken that no rammer is allowed to strike any part 
 of the mould. Many foundries are in the habit of moulding 
 their heaviest castings, even up to the weight of twenty tons, 
 withou ramming ; but is it done as cheaply or as suc- 
 cessfully as it would be if ramming were resorted to ? 
 If we consider the extra provision and the elaborate appli- 
 ances which are requisite when moulds are not rammed to 
 sustain the j)ressui'e of metal and expansion of the mould by 
 
IRON FOUNDING. 
 
 115 
 
 heat, we must come to the conclusion that ramming up with 
 sand is the most natural and the cheapest method, except 
 in special cases, or where a great many castings are wanted 
 from one pattern ; then, indeed, it pays the moulder to pro- 
 vide proper mechanism and appliances to do it without the 
 aid of unskilled labour, and thus dispense with ramming. 
 
 A loam-mould that is to be rammed up with sand in a pit 
 has simply a plain building-plate three-quarters-of-an-inch 
 thick, on every three or four courses of bricks, and of the 
 breadth of the building, which is usually nine inches. This 
 is done to make the building strong and compact. A loam- 
 mould that is to be cast without ramming in the pit will have 
 a building-plate on every two coui'ses of bricks, made two 
 inches broader than the outside of the building, with flat 
 prods or dabbers cast on the outside edge of each, nine inches 
 in length, so that the building-plates will rest on each other. 
 In this way a strong iron cage surrounds the whole mould. 
 But this is not sufficient : the bottom plate upon which the 
 mould is built must be one-half stronger than the one that 
 is to be rammed up, and it must have large open snugs cast 
 at intervals of say two feet apart ; these square holes in the 
 snugs are to admit a strong cast-iron bar, say five inches 
 square ; the top plate covering the mould must have snugs 
 similar to the bottom ones, and like the bottom plate in 
 strength. When the mould is closed the bars are lowered 
 into the snugs, the bars passing through the bottom plate ; 
 cottars are then passed top and bottom through the bars, 
 holes in them being provided for the purpose, and the top 
 and bottom are in this way bound together. But the binding 
 of the mould is not even yet complete ; every building ring or 
 plate has to be carefully stayed opposite to the vertical bars ; 
 every joint in the mould must be covered with a plate made 
 for the purpose, and bedded with soft loam, and then stayed 
 from the bars. The binding bars on the top are clamped to 
 
llf) 
 
 A TREATISE ON 
 
 the top-plate snugs. It is this elaborate arrangement, neces- 
 sitating the use of an enormous quantity of east-iron for 
 binding purposes, that constitutes the principal objection to 
 moulds being cast mthout also being rammed. The danger 
 of losing the casting is elso great in such a case. When a 
 mould secured in this manner is filled with metal, should 
 there come forth the smallest running of iron from any place 
 that has not been properly secured it can seldom be stopped. 
 On the other hand, when the pit is rammed with sand, and 
 metal find its way out from a joint, it seldom runs far. 
 We may say that the vents come more freely from a mould 
 that is not rammed with sand than from one that has been 
 so rammed. 
 
 A loam-mould being filled with liquid metal has something 
 else to contend with besides the actual pressure ; the bare 
 pressure may be only thirty lbs. on the square inch on 
 the lowest part, but the mould has also to withstand the 
 sudden expansion of the metal by heat, and that is in 
 nearly every case of gi^eater moment to the moulder than 
 the actual jDressure. As a proof of this, a mould never 
 gives way during the process of filling. But when it is filled 
 the ladle or ladles may be turned back to their right position, 
 the moulder may be about to thrust his feeding-rod into the 
 metal, the other men who have been assisting are about to 
 retire, thinking that all is right — when suddenly the earth 
 opens — a blue flame is emitted in a long line, quickly followed 
 by a thin sheet of liquid metal, and the mould is found to 
 have given way. Given way to what ? it may be asked. 
 Not to the pressure of metal, for it carried that safely 
 enough. What then was the cause ? The answer is, that the 
 mould was quite adequate to sustain the pressure of metal, 
 but could not withstand the expansive force of the heat. But 
 it may again be asked — Why do some foundi^es produce all 
 their castings — and heavy ones too — without ramming them 
 
IRON FOUNDING. 
 
 117 
 
 up with sand ? We answer, it is a custom in these parti- 
 cular foundries, owing to the belief that it can be done with 
 more economy than when labourers are employed to ram up 
 a pit. 
 
 We know there are many castings made in loam that can 
 be and are produced with perfect safety, and more cheaply, 
 without being rammed up, and these not specialities by any 
 means. Among them may be mentioned propellers, pipes, 
 columns, internal shells for cylinders, cylinder covers, pistons, 
 junk, and packing rings. These do not require such an 
 ■elaborate or expensive get-up as many other castings do 
 when they are not rammed. It may be said that to ram 
 up a mould you require more labourers than when the 
 mould is not rammed, and that therefore more expense is 
 entailed by the former method. Now, it is quite true that 
 more labourers are required to ram, but then they can be so 
 utilized as to be made to do what moulders paid double 
 their wages would require to do in lieu of ramming. Thus 
 the two methods are about equal as regards expense ; besides, 
 the labourers, when not ramming a mould, are spread over 
 the shop, keeping it in order, and furthering the onward 
 progress of moulds in many wiiys. Some employers imagine 
 that labourers are non-producers, and do not like them ; but 
 when we consider how much they can really save the moulder 
 by leaving him free to devote his whole attention to mould- 
 ing, we must confess that the labourer is * an acquisition, 
 provided always that no more of them are employed than are 
 really required. 
 
 We may notice here that loam-moulds which are made 
 with Erith loam are usually built with fire-clay bricks ; they 
 «uit this kind of loam better than common bricks, and we 
 believe they are more economical, standing the heat better, 
 and not breaking up into so much refuse as common clay 
 bricks do. Iron-sharp-sand loam clings better, and has a 
 
118 
 
 A TREATISE ON 
 
 closer affinity to cominoii clay bricks than any other kind, 
 the clay in the loam no doubt causing this ; hence, the com- 
 mon red clay bricks are used with this kind of loam. 
 
 MAKING THE HEADS. 
 
 Making up the heads or gutters to receive the metal from 
 the ladle, either in green-sand, dry-sand, or loam, is a most 
 important matter, more especially in the latter case, as the 
 heads are generally much more extensive in loam than in the 
 other two branches, owing to the castings being usually 
 larger. It often occurs that this part of the process of mould- 
 ing is done hurriedly ; indeed we may safely say that this is 
 so in nine cases out of twelve. It seems to be taken for 
 granted by most moulders that when the last part of the 
 mould is closed and hidden from sight little else remains to 
 be done. Bring the metal forward" is often the order 
 of the day, too frequently resulting in a scrimmage to 
 get the heads ready ; but anything hurriedly done is never 
 well done. AVhen a ladle of four tons or up to ten tons 
 is required to fill a mould with metal the basin should be 
 large and capacious, nothing less than three feet in width and 
 twelve inches at its outlet. It should be made of dried loam, 
 in preference to being of sand, as many good moulds have 
 been ruined by the heavy wash of the metal raising up the 
 sand that formed the bed of the basin. With a well-dried 
 loam basin this cannot occur. 
 
 The gutters that lead from the basin and are intended to 
 communicate with and connect all the little gates that are 
 attached to, or rather open into, the mould, should not be 
 less than nine inches deep, by six inches broad ; they should 
 be formed of good sand, free from scrap iron, and the bottom of 
 the gutters ought to be twelve inches above the casting. The 
 gutters should be so formed, or rather planned, that an equal 
 distribution of the metal leaving the basin may be had all 
 
IRON 1^0 UN DING. 
 
 119 
 
 over. For this purpose the basin ought to be set as near as 
 possible to the centre of the place where the gutters are to be 
 cut out. When this is not attended to many parts of the 
 gutters do not get enough of metal to supply the gates in 
 those parts, scum and dirt rushing in with the metal, while 
 other parts may be overflowing. The gutters should be as 
 clean as the inside of the mould they cover, carefully firmed 
 u^) with the hand, and with no loose sand on sides or bottom. 
 The flow-gates should be well protected from metal running 
 into them in case of an overflow, owing to the ladle being too 
 much turned, or (as is the case with some ladles) taking a 
 sudden lurch and thereby throwing more metal out than the 
 gates are adequate to take in. A little bank of sand three or 
 four inches round each flow-gate will protect them. The 
 character of a moulder, as far as his workmanship is con- 
 cerned, ^can always be known from his manner of forming his 
 heads and the pains he takes in securing their cleanness. 
 Many moulds have been well enough made, and yet the cast- 
 ing has been lost through imperfectly and hurriedly made-up 
 heads. Notably, castings that are to be turned or bored must 
 suffer from what we term a dirty cast, the natural result of 
 badly-made and dirty heads. The moulder should easily 
 know, from what his furnace can do, when his ladle or ladles 
 will be filled, and the metal should be subservient to the 
 mould, not the mould to the metal. Better that the mould 
 should be ready for half-a-day than that the metal should 
 wait in the ladles for half-an-hour. 
 
 THE COMPOSITION OF CA8T-IE0N. 
 
 Mr. Bloxham, the great authority on cast-iron, says : — 
 Carbon is invariably and indispensably associated with cast- 
 iron, so that the latter sometimes has been spoken of as a 
 carbide or carburet of iron | but this would convey the im- 
 pression that the whole of the iron present existed in chemical 
 
120 
 
 A TREATISE ON 
 
 combination with the carbon, exactly as in the oxide of iron 
 the whole of the iron is combined with ox^-gen ; whereas the 
 greater part of the iron in cast-iron is present in the uncom- 
 bined state, its properties being altered or modified by the 
 presence of the carbide of iron, or compound of carbon with 
 iron, which is diffused through the metal. But for the cir- 
 cumstance that the term " alloy" is conventionally restricted 
 to the substances formed by the alliance of metals with each 
 other, whilst carbon is a non-metallic body, cast-iron might 
 be appropriately designated an alloy of iron with carbon. 
 The proportion of carbon present in cast-iron varies in dif- 
 ferent samples, but it never amounts to five per cent., so that 
 the carbide of iron must be regarded as being in a state of 
 intimate mixture with metallic iron." 
 
 On examining the fracture of freshly-broken pig-iron it 
 will be found that some specimens have a silvery- white and 
 others a grey colour, caused by the presence of very minute 
 particles of carbon which are interspersed among the light- 
 coloured particles of the metal. This sample acted upon by 
 certain acids dissolves the iron, but leaves the carbon, whereas 
 in white cast iron, very little carbon is left." 
 
 When a sample of grey iron is melted the particles of 
 free carbon are dissolved by the liquid metal becoming chemi- 
 cally combined with a portion of the iron, and if the melted 
 mass be suddenly chilled by throwing water upon it, or by 
 running into a thick iron mould, the carbon does not separate 
 again, so that a mass of white iron is produced. It is more 
 difficidt to convert the white into the grey variety of cast-iron, 
 but this has been effected by exposing the melted metal to a 
 high temperature, and allowing it to cool slowly, when a 
 portion of the carbon separated from the iron, and the grey 
 variety of cast-iron was produced." 
 
 Every moulder knows that he can produce any desired 
 portion of his casting nearly white, and extremely hard and 
 
IRON FOUNDING. 
 
 121 
 
 brittle, by making use of the cliill ; for instance, the beads of 
 shot and shell, the faces of forge-hammers, &c. 
 
 Mr. Bloxham says further, that since in grey cast-iron a 
 smaller proportion of the iron is in combination with carbon 
 and more of it in the true metallic state, this variety would be 
 expected to exhibit more of the properties of metallic iron, 
 whilst white iron ought to present the characters of the 
 chemical compound of carbon with iron described above. 
 Accordingly the grey cast-iron is much softer than white iron, 
 and admits of being filed and turned, whereas the white iron 
 is so extremely hard that a file will scarcely touch it, and a 
 blow from a hammer which indents a pig of grey iron will 
 easily break one of white. The larger proportion of metallic 
 iron contained in the grey cast-iron causes it to require a 
 higher degree of heat before it begins to exhibit signs of 
 fusion ; but it is capable of becoming very liquid at a suffi- 
 ciently high temperature, so as to be easily run into moidds." 
 
 "White cast-iron, on the other hand, is softened at a rather 
 lower temperature, but does not flow well, assuming a greasy 
 or pasty consistence. It scintillates or throws off sparks, 
 tjommonly termed by moulders " jumpers," to a much greater 
 extent than grey iron, as it runs from the furnace. White 
 cast-iron is about a twentieth part heavier than the grey 
 variet}^, its average specific gravity being 7*5, whilst that of 
 grey is 7*1. The grey iron rusts more easily in air, and is 
 more readily acted upon by acids than white iron, which cir- 
 cumstance may be ascribed partly to its containing more iron 
 in an uncombined form, and partly to the acceleration of 
 chemical action caused by the voltaic disturbance excited 
 by the contact of the pai^^icles of carbon with the particles of 
 iron in the presence of the acid, which in the case of air is 
 carbonic acid." 
 
 White iron usually, but by no means invariably, con- 
 tains less carbon than grey iron. Mottled cast-iron is 
 
122 
 
 A TREATISE ON 
 
 composed of a mixture of the grey and white varieties in 
 varying proportions, the grey iron sometimes appearing in 
 specks like minute flowers upon a white ground, whilst in 
 other specimens the mass is composed of grey iron, and the 
 white iron appears in spots." 
 
 Bloxham says again that ' ^ the tenacity of cast-iron is found 
 to be increased by re-melting." On this point we differ from 
 him. He does not seem very clear on the reason why 
 it should be so : he only gives a probable cause. We hold 
 that cast-iron after the second melting loses its tenacity 
 and a great deal of its character for softness. We believe 
 that the frequent re-melting of cast-iron would ultimately 
 reduce it to white iron. However, Mr. Bloxham is evidently 
 fully conversant with the nature of cast-iron, and we will see 
 what he further says on this important subject — important 
 alike to the moulder and to the engineer. 
 
 Next to the carbon, silicon (or silicium) is the commonest 
 xind most abundant constituent of cast-iron, its quantity 
 varying from xaVoth part to nearly ijVth of the weight of the 
 metal, the proportion being higher in the grey than in the 
 white. The silicon appears to exist in a state of chemical 
 combination with the iron, and is derived from the silica in 
 the ore or in the fuel. Silica is a combination of silicon with 
 oxygen ; and when the latter is abstracted by the carbon at 
 the high temperature of the blast furnace the silicon enters 
 into combination with the iron. The presence of a large 
 proportion of silicon in cast-iron is generally regarded as 
 injurious to its quality, the strongest iron being that which con- 
 tains a small quantity of that element. Iron which has been 
 smelted with coke contains a larger proportion of silicon than 
 that smelted with charcoal ; and hot-blast iron contains more 
 than that smelted by cold-blast." 
 
 Manganese is seldom if ever absent from cast-iron, for it is 
 a metal which very nearly resembles iron in its chemical pro- 
 
IRON FOUNDING. 
 
 123 
 
 perties, and is commonly found in iron ores, so that the same 
 operation which reduces the iron in the blast furnace also 
 reduces the manganese, and this metal becomes allo3'ed or 
 intimately mixed with the melted iron. The manganese has 
 been found in the large proportion of -iVth of the weight of 
 cast-iron, but it seldom exceeds 4-u-th. The influence exerted 
 by manganese upon the character of east-iron is very decided, 
 tending to the production of the white variety, as it will not 
 let the carbon separate. White iron, therefore, contains the 
 largest proportion of manganese. It has been asserted that 
 the presence of manganese in iron ores encourages the pas- 
 sage of sulphur and silicon into the slag, thus reducing the 
 proportion of those injurious impurities in the metal." 
 
 Phosphorus occasionally forms between A-o-th and -6"crth 
 parts of the weight of cast-iron, but ivoth part is a common 
 proportion of phosphorus. It exists in chemical combination 
 with a portion of the metal as phosphide of iron contained in 
 the ore, and is derived either from phosphate of iron con- 
 tained in the ore, or from phosphate of lime, which is fre- 
 quently present in the limestone, employed as a flux, and 
 in minute quantity in the coal. These phosphates contain 
 phosphorus in a state of combination with oxygen, which is 
 abstracted by the carbon of the fuel in the blast-furnace, and 
 the phosphorus thus set free enters into combination with the 
 iron. So completely is the phosphorus taken up by the metal 
 that only traces of the element in the form of phosphates 
 are usually found in the slag from the blast-furnace. The 
 effects of phosphorus are to harden the cast-iron and to 
 increase its fusibility." 
 
 Sulphur, though almost invariably contained in cast-iron, 
 rarely forms as much as ^Vth of the weight. It may be 
 derived from iron p^T^ites contained in the ore, or in the coal. 
 The white varieties of cast-iron contain a larger proportion 
 of sulphur than the gre}^ and it is generally admitted that 
 
134 
 
 A TREATISE ON 
 
 the presence of sulphur diniinislies the strength of cast-iron 
 in a very high degree." 
 
 We append Mr. Bloxham's table, illustrating the general 
 composition of the three principal species of iron in use at 
 foundries : — 
 
 GREY. MOTTLED. VHITE. 
 
 Iron 90-24 89-31 89*86 
 
 Combined Carbon 1-02 1-79 2*46 
 
 Graphite 2-64 Ml 0-87 
 
 Silicon 3-06 2-17 M2 
 
 Sulphur M4 1-48 2-52 
 
 Phosphorus 0-39 1-17 0-91 
 
 Manganese 0-38 1*60 2-72' 
 
 This table may be of great interest to the moulder, and not 
 only to him, but to the engineer. Barely does it occur that 
 the moulder has the time or means and education to enable 
 him to pursue the study of, or even enquire into, the chemical 
 properties of the material which passes through his hands 
 every day in the shape of pig-iron. It may appear at first 
 sight strange, but is none the less true, that engineers as a 
 rule are equally ignorant with moulders of the component 
 parts of cast-iron. Many engineers could not tell the dif- 
 ference between No. 1 and Nos. 3 or 4, or cold-blast from hot, 
 yet cast-iron forms by far the greatest part of an engine. 
 
 Nos. 1, 2, and 3 are grey irons^ No. 1 being a shade darker 
 than the others, and shewing a more crystalline appearance on 
 the broken surface. No. 1 is principally used for fine castings, 
 as it becomes more liquid than any other, and can run castings 
 of the frailest and finest construction. Nos. 2, 3, and 4 are 
 used more for ordinary castings. When different brands of 
 No. 3 are mixed in proper proportions, a strong iron is pro- 
 duced, with a third of good clean scrap, but not wrought iron 
 scrap, as Bloxham says. We never knew wrought iron scrap 
 to be put in a cupola and melted with the cast iron ; the great 
 
IRON BOUNDING. 
 
 125 
 
 heat requisite for tlie melting of cast iron would in all pro- 
 bability entirely change tbe character of the wrought iron. 
 We have known of malleable turnings being put into the 
 ladle and melted there immediately before casting ; this being 
 done at the instigation of the engineer for whom the casting 
 was intended, but we could never learn that the casting was 
 any stronger for it ; but one thing we know, that it changes 
 the character of the metal very much, by making it lazy to 
 run ; consequently the casting incurs the risk of some part of 
 it being cold-shot. 
 
 Bloxham further says : — ^' The average tensile strain of 
 cast-iron is about seven tons per square inch. The general 
 brands of iron in use in foundries are Nos. 1, 2, and 3, some- 
 times 4 .and 8 for certain castings, No. 4 best grey forge iron, 
 and No. 5 grey forge : they do not become so liquid ^vhen 
 melted as 1, 2, and 3 ; but they are tougher and better fitted 
 for purposes where strength is required. No. 5 is also used 
 for the manufacture of wrought-iron, as is also No. 6, or 
 strong forge, which is still less grey in quality. No. 7 is 
 decidedly mottled iron, and No. 8 is white. Grey cast-iron is 
 usually regarded as the j)i'oper or normal product of a blast- 
 furnace in good working order, supplied with a due propor- 
 tion of fuel. If the quantity of fuel employed be too small 
 for the ore, so that the temperature is low, a white cast-iron 
 is produced, and a large pro^^ortion of iron is found in the 
 slag, to which it imparts a nearly black colour. The slag 
 from a furnace yielding white iron contains about five per 
 cent, of the metal, whilst the slag from grey seldom contains 
 more than two per cent." 
 
 When the proportion of sulphur in the fuel is large the 
 iron will tend to be white, unless a heavy charge of limestone 
 is used.'' 
 
 Cold-blast iron is stronger and purer than hot-blast, 
 being freer from sulphur and j)hosphorus, the temperature of 
 
 K 
 
120 
 
 A TREATISE ON 
 
 the cold-blast not being adequate to melt the same kind of 
 charges that are put into the hot-blast. Cold-blast iron is 
 usually melted from ore only, whereas in the hot-blast it is 
 not uncommon to use one-fourth of the charge from cinder- 
 iron, taken from the puddling-furnace, this producing sulphur 
 and phosphorus." 
 
 The different kinds of iron present different phenomena in 
 flowing out of the furnace, more decided from the smelting 
 furnace than from the cupola, but still the same, only in a 
 lesser degree. The moulder will have noticed that when 
 No. 1 or grey iron is running from the cupola into the ladle 
 very few sparks are thrown off, and those only fall as 
 ordinary sparks. Yery different are the sparks or jumpers 
 that are thrown off from No. 4. In the fii'st place, there are 
 four times more, the greater number arising from a cause 
 quite different from that which exists in the former case. 
 Tomlinson explains this in the following words : — From all 
 parts of the fluid surface is thrown off a vast number of 
 metallic sparks, from the absence of carbon, which renders 
 the metal sensitive to the oxidising influence of the atmos- 
 pheric air. Small spherules of iron are ejected from all parts 
 of the surface to the height of five or six feet, and sometimes 
 higher, when they inflame and separate with a slight hissing 
 noise or explosion into a great many particles of brilliant fire, 
 forming oxide of iron." 
 
 No. 4 iron when in the ladle shews a greasy appearance, 
 with scarcely a break on the surface, whilst the act of raking 
 the rubbish off it sej)arates it, as it were, into long cuts, as if it 
 had a scum on the top, presenting a dull and lazy appear- 
 ance. When small castings for engine work are made with 
 this iron, on the surface of the castings being planed or 
 turned, they will seem as if worms had been making their 
 bed in the metal, the latter being full of .clear worm- 
 holes. 
 
IRON FOUNDING. 
 
 127 
 
 No. 1, on the other hand, presents quite a diferent aspect 
 in the ladle. Mr. Miishet describes it thus : — Millions of 
 the finest undulations move upon the surface, displaying the 
 greatest nicety and rapidity of movement, conjoined with an 
 uncommonly beautiful variation of colour, which language is 
 inadequate justly to describe. Such metal in quantity will 
 remain fluid for twenty minutes after it is run from the fur- 
 nace, and when cold will have its surface covered with the 
 beautiful carburet of iron already mentioned, of an uncom- 
 monly rich and brilliant appearance." It should be under- 
 stood that Mr. Mushet is here speaking of the appearance 
 presented by the iron on its coming from the smelting fur- 
 nace, although it presents exactly the same ajipearance when 
 run from the cupola. In the ladle every moulder can easily 
 distinguish No. 1 from No. 3. 
 
 The appearance of No. 2 and No. 3 in a state of fusion pre- 
 sents some of the phenomena both of No. 1 and of No. 4. 
 The slag from No. 3 or No. 4 is slightly different from that 
 of No. 1, or fine grey. In cupolas in which slag-holes are 
 used the difference will very often be noticed in the following 
 manner : — In No. 3 or No. 4, after the cujDola has discharged 
 nearly all its slag, the blast will impel the remainder with 
 •such velocity as to blow the slag into minute fibres smaller 
 than the most ductile thread, or rather wire. At first these 
 float upon the air like wool, and when at rest they very much 
 resemble that substance. This never takes place with No. 1 
 or fine iron. 
 
 These remarks on cast-iron are fully borne out by Tomlin- 
 son in his Cyclopoedia of Useful Arts, by Percy's Metallurgy ^ 
 and by Bloxham On Cast Iron, 
 
 We shall now specify a few mixtures of different kinds of 
 iron for various castings, as we have seen them proved in 
 actual practice. 
 
128 
 
 .4 TREATISE ON 
 
 MIXTUEES OF CAST lEON FOE CEETAIN KINDS 
 OF CASTINGS. 
 
 A good tough, iron for locomotive cylinders may be tlius 
 composed : — No. 4 Pontypool "Welsh cold-blast, one-half ; 
 No. 4 Clyde, one-half ; melted and cast into pigs for the 
 purpose of being properly mixed. If the c^dinders are above 
 an inch thick, mix two parts of No. 4 Clyde with one part of 
 No. 4 Pontypool. 
 
 For ordinarj' mraine cylinders No. 3 Clyde, Coltness, Sum- 
 merlee, and Monldand, equal parts, with five cwt. of good 
 clean scrap to the ton ; if no scrap, about four cwt. to the 
 ton of No. 4 Clyde, which makes a good close and tough 
 iron. When plenty of good clean scrap can be had, the 
 following alternative mixture will be found equally good, 
 and will melt more quickly : — Seven cwt. of Summerlee, 
 Grartsherrie, and Carnbroe, equal parts, four cwt. of Weardale 
 or Middlesbro*, and nine cwt. of scrap. This mixture does 
 well enough for bed-plates. For propellers one part of 
 hematite No. 4 and two parts of as many brands of No. 3 as 
 possible, say the r^ame as last, or two parts of good clean 
 scrap, make an extremely tough iron, one inch square bar of 
 iron, three feet in length bearing, breaking at eight-and- 
 half cwt., -Hrths deflection. 
 
 Anvils and hammers for forges : — Five c^-t. No. 4 Ponty- 
 pool, five cwt. No. 3 hematite, five cwt. No. 4 Clyde, and 
 five cwt. Monkland white or No. 8. This mixture is 
 extremely tough and very hard. 
 
 Light work, not ornamental : — Thi^ee or four brands of 
 No. 3 G. ^L. B, and about five cwt. to the ton of No. 1 Gart- 
 sherrie or Coltness. 
 
 Internal shells for H. P. cylinders : — Three cwt. of white, 
 three of Summerlee, and two of Middlesbro', to the ton, the 
 
IRON FOUNDING J y p 7 ^ i l 
 
 ^ Li i .1.. ; j,.)^m:T 
 
 rest good clean hard scrap, cast into pigs, the ' &ii^%^^,^^e 
 
 locomotive mixture ; if no scrap, four cwt. of white to sixteen 
 cwt. of mixed brands No. 3. 
 
 Another good mixture for ordinary green-sand castings, 
 and when the scrap is good and plentiful, is : — Four cwt. of 
 Scotch M. B, six cwt. of Wcardale, and ten cwt. of scrap. 
 "When the scrap is good, such as old engine iron, or used-up 
 plates from foundries, this mixture will be found noo to be 
 far behind any of those previously quoted. It will bear a 
 strpvin of 7^ cwt. on a three-feet bar one inch square 
 iJths deflection. 
 
 Like many other things, the cupola has undergone a 
 great many changes Avithin the last twenty years. A good 
 quicldy-melting cupola is of great importance to the moulder 
 as upon it depends in a great measure the success of many 
 important castings. Foundries have also extended in the 
 matters of number and size, improved forms, and steam or 
 hydraulic cranes ; all to meet the increased demand for cast- 
 ings of a heavy class, so that naturally the cupola, being of 
 such importance in the foundry, has come in for its share of 
 improvement. A moulder is proud of his cupola if it is a 
 good one, and when a stranger comes into the foundry the 
 moulder will not be long in shewing the cupola to him, 
 pointing to it with pardonable pride, and saying, ' ^ That is 
 our cupola, we melt so many tons in an hour with so much 
 coke and so many oimces of pressure." We never yet went 
 into a foundry without being shewn the cupola, and had to 
 to listen to the story of its qualifications. When a moulder 
 knows that his cupola can supply him on demand with twenty 
 tons of metal in good condition to cast in one casting without 
 any or little trouble, he has some reason to be proud of it. 
 
 THE CUPOLA AND AIE FUENACE. 
 
180 
 
 A TREATISE ON 
 
 Although, cupolas have been improved, the principle remains 
 the same as it existed in the days of Tubal-Cain. In India and 
 Asia, at the present day, the natives ma}- be seen on the road- 
 side working at a charcoal fire below a rudely-made crucible, 
 and a still more rudely-made paii^ of bellows which have been 
 manufactui-ed from some beast's skin, blowing away and 
 melting metal. That is their cupola, and they can barely melt 
 ten ounces in an hour. We can melt upwards of ten tons in 
 the same time, but the ^^rinciple is the same in both cases. 
 
 CUPOLAS. 
 
 The early cujoolas in this country were of a rectangular 
 shape ; then followed the round form, which is still retained. 
 The first round cupolas were very short and wide, deriving 
 the blast from common fans ; the distance from the bottom to 
 the tuyere did not exceed two feet ; they seem to have had 
 two rows of tuyeres, the top one about twelve inches from the 
 under, the intention of this being to stop up the lower tuyeres 
 when the metal appeared, and to blow from the top ones. 
 The distance from these to the top, or rather to the charging 
 door, was four or five feet. 
 
 But strong and brisk competition in foundries demanded a 
 change, and the problem to solve was the invention of a 
 cupola that would melt quickly with the least consumption of 
 fuel. This resulted, as S^^retson says in his Casting and 
 Founding,''^ in the invention of five different formations of 
 cupola, namely, Kirkgar's (German) ; Mackenzie's (much in 
 vogue in America, as the anthracite coal suits it best) ; 
 Ireland's ; Woodward's steam-jet, and Voisin's. 
 
 The best of these, in oiu^ opinion, is the Kirkgar cupola, 
 its interior formation being best adapted for melting a large 
 quantity of metal. Spretson gives the dimensions of such a 
 cupola as follows : — 
 
IRON FOUNDING. 
 
 131 
 
 feet in. 
 
 Diameter at hearth 3 3 
 
 charging door . . . . ^ . . 3 0 
 
 top of chimney 2 6 
 
 Height from base-sill to charging door 7 0 
 
 from door-sill to top of chimney 16 0 
 It will be seen from the above that this cupola is larger at 
 the base than at any other part, slightly tapering to the 
 charging door, so as, in a great measure, to prevent the 
 charges hanging above the tuyeres. The other descriptions 
 of cupolas given by Spretson are, in our o^Dinion, calculated 
 to encourage the charge to hang, being narrow from the base 
 up to a little above the tuyeres, then getting wider up to the 
 charging door. Of course the object in cupolas of this forma- 
 tion is to save fuel before charging with iron ; but we think 
 the advantage thus gained is not to be compared with the 
 disadvantage of the trouble and risk involved in hanging 
 and scaffolding. The latter must take place in cupolas of 
 this formation to a greater or lesser extent at the end of two 
 hours' blowing, and the avoidance of scaffolding in a cupola 
 is a most important desideratum. AVe may here explain the 
 cause and effects of scaffolding, which we hold takes place, as 
 a natural consequence, in every cupola, more or less, of what- 
 ever formation. 
 
 AVe will suppose a cupola to be charged with pig-iron and 
 clean scrap, or wholly with pig-iron ; the blast is put on ; in 
 ten or fifteen minutes the metal will be seen, on looking in at 
 the tuyeres, to be dropping or running in little rills, the coke 
 close to the tuyeres being in a state of bright white heat, so 
 white indeed that a practised eye can only see the metal run- 
 ning. After an hour has passed, look in again at the tuyeres, 
 and something else than metal will be seen dropping and 
 running, that is slag. It will serve no useful purpose for us 
 to give the chemical properties of this slag, as it is well 
 
332 
 
 A TREATISE ON 
 
 known that the iron, lime, and coke all tend to form a body 
 known by the moulder as slag. The cold air rushing from 
 the tuyeres blows this slag on to the coke nearest the tuyere ; 
 the slag at once becomes black ; the metal running is blown 
 upon the black slag and immediately sets ; the coke that has 
 retained this slag and metal becomes cold, and more and more 
 is accumulated until the whole surface is black and cold. 
 This at first forms only a thin partition, as it were, between 
 the blast and the bright fuel, a light pricker easily breaking 
 it down and allowing free access to the air again ; but after 
 some hours, say four, it will be found to have become very 
 strong, so strong indeed that it will require a steel bar di^iyen 
 into it with considerable force to break it through ; then it 
 will be found to extend some distance towards the centre of 
 the cupola, and to have become a mass of cold coke, slag, and 
 metal. This taking place with three tuyeres in a cupola three 
 feet six inches in diameter may soon only leave a s2Dace of 
 eighteen inches clear in the centre. The furnace has then 
 become " scaffolded," and begins to melt very slowly, therefore 
 the sooner it is di^awn the better, a strong partition having 
 been formed between the blast and the charges. 
 
 We have spoken here of the worst kind of scaffolding ; 
 seldom does it occur in so bad a degree as this unless the 
 iron be very dirty, the coke dirty also, and the tuyeres not 
 properly seen to. However, as we have said already, there 
 is now no cupola in use which will not shew, at the end of 
 four hours' melting, more or less symptoms of threatening to 
 
 scaffold." We must, then, consider the best means to pre- 
 vent scaffolding." This, we have found, is to cease blowing 
 with one of the tuyeres, and build the tuyere up with chips 
 of brick and loam. In about a quarter -of -an-hour the sala- 
 mander will be found to have disappeared. Or, when the 
 tuyere is beginning to shew signs of getting black, a few 
 pieces of small coal pushed into the face of the tuyere will be 
 
IRON FOUNDING. 
 
 133 
 
 of much, service, if they can be got to catch, fire ; if not, the 
 coal is of no avail. Completely stopping up one of the tuyeres 
 in turn never fails, and the cupola can be kept in good order 
 for many hours. 
 
 The best form of cupola is, to some extent, a matter of 
 opinion. The view that we have formed is, after no small 
 "experience, that the cupola works best when parallel from the 
 bottom to the charging door. One of four feet diameter 
 should gradually close in from the charging door to the top 
 of the chimney to the diameter of three feet, and should not be 
 less in height from the bottom to the charging door than 
 thirteen or fourteen feet, and sixteen feet if appliances are 
 easily available for lifting the charge up to the stage. The 
 height of the chimney is of no importance so long as it is kept 
 clear of the foundry roof. 
 
 A cupola of this plain formation, with three tuyeres seven 
 inches diameter each, supplied with a blast pressure equal to 
 twelve inches of water, or eight ounces, will melt twenty-eight 
 tons of clean iron in four hours ; one-and- three-quarters cwt. 
 of good coke to each charge of twenty-three cwt. of iron. 
 
 A small cupola, eighteen inches diameter at the base, and 
 twenty-two inches at the charging door, twelve feet from the 
 base to the charging door, and two feet from the bottom, to 
 three tuyeres of tliree inches diameter each, will easily melt 
 -one ton per hour, the charges being forty lbs. of coke to 
 five cwt. of iron, one-third being pig-iron, the blast being the 
 same pressure as quoted above. 
 
 One of the same kind as the above, only six inches larger 
 in diameter, will easily melt one ton and a half in the hour, the 
 charge of iron being increased to seven cwt., with fort}^ lbs. 
 of coke, the same as the smaller one ; the metal from both 
 cupolas being quite adequate to run grate metal castings. 
 These results are equal to those of any cupolas of which we 
 know. 
 
A TREATISE ON 
 
 Woodward's steam -jet cupola acts veiy well ; but we do 
 not think that it will ever become popular. The inventor 
 claims for it a saving of fuel ; but from what we can learn^ — 
 and in one that we have seen in use — the saving is obtained 
 at the expense of slowness in melting and dulness in iron, 
 two very important considerations with regard to a cupola ; 
 possibly it had not been wrought exactly to the inventor's 
 idea. No blast is required for this cupola, the steam-jet in 
 the chimney being in its stead, so as to produce a sufficient 
 current or column of air. 
 
 Yoisin's cupola is distinguished by a falling bottom, after 
 the American plan, and by the manner he has arranged^ the 
 tuyeres, which we consider a good plan, in preventing to some 
 extent scaffolding." The falling bottom, we are inclined 
 to think, will never be much in use unless with small cupolas. 
 This cupola is narrow at the boshes, an arrangement we do 
 not like. The next trouble in connection with the cupola 
 forming carbonic oxide — commonly known as scaffolding" — 
 is the hanging of the charge ; sometimes, indeed, this tends 
 to produce the former evil. The furnace-man is much to 
 blame when a charge hangs, as he has caused the mischief 
 by either leaving projections of brick sticking out when 
 repairing the lining, or by carelessly throwing in the metal 
 when in the act of charging, the iron becoming wedged be- 
 tween the sides, the charge refusing to sink gradually as it 
 should do ; as the charges lower down gradually get melted, 
 a sudden fall of sometimes eighteen inches is thus caused. 
 Broken plates that have been used for loam work, with stout 
 long prods, inadvertently catching the rough sides of the 
 cupola, will easily cause the charge to hang ; but the man 
 who is charging should be alive to that danger, and endea- 
 vour to place his iron so as to prevent its catching the sides 
 or walls of the furnace. 
 
 Cupolas that have a belt running round them, for the blast 
 
IRON FOUNDING. 
 
 135 
 
 to enter at tlie tuyeres, ought to have a large sliding door 
 jprovided in the belt opposite the tuyere, nine inches by 
 twelve ; this door will enable the cupola-man to close up any 
 tuyere when necessary. A small spy-hole in the centre of the 
 door will enable the state of the tuyere to be ascertained at 
 any time without the slide being moved ; but when tuyeres 
 keep fairly clear of themselves we think it is best not to 
 touch them. 
 
 CHAEGING THE CUPOLA. 
 
 The cupola is generally lighted three hours before the 
 time appointed for blowing, as much coke being put in as 
 shall reach fifteen or eighteen inches above the tuyeres. 
 When the fire reaches the tuyeres and is fully developed, the 
 furnace can be charged with metal. Should there be an eddy 
 wind the fire may take an liour longer to kindle up to the 
 required height, and in that case the cupola (for that cast) 
 will not melt so quickly. A long chimney would tend greatly 
 to counteract the effects of a down-blowing or eddy wind. 
 The furnace-man is generally the best judge of the propor- 
 tionate weights of iron and coke that his cupola can properly 
 take for a charge. For cupolas in every-day use in ordinary 
 jobbing foundries the charge of iron is about twenty- 
 four cwt. of metal to one-and-a-half cwt. of good coke, one 
 large shovelful of lime being added at every second charge ; 
 more lime than this is apt to be injurious to the lining of the 
 furnace. Cupolas which melt all day are large, possibly five 
 feet or more in diameter, and require double the charge stated 
 above. 
 
 About two years ago some persons went about the country 
 professing to have found out a particularly economical method 
 of charging the cupola ; their system was to break each bar 
 of pig-iron into four pieces, build the pieces all round, the 
 
13G A TREATISE ON 
 
 ends close to the lining of tlie furnace, and till the space m 
 the centre with coke. Another person recommended a plan 
 exactly the reverse of this ; that is, the placing of the iron in 
 the centre, and the coke between the iron and the lining. 
 We may safely affirm that neither of these plans, after being 
 carefully tried, has ever given satisfaction, and this for two 
 reasons : — first, the difficulty of carr^dng it into execution ; 
 and second, after this difficulty had been surmounted the 
 metal was melted too slowly and also too dull. Founders 
 that have any pretensions to turn out good castings would not 
 be troubled to adopt such modes of charging ; in fact, it 
 would not pay. 
 
 After a careful trial of different methods we believe that 
 the plan of throwing the pig-iron and scrap-iron indiscri- 
 minately into the furnace, keeping as near as possible to the 
 centre, and placing the coke well to the outside, is really the 
 best method of charging a furnace. By this method we have 
 found a cupola melt iron more quicldy and in better condition, 
 with a man's charging who had never charged before, after 
 he got a simple lesson, than we have known to be the case 
 when any other system has been pursued. 
 
 FANS, OE BLOWEES. 
 
 Cupolas having undergone so many changes in their mode 
 of formation, the apparatus for producing the requisite supply 
 of air, or " blast," as it is commonly termed, has had to keep 
 pace with these alterations. We have now fans very much 
 improved from the old plain ones, and blowers and blowing- 
 engines. Schiele's fan is generally regarded as the most 
 improved now in use ; it was introduced in 1868. Eoot's 
 and Baker's blowers followed, each being supposed by dif- 
 ferent parties to be the best. Blowing engines are more in 
 use in America, our transatlantic cousins believing that they 
 
IRON FOUNDING. 
 
 137 
 
 ends clo se to the lin ing o f tlie ^ Jurngce^ and fill the space in 
 suit their anthracite coal best^ and such is the case. 
 
 ►Spretson gives a most elaborate and clear account, in his 
 Casting and Foimding, oi all the fans, blowers, and blowing 
 engines in use for cupolas. This description is well worthy 
 the moulder's attention. The writer seems to infer, (p. 138) 
 that when a cupola is not provided with a fan to produce the 
 proper amount of air, the following is the result: ^'As the 
 melting proceeds, the tuyeres become foul through the accu- 
 mulation of slag and cinders in the interior, to such an extent 
 that the melting ceases, and the iron is rapidly decarbonized, 
 loses its fluidity, and is rapidly chilled, so that the castings 
 are bad from being run short, too hard, or unworkable with 
 the tools which follow, and producing much waste." Now to 
 us this seems strange language, we mean the latter part. 
 The tuyeres may and do at times get foul, as Spretson says, 
 and the melting may almost cease in consequence, but what 
 has that to do with casting a mould short ? No moulder 
 would begin to pour metal into his mould without fully be- 
 lieving that he had the requisite quantity of iron in his ladle. 
 Castings are not run directly from the cupola, as Spretson 
 seems to imply. Again, the metal does not lose its fluidity, 
 and no change takes place in its character, even if the cupola 
 has been charged with No. 1 pig-iron. No. 1 iron will cer- 
 tainly run from it. The cuj)ola has become scaffolded," 
 and it would not pay to keep men waiting on their iron ; and 
 as the melting tends to get worse, that is, slower, the sooner 
 the cupola is drawn the better, as we have said before. On 
 page 140 of Spretson's work he says : — Seeing that 
 the highest pressure required is from twenty to twenty-four 
 ounces per square inch, it is impolitic to employ a fan whose 
 duty (highest) is sixteen ounces ; not that pressure is a sine 
 qua non for smelting in the cupola, but that in order to intro- 
 duce the necessary amount of oxygen per lb. of fuel the 
 
138 
 
 A TREATISE ON 
 
 internal resistance reach such a point as to cause a corres- 
 .^Wding increase in the density of the air." FeAV cupolas can 
 claim to have a pressure of blast up to twenty ounces. Xo 
 doubt an extra large one would require this, but we know of 
 no cupola that has it, so that we cannot say what e£Pect a 
 pressure reaching twenty ounces would have. A cupola in 
 Liverpool has two rows of small tuyeres (two inches in 
 diameter) immediately above four large ones of six inches 
 diameter, and we understand that good results are obtained 
 from this plan. 
 
 The blast coming from the fans or blowers should run 
 below the stove floor, as this tends to dry the air on its way 
 to the furnace ; and the fans should occupy- a diy 'place, 
 damp air being well known to be adverse to the melting of 
 iron. Various plans have been suggested to heat the air for 
 the cupola, and some of them have been tried, but none seem 
 to have produced the results desired. There is no doubt that 
 air heated to a high degree could be supplied for the cupola, 
 but the cost of the requisite heating apparatus would be such 
 that no foundry-master would adopt it. As the air should 
 enter the furnace dry, so should the coke be dry, and as free 
 as possible from sulphur. For this purpose a shed ought to 
 be provided for the coke, it being obvious that coke satu- 
 rated with water cannot be expected to give forth the heat 
 requisite to melt iron as soon as dry coke. 
 
 Before passing from the subject of cupolas, we may, in 
 conclusion, say, that as there are so many different shapes of 
 cupolas, and such varied kinds of apparatus to produce the 
 blast, it is difficulfc for any one to lay down a hard-and-fast 
 rule and say, this is the thing. The foundry-master, how- 
 ever, should carefully consider and search for the kind of 
 cupola that will best suit his special requirements, seeing that 
 upon a quick melting and an economical furnace depends in 
 a great measure the success of the foundry. 
 
^^^^ 
 
 IRON FOUNDING. <y^ 139rt>X 
 
 GATHERING METAL FOR LARGE CASTINGr|C|ri 
 
 EVILS IX HAVIXG TOO MiVXY LADLES. 
 
 A casting twenty tons in weight, no matter for what pur- 
 pose, requires twenty-three tons to be melted, and this 
 quantity two moderate-sized cupolas should be able to pro- 
 duce in good condition for casting in two-and-a-half hours, 
 with three ladles, say two that will carry ten tons each, and 
 one that will carry three tons. 
 
 To this mode of gathering metal, however, some objections 
 may be raised, and there are difficulties to be contended with. 
 First, it is argued, and with some reason, tliat the metal is 
 not properly mixed when in three ladles ; in fact, some engi- 
 neers specify that their castings shall not bo cast in this way, 
 the metal must be altogether ; and for special castings we 
 believe that such apian should be adopted. The next trouble 
 that besets the moulder is that sometimes the first filled ladle 
 soon begins to shew symtoms of becoming dull, or slug- 
 gish, before the other two are ready ; recourse must then be 
 had to the plan of putting extra covering upon it ; this is 
 usually done with saw-dust, smithy ashes, or dry blacking, 
 and covering the whole with thin sheet-iron plates. AVe 
 have seen this a very serious trouble, but happily it seldom 
 occurs ; the best — and we might say the only — way to avoid 
 such an evil is to be sure that the coating of loam in the 
 ladle is perfectly dry, and the ladle itself made hot. In order 
 to do this a large fire is usually made in the ladle three hours 
 before the metal is tapped into it from the fiu'nace ; the embers 
 or red ashes of the fire float upon the top of the metal, and 
 this of itself, under ordinary circumstances, ought to be a 
 sufficient protection to the metal for a considerable time in 
 any large ladle. 
 
 Supposing the three ladles to be now filled and brought 
 
140 
 
 A TREATISE ON 
 
 into position for casting, the rubbish and fire are raked off 
 eacli as quickly as possible ; if one ladle gets cleaned before 
 the other two it must wait until they are done, and it may 
 soon give signs of getting dull. The three being at last 
 ready, the casting or pouring begins. One ladle is rather 
 high, another is as much too low ; one ladle is too easy to 
 turn, and inclines to fall over to the extent of five or six 
 inches, thereby causing a great fiow of metal, and possibly 
 overflowing the gutter or head in a great wave of metal, 
 carrying dirt and sand into the flow-gates, and thence into 
 the casting ; another ladle may absolutely refuse to turn 
 after it has become half- empty, until more force is applied to 
 it ; the metal falling from the ladle that is too high has 
 disturbed the sand, causing a commotion by throwing showers 
 of sparks and metal all round, so that the men at that parti- 
 cular ladle are on the point of running from it, and sometimes 
 are actually compelled to do so ; add to this the calls of the 
 men at one ladle to the men at their crane to hoist ; the other 
 crane-men mistake it as being addressed to them, and they 
 hoist when they are not wanted to do so ; eventually, how- 
 ever, though amidst no small uproar, the mould is filled. 
 The result is a very imperfect casting, and if it must be clean 
 it has a poor chance of passing. This occurrence does not 
 happen often, but it does sometimes take place in casting 
 with three ladles, if all things are not carefully looked after. 
 But twenty-three tons of iron can easily be cast from three 
 ladles when the work is properly managed. First, it is 
 essential that the cupolas should be capable of producing the 
 metal in good condition ; second, that the ladles are in good 
 working order and hot ; third, that the metal is well covered 
 from the air ; fourth, that the mould is quite ready ; fifth, 
 that each ladle is properly manned ; sixth and last, that no 
 one directs except the foreman. If these conditions are 
 attended to there need be no fear of the casting. 
 
IRON FOUNDING. 
 
 141 
 
 METAL GATHEEED IN ONE LADLE. 
 
 When the metal required reaches the weight of thirty tons 
 or upwards, it is usual to provide a special ladle or reservoir 
 for the purpose ; this is done by two different methods. First, 
 a ladle may be made of cast-iron plates^ provision being made 
 in the shape of flanges for bolting the plates together octagon 
 shape ; a bottom plate one-and-a-half inches thick is bolted 
 to the eight side-plates, and the ladle is then ready to be 
 built up inside with bricks and loam to the thickness of at 
 least six inches, a hole for tapping being provided in one of 
 the plates of a proper size to let the metal out when wanted. 
 This ladle may, and is intended to, be lifted about wherever 
 it may suit the mould best. A large trough is now made 
 close up to the tapping-hole of the ladle, about eight feet in 
 length, and three feet deep by four feet broad ; this trough 
 to have a gradual fall of four or five inches from the tapping- 
 hole of the ladle, and the lower end being fitted with a loam- 
 plate having a hole eight inches by six. On the face of this 
 last plate is carefully fitted a shutter-plate, covered with 
 loam and dried, it being necessary that no metal should be 
 able to find its way past the shutter during the time the 
 trough is being filled from the ladle. This trough is often 
 made with sand, but we think a loam-trough is best. A 
 bottom-plate, two side-plates, and an end-piece for the shutter 
 are easily made, and the expense of laying a single brick all 
 over them is very little. This may be kept, or, if preferred, 
 it can easily be taken to pieces until it is again wanted. The 
 tapping-hole of the ladle, five inches by four, is carefully 
 rammed hard with sand and blacking in nearly equal parts, 
 a plate covering the hole, with a bar running across. The 
 blacking makes the sand free and open, so that no time may 
 be lost when the ladle is ready for tapping. On the removal 
 of the bar and plate, the sand is found to leave the hole 
 
 L 
 
U2 
 
 A TREATISE ON 
 
 freely. The ladle and receiver (or trough) must be set 
 sufficiently high above the head of the mould to drain off all 
 the metal that may be in them. Two cupolas supply the 
 metal ; a ladle, of capacity to carry three or four tons, being 
 filled from each cupola alternately, soon brings up the 
 requii^ed amount. As much fii^e ought to be in the standing 
 or large ladle as will allow of twelve inches of red cinders to 
 float on the top of the metal ; and the ladle itseK should be 
 covered over with sheet-iron plates, leaving a space at which 
 the three-ton ladle can be emptied. The trough is covered 
 with sheet-iron plates and sand, in order to kee^D the heat off 
 the workman, who takes his position by the shutter or sluice. 
 All being ready, the ladle is tapped, and the metal runs 
 wildly into the trough, sending up a cloud of dust, blacking, 
 and sand. The man at the shutter must stand firm, keeping 
 his eye on the metal as it surges and heaves higher and 
 higher until it is within an inch- and- a-half from the top of 
 the shutter, which he lifts, and the metal quickly finds its 
 way into the head. He must note how the mould is taking 
 the metal, that all the gates are supplied, and that he is not 
 overflowing the head. In this way not a word need be heard 
 from any one, and the casting is accomplished, as it ought to 
 be, clean, and without noise. 
 
 A large ladle may be built wholly of bricks and loam in a 
 nine-inch wall, swept up with a board like an ordinary loam- 
 mould, strengthening-plates an inch thick being laid on the 
 building at every two courses of bricks, which plates should 
 be seven or eight inches broad. After the ladle is dried and 
 put in position, it requires to be rammed firm with twelve 
 inches of sand round the outside, plates being cast for the 
 purpose of holding the sand and resisting the ramming. 
 
 This ladle can, however, be made without ramming, when 
 proper provision is made for the purpose. This is done by 
 making the building-rings an inch^and-a-half thick instead 
 
IRON FOUNDING. 
 
 143 
 
 of an incli only, allowing three inches of loam on tlie edge of 
 the rings inside, and easting-prods (flat) or dabbers on the 
 outside edge. The dabbers should be strong, say three inches 
 broad, one inch thick, and not more than nine inches long. 
 The plate (or ring) should be cast broad enough to allow the 
 prods to come outside of the brick-work, and the rings to 
 bear upon the dabbers of each other ; the last one on the top 
 must have six snugs, to enable the whole to be bolted firmly 
 down to the bottom plate upon which the ladle is built. The 
 object in having three inches of clearance on the edge of the 
 rings is to keep the latter from expanding, so as to prevent 
 breaking, owing to the great heat of the metal. This plan 
 makes a strong ladle, and is, in our opinion, better than that 
 of ramming the outside with sand. These two kinds of ladles 
 are in use where there is no air furnace. 
 
 AIE-FUENACE. 
 
 The best mode of gathering metal for large castings is that 
 of collecting it in the air-furnace. This might be more appro- 
 priately termed a gathering furnace, as it is only used for 
 storing large quantities of molten metal ; it is, however, 
 generally called an air-furnace, seeing that it provides its 
 own air through having a long chimney. The form of the 
 air-furnace is as nearly as possible that of an ordinary forge 
 furnace. It is usually built to contain sixty tons of melted 
 metal, but when only thirty tons are required, the bottom is 
 raised with rammed sand to suit. The mode of working this 
 furnace is quite different from that of the cupola. The fuel 
 is coal, the most suitable kind being that which produces 
 the greatest flame. 
 
 The air-furnace is usually charged with six tons of pig-iron 
 on the bank, so placed that the flame has free course between 
 the pig bars. Heavy lumps of iron, of thi^ee or four toni^ 
 
lU A TREATISE ON 
 
 eacloLy or even more, may be placed on tlie bank instead of 
 pig ; in this way lumps which, are too large and heavy for 
 the cupola may be disposed of. The furnace is always 
 charged before being lighted. TV hen all the metal on the 
 bank is melted, a circimistance which is noted through a 
 sight-hole on the side, the furnace is ready to receive the 
 metal from the cupola. This is done by having an inlet or 
 oblong hole in the lower end of the furnace near the top, the 
 hole being about six inches by four. A shoot or runner made 
 of sheet-iron plate, lined with dry loam, is made sufficiently 
 long to suit the sweep of the crane which is to hoist the metal 
 from, the cupola. This shoot has a basin at the end opposite 
 to the air-furnace, so that the metal may be freely and quickly 
 emptied into it. It is supported on a raised scaffold, upon 
 which the men stand. 
 
 A three or four-ton ladle is generally used for the pur- 
 pose of conveying metal from the cupola to the air-furnace. 
 Immediately the ladle is emptied a stopper is put before the 
 inlet to prevent cold air passing into the furnace. Whatever 
 length of time the cupola may take to produce the quantity 
 of metal requisite for the casting, no relaxation must take 
 place in keeping the air-furnace well supplied with fuel, so 
 that a strong flame may be kept continually passing over the 
 top of the melted iron until the requisite quantity is gathered. 
 
 The air-furnace has its advantages as well as its draw- 
 backs. The advantages are as follow : — ^The moulder can 
 rest in assurance of having his iron in first-rate condition ; he 
 need not be afraid of his casting being cold-shot in any part 
 as far as good iron is concerned. The circumstances of the 
 metal being first melted in the cupola, and then run into the 
 furnace, are about tantamount to having it recast, as the 
 different brands of pig and scrap-iron become thoroughly 
 blended. Again, the playing of the flame over the surface 
 of the iron is calculated to extract a great proportion of the 
 
IRON FOUNDING. 
 
 U5 
 
 sulphur wliicli permeates all kinds of metal more or less. 
 Last of all, the cast is virtually under the control of one man 
 during the process of filling the mould, the receiver or trougli 
 being provided at the front of the furnace in a manner 
 similar to that at the front of the built ladle. On the other 
 hand, the disadvantages of the air-furnace are its first cost, 
 the extra space required for it to be built on, and the extra 
 expense which is incurred in fuel when i^ is in use. Those 
 are the three primary objections. But in our opinion they 
 are not to be compared with the utility and advantages that 
 an air-furnace possesses in storing a large quantity of metal 
 fit to produce a good, strong, clean, and sound casting. 
 When the weight of any casting, especially cylinders, . is up- 
 wards of twenty tons, the metal ought certainly to be run 
 from an air-furnace. 
 
 OHILLED CASTINGS. 
 
 As hot wrougbt-iron or steel becomes hard wlien immersed 
 suddenly in cold water, so does cast-iron become liard when, 
 being in a liquid state, it is allowed to come into contact with 
 eoid iron. When a eertaia portion of a casting is required to 
 be made hard, the corresponding part of the mould must be 
 always of cold cast-iron, and well coated with black-lead. 
 
 A mould may consist partly of loam or sand and partly of 
 metal. In some foundries moulds of this description are in 
 frequent use. 
 
 Wheels for mining districts receive their bores by having a 
 cast-iron and sometimes a steel core, which is slightly tapered 
 to admit of its being freed from the casting by a stroke of a 
 hammer. The casting is never left to cool entirely before the 
 core is removed. 
 
 Chilled railroad car wheels represent anotlier article in 
 which iron is employed as a part of the mould, being greatly 
 in use for that purpose in the United States of America. 
 
UG 
 
 A TREATISE ON 
 
 The outside of the mould, wliich forms the rim of the cast- 
 ing, is merely a heavy piece of cast-iron, turned or rather 
 bored out in the lathe ; but as such castings are specialities, 
 little need be said about them, as the principle of moulding 
 them is just the same as if there were no chill at all. 
 
 It may suit our purpose better to consider the effect which 
 the chill has upon the casting, and the effect which the metal 
 has upon the chill, if any. When the casting is thick at a 
 part that has to be chilled, the chill-plate has to be pro^Dor- 
 tionately thick, in order to resist the great heat imparted fi^om 
 the metal, else no chilling would take place. As well might 
 the smith try to temper his steel in warm water as the 
 moulder try to chill his casting on a thin chill-plate. Suppose 
 we take a forge-anvil, say a cubic foot in size, and use a chill- 
 plate an inch thick, very little chilling on the face of this 
 block would result ; but suppose the chill-plate to be five 
 inches thick, the casting will then be as hard as steel on 
 the face, the hardness penetrating into the casting three- 
 quarters-of-an-inch. Such is the effect of a heavy chill 
 on heavy metal, decarbonising the metal that lies on the 
 jilate to a certain depth, and causing it to become No. 8, or 
 white iron. 
 
 Has the circumstance of heavy metal having been often 
 used any effect upon the chill ? Our experience teaches 
 that it has an effect, and that not for the better. ^Tien a 
 chill-plate has been used several times with heavy metal, the 
 surface of it becomes as it were dead, and begins to produce 
 a rough and ugly face on the casting, the metal actually 
 refusing to lie quietly upon it, owing to the surface of the 
 chill-plate having become non-porous, giving the face of the 
 casting an appearance as if it had been cast in very wet sand. 
 Thus the chiU-plate imparts virtue at first to the casting, at 
 the expense of its own. To many readers this assertion may 
 appear strange ; but we must bear in mind that it is extra 
 
IRON FOUNDING. 
 
 147 
 
 heavy metal here spoken of, which we know is decidedly 
 different from ordinary chilled castings. Those chills may 
 and do last a considerable time before they are considered 
 useless. 
 
 "When a chill-plate four inches thick is broken up, having 
 been in use for some time with heavy metal, it will be seen 
 to be what the moulders understand as burnt," the face of the 
 chill being burnt in an inch deep, like the top of an old fire- 
 bar that has been long in use, which clearly shews that the 
 chill-plate suffers. 
 
 Tools for planing castings can be cast and chilled at the point 
 to a degree harder than common steel ; but they will not 
 stand to be tempered in cold water like steel, for when tried 
 in this way they immediately fly into many pieces. 
 
 A chill to be used for any purpose may crack on its first 
 use and become useless ; in order to avoid this as far as 
 possible it should be cast of the best hematite iron. In the 
 ease of roller chills, they are, as a further preventive, bound 
 with wrought-iron rings. 
 
 "When a chill-plate forms the bottom of any mould the 
 metal can be admitted on the face of the chill with perfect 
 safety, as it soon becomes covered by the metal before the 
 slightest impression is made upon the chill. The chill ought 
 to be perfectly clean and free from rust, as where there is 
 oxide molten metal refuses to lie at peace. It is also advis- 
 able to make the chill slightly warm previous to casting. 
 
 MALLEABLE CAST-IEON. 
 
 In producing malleable cast-iron castings the principles 
 followed in moulding them are much the same as in ordinary 
 castings. All that tends to make malleable cast-iron is in the 
 quality of the iron which fills the mould, and in the anneal- 
 ing process, the latter part being the most important, and 
 which is patented. 
 
us 
 
 A TREATISE ON 
 
 The manufacture of so-called malleable-iron castings re- 
 quires No. 5 brand (hematite) as metal in which, there is 
 little carbon, and that little in a combined state. It is a white 
 metal, parting easily and equally with its carbon in the 
 annealing operation. It may be melted in the cupola in the 
 same manner as ordinary iron ; but in the case of the best 
 class of malleable cast-iron, it is melted in crucibles, or in a 
 small furnace for the purpose. The shrinkage of this hard 
 iron is greater than in grey iron, being as nearly as possible 
 a quarter-of-an-inch to the foot. Fred. Overman says that 
 the manufacture of malleable iron castings is older than is 
 generally supposed. Although the knowledge of the true 
 principles on which it is based dates from the more recent 
 period of the establishment of chemical science, and though in 
 1722 a Frenchman, whose name was Eaumur, experimented 
 with cast-iron to produce malleable iron, and succeeded, yet 
 the process had been effected twenty years before that time, 
 but in a secret manner. Eaumur found, in his experiments, 
 that oxides of iron and cast-iron, heated together in closed 
 vessels, produced malleable iron. 
 
 Malleable castings are now extensively in use, even up to 
 the weight of three and four tons, such as water-press cylin- 
 ders for callender works, which are subjected to a great pres- 
 sure, up to seven thousand lbs. on the square inch. They 
 used to be cast with ordinary iron, seven inches thick round 
 the barrel ; but they are now mad-e from malleable cast-iron, 
 only three inches thick, and they resist successfully the enor- 
 mous pressure put upon them, which in many instances the 
 seven-inch ones could not stand, they often being rent from 
 top to bottom. Again, the same kind of castings are now 
 frequently used for heavy and important parts connected with 
 large marine engines ; and for tools of all descriptions malle- 
 able cast-iron is now extensively used. The art is to cause 
 this chemical change to take place in the metal after the 
 
IRON FOUNDING. 
 
 149 
 
 castings are made and relieved from the moulding- sand. 
 They are then arranged in boxes of iron made for the purpose, 
 every casting having to be carefully covered up, and resting 
 upon scales of iron from rolling-mills and ground red hema- 
 tite ore, and then run into a furnace prepared for the purpose. 
 
 This furnace is raised and kept to an exceedingly high tem- 
 perature, and according to the thickness of the casting so the 
 time the castings are kept in the furnace. We understand 
 four or five days and nights are required to anneal some 
 heavy castings. With ordinary castings two days and 
 nights are considered sufficient ; but the length of time re- 
 quired to anneal castings wholly depends upon the article to 
 be annealed. 
 
 Small iron castings are freed from the moulding-sand by 
 being put into a close revolving cylinder, and then packed in 
 boxes with the material already mentioned. 
 
 lio thoroughly has malleable cast-iron superseded the real 
 malleable iron, and to such innumerable purposes is it de- 
 voted, that it is very difficult to actually determine, in many 
 instances, what is the real malleable iron and what is malle- 
 able cast-iron. 
 
 CHAPLETS, AND THEIE USE. 
 
 Chaplets are intended to carry up cores to whatever thick- 
 ness the metal is intended to be, which is usually from half- 
 an-inch up to three or four inches ; not only are they 
 intended to carry up the cores, but they are also used for 
 keeping the cores down in their proper places. They are 
 most used in marine-engine castings, either in dry-sand or 
 loam moulds ; and also for such castings as cylinders, con- 
 densers, sole-plates, pistons, covers, &c. 
 
 We cannot state here when and where and of what 
 strength chaplets should be put in a mould, because moulds 
 
150 
 
 A TREATISE ON 
 
 are so varied in form, and so much depends upon circum- 
 stances. Thus, a weak core-iron requires extra support here, 
 or a weak part of the mould needs to be helped with a chaplet 
 there ; in fact, so many exigencies occur which require, in 
 the moulder's judgment, the use of a chaplet, that no rule 
 can be properly laid down for the use of them. This, how- 
 ever, we may safely say, that the fewer chaplets there are in 
 a mould the better the casting, its safety being also considered. 
 
 The evils that are attendant on chaplets are twofold. In 
 some cases they are very apt to encourage a casting to crack, 
 especially when there are many of them spread over the top 
 of a core, say on a large condenser an inch-and-a-quarter 
 thick, or on a flat plain surface in any casting. The chaplet 
 tends to weaken the plate, as the malleable iron is quite 
 foreign to the cast iron. In the second place, should the 
 chaplet have the least impurity on it, such as oxide or rust, 
 this is apt to produce holes in the metal, or a porousness all 
 round the region of the chaplet. The oxygen from the 
 impure chaplet combines with the carbon of the cast-iron and 
 forms carbonic oxide gas, which is prevented from escaping 
 by the pressure of the liquid iron ; it therefore holds its 
 place, and makes clear holes — ^large and small — all round the 
 chaplet. These holes or porousness may not be seen on the 
 face of the casting, either inside or out ; stiU in many cases 
 they exist, as can plainly be seen when old castings, and 
 sometimes new ones, that have had chaplets in them are 
 broken up. It will be noticed, then, how apt steam — especi- 
 ally high-pressure steam — is to cause mischief, when it 
 happens to come in contact with a part where a chaplet is 
 bedded in porous cast-iron. To obviate or reduce this car- 
 bonic oxide the moulder has tried many things with his 
 chaplets, such as rubbing them slightly with oil, red lead and 
 turpentine, or coal-tar, dipping them in a mixture of lead and 
 tin, making them red in a fire, and so on. The mixture of 
 
IRON FOUNDING. 
 
 151 
 
 tin and lead is very good, but the plan of making eliaplets 
 clean with, fire is better. Tinned chaplets are greatly used, 
 as they do not rust easily, and time and trouble are saved by 
 using them. This latter is the sole reason why tinned chap- 
 lets are sought after. 
 
 Chaplets are a source of weakness to any casting, especially 
 when there are many, and they happen on the part of a casting 
 which is cast up, /. e., the moulder's top. When they are 
 placed in the bottom of the mould, or even when used for 
 the purpose of staying, sometimes called jamming,'' the 
 cores between themselves, or between the outside of the 
 mould and the core adjoining the outside, they are much less 
 injurious. The pressure of the metal in this instance is. 
 greater and the metal cleaner, which circumstances go far to 
 counteract the ordinarily evil influence of chaplets. No 
 moulder in loam or dry-sand, ancl in many instances in green 
 sand, can dispense with them ; but they are often put to an 
 indiscriminate and needless use by even good moulders, thus 
 causing not only harm to the castings, but unnecessary 
 expense to the master. Nothing pains a proper moulder's 
 eye so much as when he looks into a mould that is being 
 closed or put together and sees chaplets here and there where 
 there is no use for them, looking as if they had been shaken 
 out of a riddle. Some moulders can hide double the quantity 
 that others do in making a casting from the same pattern. 
 A\Tiy is this ? Simply because a first-class moulder thoroughly 
 understands what part of his mould really requires chaplets. 
 
 The common chaplet for loam and dry-sand is merely a 
 piece of stout hoop-iron nine inches long, with three flat- 
 headed nails rivetted into it, the nail-stalk having a good 
 shoulder for the hoop-iron to rest upon. The green-sand 
 chaplet is simply a piece of rod-iron, from t^eths of an inch 
 diameter or square up to three-quarters -of -an-inch, which is 
 termed the stalk, and made to suit the job, a piece of hoop- 
 
152 
 
 A TREATISE ON 
 
 iron or stout plate (as the case may be) being rivetted at the 
 end of the stalk of from an ineb-and-a-lialf up to four or five 
 inches in length, according to circumstances. 
 
 Some castings are bad, and some faulty, owing to the core 
 or cores rising from their proper places when the pressure of 
 metal comes upon them. This may not be from the want of 
 ohaplets, but because the chaplet has sunk into the core, or 
 the nails have been pressed into the top part. The metal in 
 either case will be thin above the core. 
 
 The foregoing description of chaplets may serve for a mould 
 in which there is no great lift upon the cores ; when, how- 
 over, the pressure is very great, they are wholly inadequate, 
 and something else must then be done. When the moulder 
 considers that the ordinary or common chaplet will not hold 
 down his core, unless indeed he uses a great many of them, 
 which, as we have abeady shewn, is distinctly bad, he should, 
 in making his core, raise up iron props at proper intervals 
 from the main core-iron to within an inch from being flush 
 with the core. Holes must be made in the top part to admit a 
 piece of round or scj^uare iron of a proper strength, say from 
 half-an-inch up to one inch, to rest upon the iron props in 
 the core. These irons, or chaplets, as they are sometimes 
 called, are then bound fast to the top part, or the bar running 
 over the top part, which prevents the care from moving. The 
 core of a large condenser, or other heavy casting, may be 
 held in its place with six of these chaplets, making little or 
 no mark in the casting, whereas it woidd take thirty-six 
 ordinary tinned chaplets to do the same work, indeed we 
 question if it could be done with even that number. 
 
 Large columns, cast horizontally in sand, should never be 
 cast without chaplets of this kind, as the core is bound to be 
 in the centre of the casting. The pieces of iron leading to 
 the iron props from the core-bar, or core iron, can be covered 
 with a coating of loam and blackened ; they can then be 
 
IRON FOUNDING. 153 
 
 taken out of the casting, leaving a clean hole like a core-hole>^-^ ^ 
 which can be easily tapped up, when the thickness of the 
 metal can at once be noted. Where numbers of columns are 
 made and contracted for this is what should be done. The 
 inspector of the casting would then have no trouble in know- 
 ing at once the thickness of the column. The hole would 
 only be an inch-and-a-quarter at the most, not in the slightest 
 degree weakening the casting. The metal runs kindly and 
 smoothly round this loamed chaplet, no honey-combing can 
 take place here, and in our opinion it is the very best of 
 chaplets. 
 
 The reason for keeping the iron props an inch or so from 
 the surface of a large core is to allow the casting to contract. 
 The props on a large pipe or column core-bar or spindle 
 may be kept flush with the core, as the casting has ample 
 liberty to contract from the space in the under-side of the 
 core-bar or spindle. To do this requires extra time and 
 labour on the moulder's part ; and we apprehend that where 
 there is keen competition among moulders for work in which 
 it should be done, and piece-work prevails, this requirement 
 of extra labour is the main reason why it is not always done, 
 the common stalk chaplet being resorted to in the sand 
 column, and a greater number of three-studded chaplets in 
 the dry-sand and loam castings. 
 
 Cast-iron chaplets can be used to great advantage in stay- 
 ing or jamming cores, care being taken that they are not in 
 the way of any running gates, as in that case they would 
 quickly melt ; neither should wrought-iron ones be in the 
 way of gates, as they also would quickly disappear. 
 
 A three or four-inch round core the exact thickness of the 
 metal, made strong with iron, and resting upon a strong part 
 of a main core, makes a capital chaplet, when it is placed 
 upon a part of the casting to which access can be had to tap 
 them up. Engineers prefer to tap these holes rather than 
 
15-1 
 
 A TREATISE ON 
 
 see a host of cliaplet nail-lieads shining through the skin of 
 the casting. 
 
 Twenty years since chaplets were commonly made with 
 double-plated instead of flat-headed nails, that is, with three 
 studs rivetted between two stout hoop-iron plates, for the sole 
 purpose of being more able to resist the pressure of the metal, 
 by affording a larger surface to prevent them from sinking 
 into either the mould or the core. Nothing could be seen 
 more ugly at that time on a casting than these hoop-iron 
 plates shining and sticking in numerous instances all over it ; 
 but, like the progress of other things, chaplet-making and 
 the proper use of chaplets have wonderfully improvedi 
 
 SHOP MANAGEMENT. 
 
 The person who has control over a casting shop ought to 
 possess two qualifications ; first, he should be able to manage 
 or control himself ; second, he ought to be thoroughly con- 
 versant with the work, in all its branches, that has to be 
 •carried on under his direction. A man who is continually 
 losing control over his temper soon ceases to be respected by 
 his subordinates, and in proportion as he does this he loses 
 control over them. A man will at times lose his temper, but 
 it ought to be as seldom as possible, and then only when he 
 has a just reason. He should be a competent workman in 
 every detail — able to know when a man is working to some 
 intent, or frittering away his time — able to discern what a 
 man really can do, and place him at the kind of work that he 
 is suited for — able to discern the character of a man, and to 
 know when he is working cheerfully or the reverse — able to 
 read his men and shop like a book, from the youngest appren- 
 tice to the oldest journeyman, and to tolerate no shouting or 
 undue noise. Familiarity breeds contempt ; the foreman's 
 distance from the men ought to be such as to promote respect, 
 
lEON FOUNDING. 
 
 155 
 
 and yet not so niucb. as to preclude them from speaking to 
 Mm. He ought always to be ready to assist and encourage 
 anyone who has got into difficulties with his work, provided 
 that such difficulties have arisen from errors of judgment. 
 He should evince no partiality, and shew no favour, treating 
 every workman alike. He ought to have a mind of his own 
 on the work, and yet not be above taking a hint from a 
 labourer. In this respect he should fear neither master nor 
 men, as they are both quick at detecting anything of that 
 kind, and neither party is slow to take advantage of it. 
 
 A foundry when busy seems to the visitor a place of con- 
 fusion, and the thought strikes him — Could it not be kept in 
 better order than this ? More especially is this apt to be the 
 case on the morning after a cast. In the sand department 
 heaps of dried sand, boxes empty and half-empty, scraps, 
 gates, runners, and castings may all be lying in juxta- 
 position to each other. In the loam department are to be 
 seen great holes in the floor, rough-looking buildings of 
 bricks in these holes or pits, a lot of bricks on the floor, 
 boxes of dirty-looking loam, bruised buckets containing dirty 
 water, blacking, and clay-water, ashes, bricks, core-irons, 
 straw ropes and loose straw, sawdust, chains, beams, ropes, 
 and many other things, all of which give the foundry an air 
 of confusion. On this account the visitor should come in the 
 middle of the day, when all things have got put into order. 
 All the things, however, that we have mentioned are of use 
 to the moulder, who is continually using them. Some foun- 
 dries are much worse than others in this respect. The con- 
 struction of the foundry has a deal to do with it, in not 
 allowing easy and free access to a yard; bad management 
 has also something to do with it, the foreman, for the sake of 
 economy, doing with less labourers than he ought to have for 
 the work in hand ; but this is not really economy ; the fore- 
 man may be employing fewer labourers, but on this account 
 
150 
 
 A TEE A USE ON 
 
 he is not getting sufficient work from the moulders, so tliat 
 wliere lie saves on the one hand he loses on the other. After 
 all that has been said, however, it is the duty of a moulder to 
 discern when a foundry is kept in proper order. 
 
 THE rOEMATION OF A FOUNDEY. 
 
 No one can properly say much on this subject unless he 
 first knows what class of work it is proposed to carry on. 
 Foundries where only one class of work is engaged in require 
 to be very different in design from those of a totally di fit erent 
 class. A foundry where nothing but grate-metal and hol].ow 
 work is carried on will be very different from another in 
 which only railway chairs are cast, and that again different 
 from one which produces nothing but pipes made by machi- 
 nery. Their requirements are so varied, and the necessities 
 of each so peculiar to itself, that, as we have already observed, 
 no one can properly lay down a hard-and-fast Kne as to what 
 is the best form of a building for a foundry without first 
 knowing to what purpose it is to be devoted. But suppose 
 we take a general foundry, otherwise called a jobbing 
 foundry, where all three branches are to be carried on, from 
 the lightest to the heaviest of castings. 
 
 The best plan for such a shop is of an L shape, one part 
 being devoted to green and dry-sand, the other to loam. The 
 foundry-building in this case embraces the yard. The roof 
 should be high, capable of giving plenty of light, and well 
 qualified to keep out wet. The smoke that arises from the 
 pits requires that the roof should be extra high. The cupolas 
 and air-furnace (and no foundry where heavy work is done 
 should be without the latter), as well as the pits and stoves, 
 can be well placed in a foundry of this shape. It is, as it 
 were, two shops having easy access to the same yard ; and 
 yard-room, with easy facilities for going to and from them. 
 
IRON FOUNDING. 
 
 157 
 
 is a most important consideration to the moulder. 
 
 Steam travelling- cranes are better than jibs, provided that 
 light jib-cranes are distributed at proper intervals throughout 
 the shop, as a twenty or thirty-ton over-head steam- crane 
 cannot work the light parts of a mould in closing or parting 
 with the requisite steadiness. 
 
 Sometimes the position of the site chosen, or other circum- 
 stances over which there is no (control, may influence the plan 
 of a foundiy ; but of whatever plan it may be, a wide and 
 ready outlet to a space of ground for boxes and plates is most 
 essential ; the foundr^^ should be used only for moulding. 
 
 Many foundries clean their large castings in the yard with- 
 out any covering, but this is not good either for the men or 
 the castings ; men cannot work so well when uncomfortable 
 with wet, and the castings are not so quickly or so well 
 cleaned when they get wet ; provision should therefore 
 always be made at the extreme end of the foundry foi? clean- 
 ing both heavy and light castings. 
 
 WEIGHTS OF CASTINGS. 
 
 It is very important that a moulder should know what 
 quantity of metal is requisite to fill his mould. We cannot 
 think of a more galling and annoying matter than to have a 
 w^ell-made mould cast short of metal, and more especially 
 is this felt when probably two weeks have been spent in 
 making it ready for casting. 
 
 When we consider the loss to the employer in waste of 
 material, wages, wear and tear of plant, and sometimes the 
 casting is wanted urgently, it becomes a serious matter when 
 too little metal has been provided, not only with a large 
 mould, but equally so with ordinary or small castings. 
 
 Twenty years ago, when a twenty or thirty-ton casting' vras 
 made, it was usual to have about ten tons more of metal than 
 
 M 
 
us 
 
 A TREATISE ON 
 
 was required, and yet it was not uncommon for tlie cast- 
 ing to be short. But in these days of keen competition, 
 when economy is the watchword, the moulder can neither 
 have the one nor the other ; the expense in melting more 
 metal than is absolutely required for the mould and heads, 
 and the breaking up of that metal, will not now be tolerated^ 
 much less will they be allowed to be cast short. It therefore 
 requires the moulder to measure his pattern carefully, and 
 also the mould, totalling the whole up in feet or inches. We 
 will now give a few easy rules, which we are sure every 
 moulder will be able to understand, and to put in practice : — 
 
 Flat Irons'. 
 
 The weight of a superficial foot of cast iron an inch thick 
 is 37*84 lbs., but there is no real necessity for a moulder using 
 the above. The weight of a malleable iron plate the same 
 size is 40 lbs. These latter figures will suit the moulder 
 better, as the 2 J lbs. extra make up for any irregularity that 
 occurs in moulds ; and it is an easy sum to multiply any 
 number of feet by ; for every eighth part more add 5, and 
 for every eighth less than an inch deduct 5. 
 
 For example, a plate 6 feet square and 1 inch thick : — 
 
 6X6=:36 
 40 
 
 1440 lbs. 
 
 The actual weight in cast iron is 1363*392 
 
 77 lbs. 6 oz. difference. 
 
 Eule 2. 
 
 Multiply breadth by thickness in inches, and by 10 as a 
 constant, divide by 3 as a constant, and by the length in feet. 
 
Wrought-iron rule, 
 and may be used 
 for cast iron. 
 
 Example : — Breadths 72 inches 
 
 3)720 
 
 240 
 
 10 
 
 6 Length in feet 
 
 1440 lbs. 
 
 Eule 3. 
 
 It is easily remembered, and quite aa much to the moulder^s 
 purpose, to consider ever}^ 3 square feet 1 inch thick = 1 cwt. 
 
 EouxD Plates. 
 
 Tu find the number of feet contained in a round -gtY^te of 
 any given size : — 
 
 Square the diameter, and multiply the product by '7854. 
 Example. -7854 
 
 When the mould is of a cylindrical form, multipty the 
 diameter by 3-141G and by its length; the number of feet 
 will then be had, cutting off the four right hand decimal 
 figures, or, to be quicker and quite near enough, multipl}^ the 
 diameter by 3, adding a foot to every 22. 
 
 Example. Diameter 11 feet. Diameter 11 feet 
 
 A plate 3 feet diameter =: 9 
 
 7-0686 
 
 Very little more than 7 feet is in this plate. 
 
 Cylixdrical Bodies. 
 
 3 
 
 3-1416 
 11 
 
 34-5576 
 
 Answer 34J feet 
 
 Answer 34 feet 6 J inches. 
 
160 
 
 Spherical or Kouxd Balls. 
 
 Cube the half of any given diameter in inches and divide 
 
 by 10 as a Constant. 
 
 Example. Diameter 8 inches, the half 4, cubed 64. 
 
 Divide by a constant number 10)64 ) » 
 
 6-4 ] 
 
 Answer, exact weight in lbs. 70*4 cast iron. 
 
 Round Bars, in Cast Iron. 
 Multiply the square of the diameter in inches by the length 
 in feet, and by 2-5 : — the product will be the approximate 
 weight in lbs. 
 
 Example. A round bar of iron diameter 3 inches, length 
 2 feet. 
 
 3x3 = 9x2ziil8x2-5z=45 0 lbs. 
 
 Pipes, One Lineal Foot. 
 Subtract the scj[uare of the inside diameter from the square 
 of the outside diameter, then multiply the difference by 2*45, 
 the answer will be in lbs. 
 
 Example. A pipe o inches outside, and 4 inches inside, 
 1 foot in length. 
 
 Outside 5X5=1=25 2*45 
 Inside 4x4-.= 16 9 
 
 9 22-05 lbs. 
 
 jl^he specific weight of cast iron is 16 times heavier than 
 common soft wood. 
 
 The foregoing simple rules all moulders may easily 
 remember ; they have only to be careful to find the number 
 of feet in the mould, and the rest is easy. 
 
 He must consider how much metal should be provided so 
 as to fill the head or gutter, so that the casting may have 
 pressm-e ; then, of course he must know what the ladle or 
 ladles will carry when they jare clean. When the ladle is not 
 
101 
 
 quite clean, or tlie metal seems to be dull, an extra quantity 
 should l3e provided, as a portion of the metal clings to the 
 ladle in either case. In all very large and important 
 castings it is better to have two tons more than may be 
 actually required for the mould and heads. Provision can be 
 made to use the surplus either for an open sand plate on the 
 bed or a small mould provided for the purpose. 
 
 Moulders are accustomed to the use of ropes and chains, 
 and we have thought fit to give the following simple rules, 
 so that they may have some idea of their relative streno;ths, 
 when the chain or ropes are known, or supposed to be, in 
 good condition : — 
 
 Ropes. 
 
 Mr. Mogg says, to ascertain the strength of hempen ropes, 
 square tlie circimiference of the rope in inches, divide by 5, 
 and the answer is in tojis or parts. 
 
 Example. Circumference 3X3=:9~5 = 1'8 or 1 ton 16cwt. 
 Breaking strain, 2 tons 5 cwt. Admiralty test. 
 
 Common Rope. 
 
 Mr. Molesworth says, square the circumference in inches 
 and multiply by •2. Answer is breaking strain. 
 
 Example. Circumference 3x3=9X'2 = l'8orl ton IG cwt. 
 
 Breaking strain rule for hempen ropes : — Multiply the 
 square of the circumference by '28. 
 
 We adopt the following rule of our own for safe working: — 
 
 Hempen rope : square the circumference in inclies, and 
 multiply by 4 ; the answer is in cwts. 
 
 For common rope multiply by 3, and the answer will be 
 in cwts. 
 
 Chains, Shout Link. 
 Mr. Hoare says, for chains, safe working, square the 
 diameter in eighths and divide by 8. 
 
 Example, f =:],^=36-i-8z=:4*o Answer, 4 tons 10 cwt. 
 
Ml A TREATISE OX 
 
 Admiralty proof for this cliain, 6 tons, breaking strain, 
 10 tons 4 ewt. Many parties think 8 too high as a divisor, 
 and adopt 6. We think 8 is safer for sling chains that are in 
 constant nse. 
 
 XOTE. 
 
 To lind the breaking strain — Square the link in eighths, 
 and multiply by -356. 
 
 To find the proof strain in tons — Multiply the square of the 
 link in eighths by '188. 
 
 Chains and ropes become defective through constant use ; 
 the defects in ropes can be easily seen, but not so in chains. 
 It is Trell kno^m that a chain may safely carry thirty ,tons 
 one day, and the day following break with twelve tons, 
 although the former may have been little more than the safe 
 working strain, the reason being, that owing to constant 
 Tattling, severe shaking, and violent jerks, the iron in the 
 link has slightly changed its character ; from being fibrous it 
 has become short in the grain, and when broken, the fracture 
 presents a cast-iron appearance, and is apt to cause an im- 
 pression that the iron composing the chain has been made 
 from bad material. This we believe to be in many instances 
 an error, because when the short-grained broken link is taken 
 to the fire, brought t3 a bright red heat, and allowed to cool 
 ■sloivhj, the link on being again broken will shew quite a 
 fibrousness in the fracture. This, in our opinion, clearly 
 demonstrates that all sling and crane chains ought to be 
 periodicially made to a bright red heat, but unless provision is 
 made for their slow coolino- the heating" will do no material 
 good. 
 
 In the chain that carried the tliirty tons weight one of the 
 links may have been on the eve of parting, yet not be percep- 
 tible to the eye, and when it had the twelve tons to carry, 
 a slight jerk on going round the barrel of the crane would be 
 sufficient to break it. The strength of a chain, however, 
 
IRON FOUNDINO. 
 
 ill a great measure depends upon its use and abuse, irrespec- 
 tive of any liard and fast rule that may be laid down. 
 
 GENEEAL EEMAEKS. 
 
 There is a peculiarity about moulding upon which too- 
 much stress cannot be laid, namely, that a piece of work 
 can onlf/ he done once, and if it is imperfect in any essential 
 particular it is spoiled, and cannot be used for any other pur- 
 pose, so that it must be broken up for scrap, and the work 
 commenced de Jiovo. A commercial man may correct his cor- 
 respondence — the designer may modify his plans during 
 the progress of construction— the joiner or pattern-maker 
 can replace a spoiled piece of wood — the smith can alter 
 a forging, or use up the iron for another purpose — the 
 boiler-maker can re-caulk the rivets, the landings of his 
 boiler, and so on ; but in moulding, the neglect of some 
 trifling thing may damage the whole casting, and it must 
 be condemned. We venture to point out Avitli pardonable 
 pride, considering the slightness of the causes of bad castings, 
 how very few are spoiled. 
 
 Engineers do not hold moulders in the highest esteem, but 
 we think the reason must be their want of knowledge of 
 the difficulties of the moulder's art, and the fuU importance 
 of his work, for it must be borne in mind that by far the 
 greatest weight of the metals used in the construction of 
 machinery is cast-iron. We also take this opportunity of 
 pointing out that incompetent persons, as engineers, are 
 sometimes appointed to examine castings, with occasionally 
 the power of jcondemning them. A lad beginning his ap2)ren- 
 ticeship goes to be an engineer ; he spends a few months in all 
 the different shops, except (be it noted) the foundry, and 
 finishes off in the drawing office. What pretension such a 
 youth can have to the knowledge to examine castings and 
 converse about various metals and the mixing of them is 
 
164 
 
 A TREATISE OS IRON FOUNDING. 
 
 not quite apparent ; 3'et positively it is to such persons, in 
 many eases, tliat the overlooking and inspection of castings is 
 entrusted ; and by this means the moulder suffers. It is 
 sometimes laid to the charge of moulders that they hide the 
 faults of castings. Now, although we strongly condemn this 
 practice, under all circumstances, we still admit a slight 
 excuse for the moidder doing so when he knows that they 
 are to be overlooked by an incompetent person, who may 
 make a trouble about a mark on the surface from ignorance 
 of its real nature and cause, but which affects the casting only 
 in appearance. 
 
 This treatise has been written for both engineers and 
 moulders, and although to the latter much of it must be quite 
 familiar, still it is to be hoped that in many cases we have suc- 
 ceeded in drawing their attention more forcibly than it would 
 otherwise have been to many imjiortant points of the subject. 
 
 It i^ emphatically claimed for the matter of this book, 
 except where quotations from the works mentioned in the 
 preface have been made, that it is in a great measure original, 
 as no book on the subject hitherto published has treated 
 of the actual practice of moulding. It is also a record 
 of the extensive experience of the author, who has been 
 actively engaged in the practice of moulding in England, 
 Scotland, Ireland, the "West Indies, and America. 
 
 In conclusion, we would address apprentice moulders — by 
 whom we hope this book will be much read — in the follovring 
 words of advice — Strive to be master of your trade and to 
 excel in it ; wish rather for that than a big pay, as the pay is 
 bound to follow ; be alwa^'s ready to give attention to your 
 foreman's advice, and never think any work beneath you, as 
 in such a trade as moulding something can be learned in work 
 however mean.'' 
 
 FINIS. 
 
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 Cases of Mathematical Instruments 2s. Gd., 3s. Gd., 7s., 10s.. 12s.. 17s. 6d 
 
 18s., 30s. ■42s. to C3s 
 
 Drawing and Indicator Scales . . . . . . . 4s 
 
 Burbridge's Indicator Scales per Packet . . . . . . Is 
 
 Gunter's Scales . . . . . . . . . . . . 2s. Gd 
 
 Hawthora's Slide Rule . . . . . . . . . . 10s. 6d 
 
 Protractors . . . . , . . . Wood Is., Ivory 4s. Gd 
 
 Sectors . . . . . . . . . . . . . . Od 
 
 T Squares, 12in. to 3Gin. . . . . . . . . Is. to 3s 
 
 Set Squares. 45° and 60^ . . . . . . . . 2d. to 2s 
 
 Parallel Rules .. .. .. . . from 9d. to lis 
 
 Thermometers .. .. .. .. is. Gd., 2s. 6d 
 
 Bow Pens and Pencils . . . . . . . . 2s 
 
 Drawing Boards . . . . Is. 9d., 2s., 2s. 3d., 3s. Gd., 3s. 9d, & 4s. 6d 
 
 Drawing Books . . . . . . . . . . from 3d. to 2s 
 
 Drawing Paper . . . . . . from Id. to 3s. Gd. per sheet 
 
 Indicator Paj)er, per Packet. . .. .. .. .. 6d 
 
Date Due 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 I 
 
JUST PUBLISHED, PRICE 10/- BY POST, 10/6 
 
 M^79 ' 
 
 s 
 
 ERS' 
 
 AuTiio: 
 
 N 
 
 ?HISTLE," &C. 
 
 ILLUSTRATED WITH DIAGRAMS 
 
 SUNDEELAND 
 
 PRINTED AND PUBLISHED BY AND FOR 
 
 THOMAS REED & CO. 
 
 LONDON: Simpkin, Marshall, k co. ; Hamilton, Adams, & Co. 
 
 R. H. Laurie ; and Imray &^Son. 
 
 GETTY CENTER LIBRARY 
 
 3 3125 00002 1283 
 
I