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with oil, and melted together. Used in the commoner kinds of tea-boards, &c. Silver Bronze.—Bismuth and tin, of each 2 lbs.; melt together and add 1 lb. of quicksilver. Pound all together into a powder. This soft fusible amalgam is used as an imitation of silver bronze for plaster figures and other common purposes, in the same way as the aurum musivum is for gold-coloured articles. It may be used as spangles in sealing-wax; it must then be mixed when the resinous part of the wax is getting cold. Gold Powder for Bronzing.— Leaf gold is ground with virgin honey on a stone, until the leaves are broken up and minutely divided. The mixture is removed from the stone by a spatula, and stirred up in a basin of water, whereby the honey is melted and the gold set free; the basin is then left undisturbed until the gold subsides; the water is poured off, and fresh quantities added until the honey is entirely washed away; after which the gold is collected on filtering paper, and dried for use. Gold Size is prepared from 3 lb. of linseed oil with 2 oz. of gum animi; the latter is reduced to powder and gradually added to the oil while being heated in a flask, stirring it after every addition until the whole is dissolved; the mixture is boiled until a small quantity, when taken out, is somewhat thicker than tar, and the whole is strained through a coarse cloth. When used, it must be ground with as much vermilion as will render it opaque, and at the same time be diluted with oil of turpentine, so as to make it work freely with the pencil. Bronzing Plaster. — Lay the figure over with isinglass size, until it holds out, or without any part of its surface becoming dry; then, with a brush, such as is termed by painters a sash tool, go over the whole, taking care to remove, while it is yet soft, any of the size that may lodge on the delicate parts of the figure. When it is dry take a little very thin oil gold size, and with as much as just damps the brush,
go over the figure with it, allowing no more to remain than causes it to shine. Set it aside in a dry place free from smoke, and in forty-eight hours the figure is prepared to receive the bronze. After having touched over the whole figure with the bronze powder, let it stand another day, and then with a soft dry brush rub off all the loose powder, particularly from the points, or more prominent parts of the figure. Bronzing Wood.—The wood is first covered with a uniform coating of glue, or of drying oil, and when nearly dry the bronze powder, contained in a small bag, is dusted over it. The surface of the objects is afterwards rubbed with a piece of moist rag. Or the bronze powder may be previously mixed with the drying oil, and applied with a brush. Bronzing Paper.—Gum is substituted for drying oil in bronzing paper When dry, the paper is submitted to the action of the burnisher, which imparts great brilliancy to it. Bronzing small Brass Articles.—1 part oxide of iron, 1 part white arsenic, 12 parts hydrochloric acid. Clean the brass well to get rid of lacquer or grease, and apply with a brush until the desired colour is obtained. Stop the process by oiling well, when it may be varnished or clear lacquered. Bronzing Gas Fittings.-Boll the work in strong ley, and scour it free from all grease or old lacquer; pickle it in diluted nitric acid till it is quite clean (not bright), then dip in strong acid, and rinse through four or five waters; repeat the dip, if necessary, till it is bright; next bind it very loose with some thin iron wire, and lay it in the strongest of the waters you have used for rinsing. This will deposit a coat of copper all over it if the water or pickle be not too strong; if such is the case the copper will only be deposited just round where the wire touches. When the copper is of sufficient thickness wash it again through the waters, and dry it with a brush in some hot saw-dust; box-dust is best, but if this is not at hand, oak, ash, or beech will do. It is now ready for bronzing. The bronze is a mixture of black-lead and red bronze, varied according to shade required, mixed with boiling water. The work is to be painted over with this and dried, then brushed until it polishes. If there are any black spots or rings on the work, another coat of the bronze will remove them. Lacquer the work with pale lacquer, or but very slightly coloured, for if it is too deep it will soon chip off. Another method is to mix vinegar or dilute sulphuric acid (1 acid 12 water) with powdered black-lead in a saucer or open vessel; apply this to the brass with a soft plate brush by gentle brushing. This will soon assume a polish, and is fit for lacquering. The brass must be made slightly warmer than for lacquering only. A little practice will enable the operator to bronze and lacquer with once heating. The colour, black or green, varies with the thickness of black-lead. Green Bronze.—Dissolve 2 oz. of nitrate of iron, and 2 oz. of hyposulphite of soda in 1 pint of water. Immerse the articles in the bronze till of the required tint, as almost any shade from brown to red can be obtained; then well wash with water, dry, and brush. One part of perchloride of iron and two parts of water mixed together, and the brass immersed in the liquid, gives a pale or deep olive green, according to the time of immersion. If nitric acid is saturated with copper, and the brass dipped in the liquid, and then heated, it assumes a dark green. If well brushed, it may be lacquered with pale gold lacquer, or else polished with oil. Black Brasswork for Instruments. – Take lampblack, about a thimbleful, and put it on a flat stone or smooth slate; add four or five spots of gold size, and well mix with a palette knife, make the whole about as thick as putty; well mix. The less gold size there is the better, so that the lampblack just sticks together; if too much gold size be added, the effect will be a
bright black and not a dead black. Now
add turpentine, about twice its own volume, to the whole, mix with a camel-hair brush, and apply to the brasswork. Black Bronze for Brass.-Dip the article bright in aquaforts; rinse the acid off with clean water, and place it in the following mixture until it turns black:-Hydrochloric acid, 12 lbs.; sulphate of iron, 1 lb.; and pure white arsenic, 1 lb. It is then taken out, rinsed in clean water, dried in saw-dust, polished with black-lead, and then lacquered with green lacquer. Bronzing Iron.—To one pint of methylated finish add 4 oz. of gum shellac and 3 oz. gum benzoin; put the bottle in a warm place, shaking it occasionally. When the gum is dissolved let it stand in a cool place two or three days to settle, then gently pour off the clear into another bottle, cork it well, and keep it for finest work. The sediment left in the first bottle, by adding a sufficient quantity of spirit to make it workable, will do for the first coat or coarser work when strained through a fine cloth. Next get 3 lb. of finely-ground bronze green, the shade may be varied by using a little lampblack, red ochre, or yellow ochre; let the iron be clean and smooth, then take as much varnish as may be required, and add to the green colour in sufficient quantity; slightly warm the article to be bronzed, and with a soft brush lay a thin coat on it. When that is dry, if necessary lay another coa, on, and repeat until well covered. Take a small quantity of the varnish and touch the prominent parts with it; before it is dry, with a dry pencil lay on a small quantity of gold powder. Warnish over all. Bronzing Copper Utensils.If the article is not new take it to pieces, wiping off all the solder with a wisp of tow, and taking care not to let any of the metal in the fire; then twist a little tow on the end of a stick, and pickle with spirits of salts all those parts that are tinned, pickling the outside as well as the in, rinse in water, and scour outside with wisp of tow and sand, fine coke-dust is best for the remove the sal-ammoniac from the surface, placed immediately on the former and lined at the same heating. Blanched Copper.—Fuse 8 oz. of copper and 3 oz. of neutral arsenical salt, with a flux made of calcined borax, charcoal dust, and powdered glass. Yellow Brass.-30 parts of zinc 2nd 70 of copper in small pieces. YELLow BRASS, for Turning.— (Common article.)—Copper, 20 lbs.; zinc, 10 lbs.; lead from 1 to 5 oz. Put in the lead last before pouring off. Red Brass, for Turning.—Copper, 24 lbs.; zinc, 5 lbs.; lead, 8 oz. Put in the lead last before pouring off. RED BRASS, free, for Turning.— Copper, 160 lbs.; zinc, 50 lbs.; lead, 10 lbs.; antimony, 44 oz. Another Brass, for Turning.— Copper, 32 lbs. ; zinc, 10 lbs. ; lead, 1 lb. Best Red Brass, for fine Castings.-Copper, 24 lbs.; zinc, 5 lbs.; bismuth, 1 oz. Put in the bismuth last before pouring off. Rolled Brass. – 32 copper, 10 zinc, 1.5 tin. Common Brass, for Castings.-20 copper, 1.25 zinc, 2.5 tin. Hard Brass, for Casting.—25 parts copper, 2 zinc, 4.5 tin. Brass Melting.—The best plan of smelting brass is to melt the copper in a black-lead crucible first, dry and cool the zinc as much as possible and immerse the whole of the zinc into the copper when the latter is not hotter than barely to continue fluid. Drop a piece of borax the size of a walnut into the pot. When the surface of the hot metal is covered by fine charcoal, or borax, which is prevented by renewal from burning, the smallest loss of zinc is sustained. The melting together of tin and copper is less difficult than that of zinc and copper, because tin is not so liable to evaporate as zinc, and little metal is lost. The appearance of the alloy may be improved by covering the melted metal with about one per cent. of dried potash; or, better still, a mixture of potash and soda. This flux has a re
markable influence on the colour, and particularly on the tenacity of the alloy. The former becomes more red, and the latter stronger. The scum forming on the surface by this addition ought to be removed before the metal is cast. Tin and copper are liable to separation in cooling; this can be prevented, at least partly, by turning the mould containing the fluid metal, and keeping it in motion until it is chilled. Copper and lead unite only to a certain extent: 3 lead and 8 copper is ordinary pot metal. All the lead may be retained in this alloy, provided the
object to be cast is not too thick.
When the cast is heavy, or much lead is used, it is pressed out by the copper in cooling. 1 lead, 2 copper, separates lead in cooling—it oozes out from the pores of the metal : 8 copper and 1 lead is ductile, more lead renders copper brittle. Between 8 to 1 and 2 to 1 is the limit of copper and lead alloys. All of these alloys are brittle when hot or merely warm. Equal parts of copper and silver and 2 per cent. of arsenic form an alloy similar to silver, a little harder, however, but of almost equal tenacity and malleability. Antimony imparts a peculiar beautiful red colour to copper, varying from rose-red in a little copper and much antimony, to crimson or violet when equal parts of both metals are melted together. Hardening for Britannia.(To be mixed separately from the other ingredients.)—Copper, 2 lbs.; tin, 1 lb. Good Britannia Metal.—Tin, 150 lbs.; copper, 3 lbs.; antimony, 10 lbs. Britannia Metal, 2nd quality.— Tin, 140 lbs.; copper, 3 lbs. ; antimony, 9 lbs. BRITANNIA METAL, for Casting.— Tin, 210 lbs. ; copper, 4 lbs. ; antimony, 12 lbs. BRITANNIA METAL, for Spinning.— Tin, 100 lbs. ; Britannia hardening, 4 lbs. ; antimony, 4 lbs. BRITANNIA METAL, for Registers.Tin, 100 lbs.; hardening, 8 lbs.; antimony, 8 lbs.
Best Britannia, for Spouts.—Tin, 140 lbs.; copper, 3 lbs.; antimony,
Best Britannia, for Spoons.—Tin, 100 lbs.; hardening, 5 lbs.; antimony, 10 lbs.
Best Britannia, for Handles.— Tin, 140 lbs.; copper, 2 lbs.; antimony, 5 lbs.
Best Britannia, for Lamps, Pillars, and Spouts.—Tin, 300 lbs.; copper, 4 lbs.; antimony, 15 lbs.
Britannia, for Casting. — Tin, 100 lbs.; hardening, 5 lbs.; antimony, 5 lbs.
Lining' Metal, for Boxes of Railroad Cars.—Mix tin, 24 lbs.; copper, 4 lbs.; antimony, 8 lbs. (for a hardening); then add tin, 72 lbs.
Bronze Metal. — (1.) Copper,
7 lbs.; zinc, 3 lbs.; tin, 2 lbs. (2.) Copper, 1 lb.; zinc, 12 lbs.; tin, 8 lbs.
Artificial Gold. — Pure copper, 100 parts; zinc, or preferably tin, 17 parts; magnesia, 6 parts; sal-ammoniac, 3'6 parts; quicklime, 1'8 part; tartar of commerce, 9 parts. The copper is first melted, then the magnesia, salammoniac, lime, and tartar, are then added, separately and by degrees, in the form of powder; the whole is now briskly stirred for about half an hour, so as to mix thoroughly; and then the zinc is added in small grains by throwing it on the surface and stirring till it is entirely fused; the crucible is then covered, and the fusion maintained for about 35 minutes. The surface is then skimmed and the alloy is ready for casting. It has a fine grain, is malleable, and takes a splendid polish. Does not corrode readily, and for many purposes is an excellent substitute for gold. When tarnished, its brilliancy can he restored by a little acidulated water.
German Silver, First Quality for Casting.—Copper, 50 lbs.; zinc, 25 lbs.; nickel, 25 lbs.
German Silver, Second Qualitij for Casting. —Copper, 50 lbs.; zinc, 20 lbs.; nickel (best pulverized), 10 lbs.
German Silver, for Rolling.—Copper, 60 lbs.; zinc, 20 lbs.; nickel, 25 lbs. Us«d for spoons, forks, and table ware.
German Silver, for Bells and other Castings.—Copper, 60 lbs.; zinc, 20 lbs.; nickel, 20 lbs; lead, 3 lbs.; jron (that of tin plate being best), 2 lbs.
In melting the alloy for German silver it is difficult to combine a definite proportion of zinc with the compound of nickel and copper previously prepared. In fusing the three metals together there is always a loss of zinc by volatilization, which may be lessened by placing it beneath the copper in the crucible. The best method is to mix the copper and nickel, both in grains first, place them, thus mixed, in the crucible, when melted add the zinc and a piece of borax the size of a walnut. The zinc will gradually dissolve in the fluid copper, and the heat may be raised as their fluidity increases. In this instance, as in all others of forming alloys, it is profitable to mix the oxides of the various metals together, and reduce them under the protection of a suitable flux. The metal nickel can be produced only from pure oxide of nickel; and, as purity of the alloy is essential to good quality, the common commercial zinc is not sufficiently pure for forming argentan. Copper cannot well be used in the form of oxide, but grain copper or wire-scraps will serve equally as well.
Imitation of Silver. — Tin, 3 oz.; copper, 4 lbs.
Pinchbeck.—Copper, 5 lbs.; zinc, 1 lb.
Tombac.—Copper, 16 lbs.; tin, 1 lb.; zinc, 1 lb.
Red Tombac.—Copper, 10 lbs.; zinc, 1 lb.
Stereotype Metal.—1 tin; 1 antimony; 4 lead. In using stereotype metal, brush the type with plumbago or a small quantity of oil, then place in a frame, and take a cast with plaster of Paris. The cast is dried in a very hot oven, placed face downwards upon a flat plate of iron; this plate is laid in a tray or pan of iron, having a lid securely fastened, and furnished with a hole at each corner. Dip the tray in the fluid metal, which will flow in at the four corners. When the tray is lemoved, dip the bottom only in water; and as the metal contracts in cooling, pour in melted metal at the corners so as to keep up the fluid pressure, and obtain a good solid cast. When cool open the tray; remove the cake of plaster and metal, and beat the edges with a mallet to remove superfluous metal. Plane the edges square, turn the back flat, in a lathe, to the required thickness, and remove any defects. If any letters are damaged cut them out, and solder in separate types instead. Finally, fix upon hard wood to the required height.
Casting Stereo-Plates by the Paper Process.—Lay a sheet of tissue paper upon a perfectly flat surface, and paste a soft piece of printing paper, which must be presfed evenly on, to the tissue. Lay the paper on the form, previously oiled, and cover with a damp rag; beat with a stiff brush the paper in evenly, then paste a piece of blotting paper, and repeat the beating in; after which about three more pieces of soft tenacious paper must be pasted and used in a similar way; back up with a piece of cartridge paper. The whole must then be dried with moderate heat, under a slight pressure. When thoroughly dry, brush well over with plumbago or French chalk. When this is done it is ready for the matrix. This is a box of a certain size for the work required, the interior of which is type high. In it is what is termed a gauge, which lifts out to insert your paper cast, and is regulated by hand to the size of the plate required. This being placed inside, the lid is shut down and screwed tight, with the end or mouthpiece left open. By this orifice the metal is poured in, and, as it is mounted to swing, the box is moved about so as to well throw down the metal and make a solid cast. Then water is dashed on the box, the screw-bar unshackled, the lid lifted, the plate taken off, and the paper cast is again ready for work.
Fusible Metal.—1. Bismuth, 8 parts; lead, 5 parts; tin, 3 parts: melt together. Melts below 212° Fahr. 2. Bismuth, 2 parts; lead, 5 parts;
tin, 3 parts. Melts in boiling water 3. Lead, 3 parts; tin, 2 parts; bismuth, 5 parts: mix. Melts at 197° Fahr. Used for stereotyping; used to make toy-spoons, to surprise children by their melting in hot liquors; and to form pencils for writing on asses' skin, or paper prepared by rubbing burnt hartshorn into it.
Fusible Alloy, for Silvering Glass. — Tin, 6 oz.; lead, 10 oz.; bismuth, 21 oz.; mercury, a small quantity.
Muntz Metal.—6 parts copper; 4 zinc. Can be rolled and worked at a red heat.
Alloy for Cymbals and Gongs.—100 parts of copper with about 25 of tin. To give this compound the sonorous property in the highest degree, the piece should be ignited after it is cast, and then plunged immediately into cold water.
Alloy for Tam-Tams, or Gongs.—80 parts of copper and 20 of tin, hammered out with frequent annealing. An alloy of 78 of copper and 22 of tin answers better, and can be rolled out.
Alloy for Bells of Clocks.— The bells of the pendulcs, or ornamental clocks, made in Paris, are composed of copper 72-00, tin 26'56, iron 1-44 in 100 parts.
Bell Metal, fine.—71 copper, 26 tin, 2 zinc, 1 iron.
Bell Metal, for large Bells.—Copper, 100 lbs.; tin, from 20 to 25 lbs.
Bi:ll Metal, for small Bells.—Copper, 3 lbs.; tin, 1 lb.
Cock Metal.—Copper, 20 lbs.; lead, 8 lbs.; litharge, 1 oz.; antimony, 3 oz.
Alloy for Journal Boxes.— Copper, 24 lbs.; tia, 24 lbs.; and antimony, 8 lbs. Melt the copper first, then add the tin, and lastly the antimony. It should be first run into ingots, then melted and cast in the form required for the boxes.
Queen's Metal.—A very fine silver-looking metal is composed of 100 lbs. of tin, 8 of regulus of antimony, 1 of bismuth, and 4 of copper.