Henley's Twentieth Century Formulas, Recipes and Processes. Various

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СКАЧАТЬ and during the cooling, first, the cadmium; second, the bismuth; third, the tin. It is absolutely necessary to proceed in this manner, since these metals fuse at temperatures ranging from 850° F. (for lead), to 551° F. (for tin).

      Fusible Safety Alloys for Steam Boilers.—

	Bismuth	Lead	Zinc	Melt­ing point	At­mos. pres­sure
I.	8	5	3	212° F.	1
II.	8	8	4	235° F.	1.5
III.	8	8	3	253° F.	2
IV.	8	10	8	266° F.	2.5
V.	8	12	8	270° F.	3
VI.	8	16	14	280° F.	3.5
VII.	8	16	12	285° F.	4
VIII.	8	22	24	309° F.	5
IX.	8	32	36	320° F.	6
X.	8	32	28	330° F.	7
XI.	8	30	24	340° F.	8

      Lipowitz Metal.

      —This amalgam is prepared as follows: Melt in a dish, cadmium, 3 parts, by weight; tin, 4 parts; bismuth, 15 parts; and lead, 8 parts, adding to the alloy, while still in fusion, 2 parts of quicksilver previously heated to about 212° F. The amalgamation proceeds easily and smoothly. The liquid mass in the dish, which should be taken from the fire immediately upon the introduction of the mercury, is stirred until the contents solidify. While Lipowitz alloy softens already at 140° F. and fuses perfectly at 158°, the amalgam has a still lower fusing point, which lies around 143 3/5° F.

      This amalgam is excellently adapted for the production of impressions of various objects of nature, direct impressions of leaves, and other delicate parts of plants having been made with its aid which, in point of sharpness, are equal to the best plaster casts and have a very pleasing appearance. The amalgam has a silver-white color and a fine gloss. It is perfectly constant to atmospheric influences. This amalgam has also been used with good success for the making of small statuettes and busts, which are hollow and can be readily gilt or bronzed by electro-deposition. The production of small statues is successfully carried out by making a hollow gypsum mold of the articles to be cast and heating the mold evenly to about 140° F. A corresponding quantity of the molten amalgam is then poured in and the mold moved rapidly to and fro, so that the alloy is thrown against the sides all over. The shaking should be continued until it is certain that the amalgam has solidified. When the mold has cooled off it is taken apart and the seams removed by means of a sharp knife. If the operation is carried on correctly, a chasing of the cast mass becomes unnecessary, since the alloy fills out the finest depressions of the mold with the greatest sharpness.

      Amalgam For Plaster.

      —Tin, 1 part; bismuth, 1 part; mercury, 1 part. Melt the bismuth and the tin together, and when the two metals are in fusion add the mercury while stirring. For use, rub up the amalgam with a little white of egg and brush like a varnish on the plaster articles.

      Plastic Metal Composition.

      —I. Copper oxide is reduced by means of hydrogen or copper sulphate by boiling a solution of the same in water with some zinc filings in order to obtain entirely pure copper. Of the copper powder obtained in this manner, 20, 30, or 36 parts, by weight, according to the degree of hardness desired for the composition (the greater the quantity of copper used the harder will the composition become), are thoroughly moistened in a cast-iron or porcelain mortar with sulphuric acid of 1.85 specific gravity; 70 parts, by weight, of mercury are then added to this paste, the whole being constantly stirred. When all the copper has been thoroughly amalgamated with the mercury, the sulphuric acid is washed out again with boiling water, and in 12 hours after it has become cold the composition will be so hard that it can be polished. It is impervious to the action of dilute acids, alcohol, ether, and boiling water. It contains the same specific gravity, alike in the soft or the hard condition. When used as a cement, it can at any time be rendered soft and plastic in the following manner: If applied while hot and plastic to the deoxidized surfaces of two pieces of metal, these latter will unite so firmly that in about 10 or 12 hours the metal may be subjected to any mechanical process. The properties of this composition render it very useful for various purposes, and it forms a most effective cement for fine metal articles which cannot be soldered in fire.

      II.—Bismuth, 5.5 parts; lead, 3; tin, 1.5.

      III. Alloy d’Homburg.—Bismuth, {66} 3 parts; lead, 3; tin, 3. This alloy is fusible at 251° F., and is of a silvery white. It is employed for reproductions of medals.

      IV. Alloy Valentine Rose.—Bismuth, 4 to 6 parts; lead, 2 parts; tin, 2 to 3 parts. This alloy fuses at 212° to 250° F.

      V. Alloy Rose père.—Bismuth, 2 parts; lead, 2; tin, 2. This alloy fuses at 199° F.

      The remainder are plastic alloys for reproducing cuts, medals, coins, etc.:

      VI.—Bismuth, 4 parts; lead, 2 parts; tin, 1 part.

      VII.—Bismuth, 3 parts; lead, 3 parts; tin, 2 parts.

      VIII.—Bismuth, 4 parts; lead, 2 parts; tin, 2 parts.

      IX.—Bismuth, 5 parts; lead, 2 parts; tin, 3 parts.

      X.—Bismuth, СКАЧАТЬ