To restore burnst steel tools, melt together 4 ounces of black pitch and 1 pound tallow, and then add, with constant stirring, 4 ounces of yellow prussiate of potash, 12 drachms of soap, a handful of common salt and 13 ounces of sal-ammoniac. Immerse the articles, heated red-hot, in this compound; allow them to cool and then harden them again, as customary.
(2) Another compound consists of:
5 parts Fish Oil, 2 parts Tallow, 10 parts Resin, 1/4 part Asafoetida.
Butter of antimony is made by heating a tri-sulphide with mercuric chloride.
For case-hardening cast-iron, take salt. 21 pounds; saltpetre, 1/2 pound; rock alum, 1/8 pound; ammonia, 4 ounces; salt of tartar, 4 ounces; pulverize all together and incorporate thoroughly. Use by powdering all over the iron while hot, then plunging in cold water.
A good case-hardening for iron consists of:
18 parts Sal-soda,
4 parts Muriate of Soda,
1 part Black Oxide of Manganese, 16 parts Lampblack.
Black iron cement for iron ovens is composed of the following: Iron filings (10 parts), sand (12 parts), bone black (10 parts), slaked lime (12 parts), lime milk (5 parts).
The bituminous or black cement for bottle corks consists of pitch hardened by the addition of rosin and brick dust.
The so-called Diamond cement for use in steam apparatus, steam boilers, etc., is made of 50 parts prepared graphite, 16 parts litharge, 15 parts whiting and 16 parts of linseed oil varnish.
A cement for use in fixing electrical or chemical apparatus is prepared by the mixture of 2 ounces plaster of paris, 1 pound of wax, 1 pound of red ochre, 5 pounds of rosin; the entire mass being melted at a moderate heat.
Evan's Metallic Cement is made by the dissolution of a cadmium amalgam prepared from 25 99-100 parts cadmium and 74 1-100 parts mercury in an excess of mercury, the solution being slightly packed in a leather bag and intimately kneaded. This kneading, particularly in cases where the cement has been previously heated to about 97 degrees Fahrenheit, makes the same very plastic and similar to softened wax.
Fire-proof cement is made as follows: To 4 or 5 parts of clay, thoroughly dried and pulverized, add 2 parts of iron filings free from oxide, 1 part of peroxide of manganese, 1/2 of sea salt and 1/2 of borax. Mix these ingredients thoroughly and render them as fine as possible, then reduce them to a thick paste with the necessary quantity of water, mixing intimately. It must be used immediately. After application it should be exposed to the heat, gradually increasing to almost a white heat. This cement is very hard.
(2) To equal parts of sifted peroxide of manganese and pulverized zinc white add a sufficient quantity of commercial soluble to form a thin paste. This mixture, when used, immediately forms a cement quite equal in hardness to that obtained by the first method.
(3) Take equal parts pulverized zinc white and sifted peroxide of manganese, and make into a paste with soluble glass.