(4) A fire and water proof cement is made by stirring intimately together 2 parts iron filings free from oxide. 5 parts of clay thoroughly dried and pulverized, 1/2 part borax, 1/2 part salt, 1 part of peroxide of manganese. These are made as fine as possible by stirring and then reduced to a thick paste. This cement must be used as soon as it is made. After it has been applied, it should be exposed to a gradually increasing heat that rises almost to a white heat.
Another fire and water proof cement is made by the addition of enough soluble glass to equal parts of pulverized zinc-white and sifted peroxide of manganese to form a thin paste. This cement must also be used as soon as it is made.
(5) Cement which resists heat and water is composed of the following: Lime, 10 parts; iron filings, 5 parts; vinegar, 2 parts; water, 3 parts.
A cement for air-tight oven door, which must be used as soon as made, is composed by homogeneously combining 120 parts of iron filings, 1 of flowers of sulphur, 8 of powdered feldspar and 2 of pulverized sal-ammoniac made into a paste by the addition of water.
To make a good cement or paste for pasting asbestos to tin hot-air furnace pipes. Take 2 parts litharge, 1 part dry slacked lime, and 1 part fine, dry sand. Combine them thoroughly, and add enough hot linseed oil to form a paste-like mass. It sets hard and quickly, and must be freshly prepared every time it is required for application, which application must be made only when the cement is hot.
A cement for use in blast pipes, hot-blast stoves, blow engines, etc., is composed of clay, 1 part; common salt, 1 part; iron filings, 15 parts. Mix with equal parts of vinegar and water.
Cement for brass and glass is made thusly: One part of wax and 5 parts of resin are melted, and into this mass are stirred 1/4 part of plaster of paris and 1 part burnt ochre.
(2) Melt together 1 part of wax, 4 parts of resin-preferably pine resin - and stir into the melted mass 1 part of elutriated chalk or brick dust. Both these cements are to be applied warm to heated surfaces.
(3) For cementing brass on glass, knead a quantity of plaster of paris into twice the same quantity of resin soap, which is made by boiling 3 parts of resin and one part of caustic soda in 5 of water. This cement is used to a large extent for fastening brass tops on glass lamps. This is very strong, is unaffected by petroleum, bears heat excellently and becomes hard in from 1/2 to 3/4 of an hour. It will harden more slowly when slaked lime, white lead or zinc-white is used in place of the plaster of paris.
A cement to unite card to tin is made as follows: Boil 1 ounce of borax and 2 ounces of powdered shellac in 15 ounces of water until the shellac is entirely dissolved.
A good cement for filling faults in casings is made as follows: Iron filings free from rust, 10 parts; sulphur, 1/2; sal-ammoniac, 0.8; these are mixed with water to a thick paste, which is rammed into the "faults." This becomes strong when the iron filings are rusted. The parts which have to be cemented are treated before the operation with liquid ammonia, so as to be perfectly free from grease.