(1) Melt carefully 40 parts of white wax, 80 of col-cothar and 160 parts by weight of finely pulverized colophony. Add to the mass when melting 20 parts by weight of Venetian turpentine. The mass is to be removed from the fire and the finished cement mixed until cold with a wooden spatula. This cement is to be applied when warm.
(2) Compound together equal quantities of finely powdered pumice and shellac and make application of same while warm.
(4) Take a good grade of sealing wax, taking pains that same is not too brittle. If there is any brittle-ness, remove same with a little Venetian turpentine. When the glass is cemented in a metallic case, both should be heated to the melting point of the sealing wax.
A cement for pieces of iron to iron which must be used soon after it is made is composed of 1 part flowers of sulphur. 2 parts sal-ammoniac, 60 parts powdered cast-iron bore chips. Stir into a stiff paste by the addition of water.
To cement iron to wood or stone, melt together 1 part of wax and 4 parts of black pitch, and mix into the melted mass 1 part of brick dust.
Two parts of pitch are to be melted and then 1 part of brick dust is stirred in. The cavity in the handle is filled with this compound and the tang of the blade is then forced in.
(1) To cement knives and forks in their handles, compound together 2 parts of pulverized colophony and 1 part of brick dust. The cavity in the handle is to be filled with this compound and then you force in the heated tang of the blade.
(2) Another cement which is equally good for this purpose and is applied in the same manner is made by melting together 1 part of sulphur and 4 parts of colophony; iron filings, brick dust or fine sand being mixed into the melted mass.
To cement metal plates on wooden boxes, melt together 1 part linseed oil and 6 parts resin and mix into the melted mass 1/2 part of plaster of paris and 1 part of burnt ochre.
Rubber, or gutta percha, may be cemented to metal by the following process: Take pulverized shellac and dissolve in ten times its weight of pure ammonia. In three days the mixture will be of the required consistency. The ammonia penetrates the rubber, and enables the shellac to take a firm hold; but as it all evaporates in time, the rubber is immovably fastened to the metal, and neither gas nor water will remove it.
The cement is composed of 5 pounds Paris white, 5 pounds yellow ochre, 10 pounds litharge, 5 pounds red lead, and 4 pounds black oxide of manganese, these various materials being mixed with great thoroughness, a small quantity of asbestos and boiled oil being afterward added. The composition as thus prepared will set hard in from two to five hours, and possess the advantage of not being subject to expansion and contraction to such an extent as to cause leakage afterward, and its efficiency in places difficult of access is of special importance. This is a cement of specially valuable properties for steam pipes, in filling up small leaks, such as a blow-hole in a casting, without the necessity of removing the injured place.