Cement for knife handles. Melt together 20 parts of rosin, 5 of sulphur, and 8 of iron filings.
Pour some of the hot mixture into the handle, and then push in the knife previously heated.
Cement for petroleum lamps. Boil 12 parts of rosin in 16 of strong lye until it is entirely dissolved and on cooling forms a tenacious solid mass. Dilute this with 20 parts of water, and carefully work into it 20 parts of plaster of Paris. This cement is insoluble in petroleum, and is especially adapted for cementing the glass parts of lamps to the metal. It is also a good material for stoppers for petroleum bottles.
Cement for porcelain. Rosin, 14 parts; elemi, 7; shellac, 7; mastic, 7; sulphur, 42; brick dust, 20.
Cement for porcelain which is to be heated. Heat carefully 10 parts of amber in a large spoon, stirring constantly, until it evolves heavy vapors of a strong odor. Rub the melted mass as finely as possible, and after placing the powder in a bottle pour over it a mixture of bisulphide of carbon and benzine. Close the bottle air-tight to prevent the evaporation of the very volatile solvent. When the powder is dissolved remove the cork and replace it by one provided with a small brush. The application of the cement and pressing together of the parts to be cemented must be effected as quickly as possible. In articles properly cemented the joint can only be detected by the closest examination. This cement holds so well that cups and saucers, soup-tureens, etc., mended with it can be used for years.
Cement to withstand the action of petroleum. Dissolve 5 parts of shellac, 1 of turpentine in 15 of petroleum. This cement is quite elastic.
Cement for mica. A colored cement for joining sheets of mica is prepared as follows: Soak clean gelatine in water, and when swelled squeeze out the excess of water by pressure between a cloth, then melt the gelatine by the heat of a water-bath, and stir in just enough proof spirit to make it fluid. To each part of this solution add, while stirring, ¼ oz. of gum ammoniac and 1½ ozs. of gum mastic dissolved in 4 ozs. of rectified alcohol. Put the mixture into bottles, and when required for use stand the bottle in hot water. This cement resists cold water.
Cement for horn, whalebone and tortoise shell. Dissolve gum mastic 10 parts and turpentine 4, in 12 of linseed oil. Apply hot.
Cement for terra-cotta articles. Melt together 70 parts of rosin, 70 of wax and 16 of sulphur, and stir into the mass 8 parts of hammer slag and 8 of quartz sand. Coat the fractured surfaces with oil of turpentine, apply the cement as quickly as possible, and press the surfaces together. It is advisable to heat the terra cotta previously to 158° or 176° F. After cementing the article, smooth the joint with a heated knife and dust very fine terra-cotta powder through a linen bag upon the soft cement in order to give it exactly the same color as the article itself.
Mastic cement for glass. Gum mastic 15 parts, bleached shellac 10, turpentine 5.