Cement for marble. Stir to a thick batter with silicate of soda 12 parts of Portland cement, 6 of slaked lime, 6 of fine white lead and 1 of infusorial earth. This is excellent for marble and alabaster. The cemented objects need to be heated. After 24 hours the fracture is firm, and the place can scarcely be found.
Cement for attaching wood, glass, etc., to metal. Acetate of lead 23 parts by weight, alum 23, gum arabic 38, wheat flour 250.
Dissolve the acetate of lead and the alum in a little water and separately dissolve the gum arabic in a fair quantity of boiling water. Thus if the 250 parts of wheat flour represent half a pound, the quantity of water needed will be about a pint. The gum having dissolved, add the flour, put the whole on the fire, stir well with a wooden stick, then add the solution of lead acetate and alum. Continue the stirring in order to avoid the formation of lumps, then take it off the fire without allowing it to boil. This cement is used cold, and will not scale. It is very useful in making wood, glass, cardboard, etc., adhere to metal, and is extremely strong.
Brushmakers’ cement. Rosin 5 lbs., rosin oil or spirit 1 quart.
Reduce the rosin to small pieces, run down in a pot, add the other ingredient, and stir until mixed and syrupy, then run out into tins. It is used for cementing the bristles in the stocks, also for string binding on sash tools, etc.
Cement for electrical apparatus. Mix together 1 lb. of beeswax added to 5 lbs. of rosin, 1 lb. of red ochre, and 2 tablespoonfuls of plaster of Paris. It will make an excellent composition for electrical apparatus.
A cheaper composition for cementing voltaic plates into wooden troughs is made with 6 lbs. of plaster of Paris and ¼ pint of linseed oil. The ochre and the plaster of Paris should be well dried and added to the other ingredients when these are in a melted state.
Jewelers’ cement. Dissolve over the water-bath 25 parts of fish glue in a small quantity of strong spirits of wine, add 2 parts of gum ammoniac; separately dissolve 1 part of mastic in 5 of spirits of wine. Mix the two solutions and keep them in well-stoppered bottles.
American cement for jewelers. Soak 4 ozs. of isinglass in 2 lbs. of water for 24 hours, then evaporate in the water-bath; to 1 lb. add 1 lb. of rectified spirits of wine, and strain. Then mix in a solution of 2 ozs. of mastic and 1 oz. of gum ammoniac in 16 ozs. of rectified spirit.
Cement for celluloid. Shellac 2 ozs., spirits of camphor 2, 90 per cent. alcohol 6 to 8.