Cement for glass and porcelain. Mix quickly 50 parts of plaster of Paris, 10 of quick lime, and 20 of white of egg. Use at once, as the cement solidifies very rapidly.
Cement for iron and stone. A very useful cement for securing iron railing in stone is obtained by mixing 30 parts of plaster of Paris, 10 of iron filings and 20 of vinegar.
Cements for porcelain. I. Mix plaster of Paris with saturated solution of alum to a cream. After moistening the fractured surfaces apply a thin layer of the cement, press the surfaces together, wrap a wire or cord tightly around them, and let the article stand quietly for a few weeks. The cement is converted into a mass as hard as stone.
II. Mix plaster of Paris with a thick, clear solution of gum arabic and cement the articles as soon as possible. Although this cement adheres very tightly, porcelain vessels cemented with it cannot be used for liquids.
Universal plaster of Paris cement. Mix 21 parts of plaster of Paris, 3 of iron filings, 10 of water, and 4 of white of egg. This cement is suitable for attaching metal to glass, metal to stone, etc.
IRON CEMENTS.
Heat-resisting cement. Clay 10 parts, iron filings 5, vinegar 2, water 3.
Water and steam-proof cement. Iron filings 100 parts, sal-ammoniac 2, water 10.
This cement rusts very much in a few days, and is converted into an extremely solid mass which is perfectly steam- and water-proof.
Cement for iron. Mix 65 parts of wrought-iron filings, 2.5 of sal ammoniac, and 1.5 of flowers of sulphur, and then add 1 part of sulphuric acid diluted with sufficient water to form a stiff paste. This cement solidifies in two to three days, and rusts, with the parts of iron to be cemented, to an extraordinarily durable mass.