This is a very valuable cement for large objects, such as shells, fossils, etc.: Beeswax, 1 oz.; resin, 4 oz.; powdered plaster-of-Paris, 5 oz. Melt together. To use, warm the edges of the specimen, and use the cement warm.
(1) For wooden vessels. A mixture of lime, clay, and iron oxide, separately calcined, and reduced to fine powder, then intimately mixed, kept in a close vessel, and made up With the requisite quantity of water when wanted. (2) For wood. The following cement will be as hard as stone when dry, and will adhere firmly to wood. Melt 1 oz. resin and 1 oz. of pure yellow wax in an iron pan, and thoroughly stir in 1 oz. of Venetian red, until a perfect mixture is formed. Use while hot. (3) For cracks in wood, (a) Slaked lime, 1 part; rye meal, 2 parts; made into a paste with a sufficient quantity of linseed oil; (6) Glue, 1 part, dissolved in water, 16 parts; when almost cold, sawdust and prepared chalk are stirred in to the required consistence; (c) Oil varnish, thickened with a mixture of equal parts white lead, red lead, litharge, and chalk.
This cement consists of 19 parts of sulphur, and 42 of Spowdered glass or earthenware, mixed thoroughly together by heating the sulphur. It may be used instead of hydraulic cement for uniting stones or bricks, and for cementing inn rods into holes cut in stone.
This is probably the purest form of gelatine or animal glue, and it makes one of the strongest cements known. As a cement, it may be treated like glue. From the fact that it is made from the sounds of fishes, it is sometimes called fish-glue.
The American or Diamond cement unites pieces of ivory with great firmness, but where a white cement, of nearly the same colour as ivory is required, the following modification will be found useful: (1) Dissolve 1 part of isinglass and 2 of white glue in 30 of water; strain and evaporate to 6 parts, then add 1/30 part of gum mastic, dissolved in 1/2 part of alcohol, and add 1 part of zinc white. When required for use, warm and shake well. The broken edges to be joined must also be warmed.
This is simply a paste made of fine rice flour, well boiled and ground in a mortar.
It sometimes happens that jewellers, in setting precious stones, break off pieces by accident; in this case they unite the parts so that the joint cannot be easily seen, with gum mastic, the stone being previously made hot enough to melt it. By the same medium, cameos of white enamel or coloured glass are often joined to a real stone as a ground, to produce the appearance of an onyx. Mastic is like wise used to cement false backs or doublets to stones, to alter their hue. (Ure.) The term Jewellers' Cement is also applied to Armenian Cement, which see. (1) Shellac, melted and run into sticks as large as quills. Used for joining glass, earthenware, etc.; the edges are heated sufficiently to melt the cement, which is then applied, and the joint is made while the heat lasts. (2) Tears of gum mastic employed in the same way. (3) Shellac, 2 parts, Venice turpentine, 1 part; fused together and formed into sticks. Used as the preceding.
The cement commonly used for fastening the tops on kerosene lamps is plaster-of-Paris, which is porous, quickly penetrated by the kerosene, and soon destroyed. Another cement which has not this defect is made by boiling 3 parts of resin, and 1 of caustic soda in 5 of water. This composition forms a soap, which, when mixed with half its weight of plaster-of-Paris, sets firmly in about § hour. It is said to be of great adhesive power, not permeable by kerosene, a low conductor of heat, and but superficially attacked by hot water.
The following lutes are used to stop holes and cracks in mahogany furniture: - (1) Beeswax, 4 oz.; melt and add Indian red, 1 oz.; and enough yellow ochre to produce the required tint. (2) Shellac melted and coloured as above, very hard.
Consists of mucilage of gum arabic, thickened with starch powder or farina, with the addition of a little lemon-juice. Sometimes the mucilage is used alone. This cement is employed by naturalists, for mounting specimens; by artificial flower makers; by confectioners, to stick ornaments on their cakes, etc.
The cements obtained from the following formula; are used by opticians for fixing lenses, prisms, etc, to chucks and holders, while they are being ground. (1) Pitch, 5 parts; wood ashes, 1; tallow, 1, less or more, according to the temperature of the season. (2) Shellac softened with rectified spirit or wood naphtha. (3) Beeswax, 1 oz.; resin, 15 oz.; melt and add 5 oz. of whiting previously heated red hot and still warm. (4) Resin, 1 lb.; melt and add dry and warm plaster 4 oz. This forms a very strong cement for rough purposes.
Parabolic - This is a variety of casein or cheese cement, prepared as follows: Curdle skim-milk with rennet or vinegar, press out the whey, and dry the curd by a very gentle heat, but as quickly as possible. When quite dry, grind it in a pepper or coffee mill, and triturate it in a mortar until reduced to a very fine powder. Mix 10 parts by weight of this powder with 1 of quicklime, also in very fine powder, and to every ounce of the mixture add 5 or 6 gr. of camphor. Triturate the whole together, and keep in phials well corked. Used to unite glass, earthenware, etc, which it does very strongly. It is made into a paste with a little water as wanted, and applied immediately. See Casein.