Cements and Glue.

Armenian Glue.

The jewellers of Turkey, who are mostly Armenians, have a singular method of ornamenting watch cases, etc., with diamonds and other precious stones by simply gluing or cementing them on. The stone is set in gold or silver and the lower part of the metal made flat, or to correspond to that part to which it is to be fixed. It is then warmed gently and the glue applied, which is so very strong that the parts thus cemented never separate. For this glue, which will firmly unite bits of glass and even polished steel, and which may of course be applied to a vast variety of useful purposes, large number of formulas have been published. The following is the original recipe. Dissolve 5 or 6 bits of gum mastic, each the size of a large pea, in as much alcohol as will suffice to render them liquid; in another vessel dissolve as much isinglass, previously softened a little in water (though none of the water must be used), in good brandy or rum as will make a two-ounce vial of very strong glue, adding two small bits of galbanum or ammoniacum, which must be rubbed or ground until they are dissolved. Then mix the whole with a sufficient heat. Keep the glue in a vial closely corked, and when it is to be used set the vial in boiling water. To avoid cracking the vial by exposure to such sudden heat use a thin green glass vial and hold it in the steam for a few seconds before immersing it in the hot water.—Workshop Receipts.

Glutina Cement.

FOR GLASS, CHINA, WOOD, LEATHER, ETC.

Gelatine (Cooper’s or Cox’s)3 ounces.
Acetic acid2 ounces.
Carbolic acid5 grains.
Oil of cloves6 minims.
Water enough to make1 pint.

Soak the gelatine in half a pint of water for four hours. Place in a bottle and heat in a water bath; add the acids, dissolve, add the oil of cloves and sufficient hot water to make a pint, and strain.

To Cement Iron to Iron.

Powdered cast-iron bore chips60 parts.
Sal-ammoniac2 parts.
Flowers of sulphur1 part.

Mix, and stir the mixture into a stiff paste by adding water. Use while fresh.

Cementing Metal to Glass, Stone, Etc.

For attaching metal plates, such as metal letters, etc., to flat sheets of glass or windows, the following is excellent:

Copal varnish15 parts.
Drying oil5 parts.
Turpentine3 parts.

Melt in a water bath, and add 10 parts of slaked lime. The cement commonly used for fastening the tops on kerosene lamps is plaster of Paris, which is porous, quickly penetrated by the kerosene, and readily destroyed. A cement which does not have 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 mix with half its weight of plaster of Paris. Use while fresh.