Читать книгу Henley's Formulas, Recipes and Processes (Applied Chemistry) - Various - Страница 46
Sign-letter Cements.—
Оглавление| I.— | Copal varnish | 15 parts |
|---|---|---|
| Drying oil | 5 parts | |
| Turpentine (spirits) | 3 parts | |
| Oil of turpentine | 2 parts | |
| Liquefied glue | 5 parts |
Melt all together on a water bath until well mixed, and then add 10 parts slaked lime.
II.—Mix 100 parts finely powdered white litharge with 50 parts dry white lead, knead together 3 parts linseed oil varnish and 1 part copal varnish into a firm dough. Coat the side to be attached with this, removing the superfluous cement. It will dry quickly and become very hard.
| III.— | Copal varnish | 15 parts |
|---|---|---|
| Linseed-oil varnish | 5 parts | |
| Raw turpentine | 3 parts | |
| Oil of turpentine | 2 parts | |
| Carpenters’ glue, dissolved in water | 5 parts | |
| Precipitated chalk | 10 parts | |
| IV.— | Mastic gum | 1 part |
| Litharge, lead | 2 parts | |
| White lead | 1 part | |
| Linseed oil | 3 parts |
Melt together to a homogeneous mass. Apply hot. To make a thorough and reliable job, the letters should be heated to at least the temperature of the cement.
