Читать книгу Henley's Formulas, Recipes and Processes (Applied Chemistry) - Various - Страница 225
Enameling Alloys.
Оглавление—I. Transparent.—This alloy should possess the property of transmitting rays of light so as to give the highest possible effect to the enamel. The alloy of gold for transparent green should be pale; a red or copper alloy does not do for green enamel, the copper has a tendency to darken the color and thus take away a part of its brilliancy. The following alloy for transparent green possesses about the nearest print, in color, to the enamel—which should represent, as near as possible, the color and brilliancy of the emerald—that can be arrived at:
| ozs. | dwts. | grs. | |
|---|---|---|---|
| Fine gold | 0 | 18 | 8 |
| Fine silver | 0 | 1 | 6 |
| Fine copper | 0 | 0 | 10 |
No borax must be used in the melting of this alloy, it being of a more fusible nature than the ordinary alloy, and will not take so high a heat in enameling.
II. Red Enamel.—The enamel which forms this color being of a higher fusing point, if proper care be not taken, the gold will melt first, and the work become ruined. In the preparation of red enamel, the coloring matter is usually an oxide of gold, and this so raises the temperature at which it melts that, in order to prevent any mishap, the gold to be enameled on should be what is called a 22-carat red, that is, it should contain a preponderance of copper in the alloying mixture so as to raise the fusing point of the gold. The formula is:
| ozs. | dwts. | grs. | |
|---|---|---|---|
| Fine gold | 0 | 18 | 8 |
| Fine silver | 0 | 0 | 10 |
| Fine copper | 0 | 1 | 6 |
