Fancy Coloring of Metals.

Manufacturer and builder 11, 1869

The coloring matter of small objects in metal has recently occupied the attention of manufacturers and chemists, and M. Puscher, a German chemist, gives the following recipes for the application of sulphur to the purposes referred to:

1. A solution is made in the following manner: Dissolve four ounces of the hypo-sulphite of soda in a pint and a half of water, and then add a solution of one ounce of acetate of lead in the same quantity of water. Articles to be colored are placed in the mixture, which is then gradually heated to boiling point. The effect of this solution is to give iron the effect of blue steel; zinc becomes bronze; and copper or brass becomes, successively, yellowish, red, scarlet, deep blue, light blue, bluish white, and, finally, white, with a tinge of rose. This solution has no effect on lead or tin.

2. By replacing the acetate of lead in the solution by sulphate of copper, brass becomes first of a fine rosy tint, then green, and, finally, of an iridescent brown color. Zinc does not color in this solution; it throws down a precipitate of brown sulphuret of copper, but if boiled in a solution containing both lead and copper, it becomes covered with a black adherent crust, which may be improved by a thin coating of wax.

 3. If the lead solution be thickened with a little gum tragacanth, and patterns be traced with it on brass, which is after-wards heated to 212 degrees, and then plunged in solution No. 1, a good marked effect is produced.

Ei kommentteja :