Colored Varnish for Sheet Iron and Tin Plates.

The Manufacturer and Builder, 1888

Rub to a fine powder 30 parts of crystallized acetate of copper (verdigris), and leave it exposed, spread out in a thin layer for several days in a moderately warm place. Grind the resulting browninsh powder with a little oil of turpentine, to which add 100 parts of hot copal varnish previously heated to 120°M Fag. Let it stand for several days in a warm place, with occasional shaking; finally, let it deposit. By application of three or four coats of this varnish on iron or tin, a dark-green color is produced. Two coats, followed by a heating in a suitable drying oven, will yield different colors and shades of color, according to the length of exposure in the oven, the tints varying from light or dark gold to orange and brownish-red.