Then polish the articles and rub them
over with a cloth and fine pumice powder, to roughen the surface
slightly. Finally, to remove all traces of grease, dip the
articles to be plated in a boiling potash solution made by
dissolving 4 oz. American ash in 1-1/2 pt. of water. Do not touch
the work with the hands again. To avoid touching it, hang the
articles on the wires, by which they are to be suspended in the
plating bath, before dipping them in the potash solution; then
hold them by the wires under running water for ten minutes to
completely remove every trace of the potash.
For plating with copper prepare the following solution: 4 oz.
copper sulphate dissolved in 12 oz. water; add strong ammonia
solution until no more green crystals are precipitated. Then add
more ammonia and stir until the green crystals are re-dissolved
giving an intense blue solution. Add slowly a strong solution of
potassium cyanide until the blue color disappears, leaving a clear
solution; add potassium cyanide again, about one-fourth as much in
bulk as used in the decolorizing process. Then make the solution
up to 2 qt.
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