Bright Dipping of Copper

A bright golden color can be obtained for copper-zinc alloys by a half-minute immersion in a cold mixture of sulfuric and nitric acids, a typical solution being 30 percent nitric acid, 30 percent sulfuric acid and 40 percent water by volume. A more yellow color can be obtained by dipping brass in a solution of dilute sulfuric acid with either chromic acid or a dichromate addition.