Abstract: Surface oxides, such as copper, zinc and aluminum oxides, are effectively removed from copper-base alloys by a process comprising:(a) contacting the alloy surface with an aqueous solution containing potassium ions, e.g. a solution prepared by dissolving potassium hydroxide in water; and(b) subsequently contacting the alloy surface with an aqueous solution comprising an acid, a peroxide, and a metal oxide, e.g. a solution of sulfuric acid, hydrogen peroxide and molybdic acid, the solution having:(i) an acid equivalent of a sulfuric acid solution of about 4 to 30 percent by volume;(ii) a peroxide concentration of about 1 to 30 percent by volume; and(iii) a metal oxide concentration of about 0.1 to 5 percent by volume.