GB330040A - Process for the production of firmly adhering electrolytic metal deposits upon articles plated in the molten bath - Google Patents

Abstract

330,040. Stefke, H. March 26, 1929. Lead and other metals, depositing; metals, pickling; preparing surfaces ; treating after electrolysis.-An article plated by immersion in molten metal is treated in a solution of neutral, alkaline, or acid metal salts or a suitable acid until the crystal structure of the plating stands out clearly; it is then electro-plated in a neutral, alkaline, or acid bath of the same metal, the crystal structure remaining preserved during the plating. The liquid employed in the pre. liminary treatment may be a hot solution of sodium chloride or zinc chloride, or fluosilicic, acetic, or phenol-sulphonic acid. The liquid employed may constitute the plating-bath, the current being switched on after the crystal structure has been revealed ; alternatively the article may be connected as anode during the preliminary treatment. A bath for treating and plating an article coated by insertion in molten lead consists of a solution of lead fluosilicate, acetate or phenol-sulphonate together with 10 per cent of the corresponding free acid or a mixture of these salts and acids. Articles so plated may be soldered with soft solder. A further plating of nickel, copper, cadmium, brass, tin or silver may be applied. Articles of iron or copper and its alloys may be electro-plated with a metal of the iron or copper group before coating with molten lead.