Acid Salt W is a water-soluble dry acid which may be used in place of sulfuric or hydrochloric acids in a pre-plate line, or acid pickling line. Acid Salt W may be used as the acid in operations which process ferrous metals, brasses, copper, copper alloys, zinc die castings, white metals, nickel plated surfaces, lead alloys, stainless steel, pewter, nickel alloys, titanium and titanium alloys. Acid Salt W has been formulated for immersion application, or as a cathodic pickle.