Abstract: This invention is a zincating process of aluminum surfaces for subsequent plating in which the aluminum surfaces are cleaned, contacted with an acidic etching solution comprising a peroxygen compound, the acidic etching solution being substantially free of corrosive nitrate compounds, and contacting the aluminum surfaces with a zincate solution containing 6-60 g/l zinc and 100-500 g/l hydroxide ion. The acidic etching solution is substantially free of toxic inorganic fluoride compounds in order to simplify waste treatment. This invention may be understood with reference to FIG. 2, in particular Step 6.