Acid pickle is generally the final cleaning stage prior to plating. Pickling is the removal of surface oxides (scale) and other contaminants such as dirt, and tarnish films by chemical immersion (nonelectrolytic). Pickling also activates the metal surface in preparation for plating and provides a light etch for better adhesion. In many operations pickle baths are also used to strip coatings such as zinc or cadmium. Such practices should be carefully examined and the impact on treatment, waste disposal, solution life, and recovery potential determined. In cases where heavy, tenacious scales are encountered, a preliminary pickle procedure may be required using the same or a different acid solution. In other cases, a brief acid dip to neutralize the residual alkaline cleaner film and activate the surface may suffice. In many cases, mechanical methods of descaling such as grit blasting and glass bead blasting may provide a superior, more economical alternative to acid pickling.