Selective (brush) hard coating is a practical way of applying hard, wear resistant, and corrosion resistant hard coatings on aluminum. The coatings are comparable in quality to tank hard coats, and they meet most commercial and government specifications. The process may be used as a standard manufacturing method, to repair damaged tank hard coat, or to repair worn or mismachined aluminum surfaces.A new selective hard coat solution has been developed for this purpose during the course of a comprehensive research program. Extensive testing was conducted to determine the proper operating conditions for the solution. Current recommendations on equipment, supplies and procedures are made.