Abstract: Filiform corrosion of aluminum and of chrome-plated steel is prevented by covering the surface of the bare metal with a powder coating containing a major amount of a thermosetting resin selected from the group consisting of polyurethanes, polyesters, and acrylics; a minor, adhesion promoting amount of an epoxy resin; and either an ultra-violet light absorber or a hindered amine light stabilizer or a mixture of both, and baking the coated article to give a clear coating on the metal.

Abstract: A filiform corrosion resistant aluminum automotive road wheel has a bare aluminum surface, optionally having a chromate conversion coating, which is covered with a thermoset clear coating. The thermoset clear coating is the thermally cured product of a powder coating composition consisting essentially of (1) a major amount of a thermosetting resin selected from the group consisting of polyurethanes, hydroxy functional polyesters, and glycidyl functional acrylic resins, (2) a curing agent, (3) from about 1% to about 5% by weight of the coating powder of an epoxy resin as an adhesion promoting additive, and (4) either an ultra-violet light absorber or a hindered amine light stabilizer or a mixture of both.