This study reports on the protection offered to steel and aluminum by selected formulations of fluidized-bed-applied vinyl, epoxy, polyester, ethylene-acrylic acid copolymer, and nylon powder coatings; solvent-borne vinyl, epoxy and chlorinated rubber coatings; ceramic coatings; hot-dipped and flame-sprayed zinc and aluminum coatings; and flame-sprayed 67-33 zinc-aluminum coatings. Most of the coatings fully protected the metals when exposed for ten years to a polluting industrial atmosphere. Some of the solvent-borne organic and flame-sprayed metallic coatings protected the metals during eleven years on a North Carolina ocean beach. Some of the flame-sprayed metallic coatings protected the metals during twelve years of Florida saltwater and mud exposure. The aluminum substrate panels retained their structural integrity whether exposed with or without coatings.