The only permanent solution would be clearcoat,satin maybe.Other than that ,depending on how new or shiny you want the metal to look, I will be going with a oil / wax mixture to keep mine from getting rusty ,but it already has some pitted dark areas. There is a metal prep you can spray on, keeps it from rusting ,its for welding ,was on one of the TV car shows, don't know how it would last outside with rain,etc. tho. Just some ideas, I am sure there are more some other things that work.