Sounds like you don't want to seal the metal as much as you wish to coat it. Dr. Gaddy used Behlen's spray lacquer on newly cased frames; available from any good woodworking supply. Dr. Gaddy also used TruOil for an easier finish (can apply without disassembling or masking the gun, easy to refresh when it begins to wear). Galazan/CSMC sells a case protection lacquer; I think it comes is a kit of some sort. Don't know where in AZ you are, but there is a big automotive paint supplier in Yuma (don't remember the name, but they are in the Yellow Pages), and they may have lacquer for clear coats. Be very specific about what you want to do, because most clear coats are catalyzed, either polyester or epoxy, and some are water-based (that's a no-no). If you have the gun disassembled, you may want to use a catalyzed finish, and maybe even a baked finish (something like the various GunKote type products that are out there). Caution: nitrocellulose lacquer (like the Behlen's) is easy to work with and easy to remove/refresh. Catalyzed products are difficult to work with and almost impossible to remove. Whatever you use, keep it thin. I would go with Behlen's if the gun is apart, or Truoil if the gun is assembled.
