I guess they're aluminum? Mine have the white discoloration/mottling on them and I'd like to paint them but don't really know the best way to do it. I have no painting equipment so I guess it will be done with rattle cans, but what's the best way to do it? Do I NEED to strip them? Do they need primer? I'm just looking to return them to stock or as close as I can get. Any help would be appreciated.