I've got the same set-up and have experienced the same problems. Had I known they were going to do this I would have bought painted cans. I use mothers metal polish which cleans thum up, but it is a long tedious job and doesn't last long. I posed this question before and someone suggested a product used on motercycles to seal them,
http://www.stylinconcepts.com/parts.cfm?PartFamilyID=798 but at $130 I decided to pass. If you find an easy way to clean these be sure to post!
Linear Mode
