One additional item: Someone made the statement that cleaning is important. In fact, surface prep is the single most important part of a successful paint job. Soap and water and solvent cleaning go a long way (all properly dried), but I add an application of a phosphatizing agent (Ospho, Metal Clean, etc) for two reasons. First, the crystalline phosphate coating left by the treatment is an excellent adhesion promoter. And second, if this acidic water based coating does not wet the metal surface in spots, you still have a film of oil or grease on the surface that will prevent proper adhesion. Just don't be sloppy since these solutions are acidic and will etch metal surfaces. I learned a trick to check for proper surface cleanliness when I was making critical epoxy joints. If water won't wet the surface easily, the glue won't stick well. A squeeze bottle of water works on an engine block as well provided you dry it well after the test. Buy a hair dryer or hot air paint stripper. But let the metal cool to near room temperature before painting to prevent the solvent from flashing too rapidly. And do not paint when the humidity is up (above about 60-70%)since an adsorbed layer of moisture will form on the clean metal surface and this too will hurt paint adhesion. Drying the metal and cooling it during a "dry" day is better than painting it hot to prevent the adsorption of excessive moisture in the air.
