That's good info too know ! I would've thought to sand the anodizing off !Sand very lightly, the anodized coating is a lot better for promoting paint adhesion than bare aluminum itself, so you don't want to sand through.
Hmmm, didn't know that but I use it often.If you want to strip the anodizing layer off there are commercial strippers available and Easy Off oven cleaner will also work. Easier than sanding.
Mike