For aluminum you are going to want white polishing compound for final polish, blue for final polish/ mild cutting compound. If you need cutting compound you want red or black compound. If your aluminum is in real bad shape sand the aluminum piece with 400 grit sandpaper in one direction where it looks like straight line sand Mark's, then hit with blue polishing compound then move to your white polishing compound. Presto like a mirror!!! If you need to know what pads for the different compounds, just shoot me a reply back.