i have a aluminum bicycle the first time i painted it i painted over the original paint(didnt know any better). The second time i sanded it down with some paint left on it. Now this time im sanding it but im using 60grit it looks good to me is 60 grit to much.
you dont sand aluminum you strip it!
Home or do-it-yourself spray jobs most of the time come out looking like - fill in word of your choice. Why? Because the person hasn't done their homework in advance. First, you will need to strip the bike down to the bare frame - remove everything. Are you qualified to do all of this? Do you have all the tools needed? The next best step would be to have the frame professionally sand blasted, powder-coated clear coated by possibly an auto body shop that does this kind of thing on the side. Can't do that? Consult Google link below. So much FREE information on the Internet, it's amazing.
You screwed up. 60 grit should NEVER come in contact with aluminum... those scratches will never come out. NEVER have an aluminum frame sandblasted. You'll need to have it soda blasted or walnut shell blasted. You should be using 220 grit ALUMINUM OXIDE paper- it is white in color. My bet is that you are using garnet- the brown stuff, or maybe coated paper. You MUST use aluminum oxide. I have answered the question to paint a bike a hundred times. Just click on Discover and type in the words paint a bike without quotes. Theres your answer.
