I'm saying clear it.Scrub it real good with the BKF to remove rust, then if you have a friend at a body shop, have him spray a coat of clear on it. Our painters are always mixing to much clear and the leftovers normally will always do a sign. Besides, if you don't like the clear, it is easily removed. I have done one myself and I am very happy. As for sanding it, I see no need for it. IMHO.