Does anyone know what solvent to use to thin touch up paint? Also, I'm looking for tips on improving my results: I have two spots of bubbling paint on my cars roof. One is next to the antenna mount the other touches the windshield. What I did in other areas is remove loose paint, treat with "rust not" prime, paint, and clearcoat using the duplicolor kit and subaru touch up paint. It does not look great when I do this (this is with no sanding or putty) and these last two spots are more noticeable. I was thinking I would use putty. Sand, and thin the paint for a smoother final result.