I am restoring an antique car and am at the painting stage. The bare aluminum was pretreated with phosphoric and chromic acid washes followed by five coats of an epoxy primer. I have applied three color coats and sanded between coats. What I had hoped would be the final coat has turned out less than perfect. For the most part The high gloss is ideal but there are two small areas which are dull, I assume due to too thin application. Can I sand these areas and respray them or must I sand and repaint the entire panel ??