My only experience with fiberglass is small repair on some sailboats where it was to be painted later, and clarity wasn't an issue. What I am wondering is what does it look like after sanding the fiberglass to remove bumps or high spots? Even with a fine grit, is it still crystal clear? Do you have to paint on some epoxy after sanding to make it clear again? Or does the varnish fill any fine scratches to make it clear?