You know that clearcoat usually has a UV protecting additive put in it to protect teh carbon.
Yes but:
The clearcoat with UV block, blocks 50-95% of the UV depending on the paint. Good grade marine linear polyurethane blocks ~99%. The UV block agent for paint is more durable. For example IMRON uses nickel.
The UV that passes through clearcoat breaks down the paint mast interface which causes the clearcoat to peal.
The paint lasts a lot longer. One of my Marstrom masts is clearcoat with a yellow strip. The clearcoat needs to be replaced again and the yellow paint looks new. This time I am painting the whole mast white.
