If clear coat over Gel Coat, then scrape off the loose clear coat and sand the remaining attached clear coat to a dull finish using 400 or 600 grit sandpaper.
1. If you use SprayMax 2K rattle can you will get a new shine (after some color sanding and buffing) but have some ridges where the old clear coat meets the peeled clear coat areas. High up off the ground so not so terrible to look at. This lasted about 2+ years for me.
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2. Spray a primer, spray a base coat, then clear coat. This has worked for the brow of my rig for 11 years since it was done.
If the current clear coat covers a base coat instead of Gel Coat, then sand the old clear coat off, reapply the base coat, and spray a clear coat.
New Clear Coat over old Base Coat will not be durable according to my research. My two part instructions require that the Clear Coat be sprayed within 24 hours of applying the base coat. Base Coat applied within 36 hours of the Primer application.