The top coat of varnish may need renewing every 6 weeks or only once a year, depending on conditions in your area. Lightly sand the surface, dust it with a tack cloth, and apply a thin coat of varnish.
When varnish cracks or peels, or the wood beneath gets discolored, it’s time to strip it to bare wood. Use a chemical stripper and bronze wool, then fine sandpaper. Revarnish on a dry, windless day in a place that is out of the direct sun. First wipe surfaces with a tack cloth. Use a foam brush and exterior varnish containing an ultraviolet filter. Apply at least three thin coats. Fiberglass surfaces Fiberglass has a factory-applied exterior finish called gel coat. Its life can be lengthened with auto polish. Nicks and scratches can be repaired with touch-up kits, but recoating of the entire surface should be done by a fiberglass shop or by a boatyard.