Is polyester resin UV stable? Annette DiOrio May 05, 2021 19:07 Updated Polyester resin is relatively UV stable and can remain exposed to sunlight for a long period of time without yellowing or degradation. Gelcoat is an example of a UV-stable polyester resin. Related articles Can I apply TotalBoat Gelcoat to a fiberglass swimming pool? Does TotalBoat Gelcoat require thinning? How soon can I apply TotalBoat Gelcoat after applying TotalBoat 2-Part Epoxy Primer? Do TotalBoat epoxy products have any UV protection? How long do I need to wait for gelcoat to cure before I can sand it? Comments 0 comments Please sign in to leave a comment.