System Three SB-112 surfboard resin compatibility question

[Ake G]

This is a ding repair question.

Am in the process of repairing some dings on one of my epoxy boards and using SB-112/ microballoon fills and was wondering if I could use the same epoxy and same materials to fix the dings in my glass surfboard while I'm at it.

SB-112 is supposedly compatible with polyester resins, so do I do the fills w/SB-112 and then do the glass finish coats over those w/polyester resin? Or, can I just do the glass over finish coats with SB-112 epoxy?

[Absolutetrip]

Yes use your epoxy. Epoxy sticks to polyester far better than polyester sticks to anything. I would do all epoxy on your repair as well as the finish coat with epoxy. Polyester over epoxy tends to have issues and will peel off.

[boardlady]

besides being a good structural Epoxy and fairly resistant to UV degradation, sb112 is one of the few that can safely be topcoated with Polyester if you want that glossy finish. Most other Epoxies are softened by the Styrene in Polyester, and while things may look cured on the surface, they float on a gooey interface.