Determine Resin Type Used in Old Repair

[tubbyama]

Q1: how can the type of resin used to make an old repair to a MONTAUK hull be distinguished as either polyester gel coat resin or epoxy resin?

BACKSTORY I plan on applying [polyester gel coat resin to the] entire [hull of my] MONTAUK. I see some old repairs that do not quite match [the appearance of the surrounding area] on the [hull] bottom.

I would rather not spray [polyester gel coat resin] directly on a MarinrTex or epoxy repair.

[jimh]

A possible method to infer which type of resin was used to make an old repair could be by assessing the hardness of the resin, assuming the resin was not mixed with fillers. Epoxy is typically harder than polyester gel coat resin.

As for being hesitant to apply polyester gel coat resin over epoxy resin, there will not be a problem as long as the prior epoxy repair is completely cured—which it surely must be by now—and all amine blush residue has been removed with detergent and water.

[tubbyama]

Thank you.