I have to do some structural glass repair on the hull edges - where the top piece meets the hull, and need to reconstruct some missing (dry and cracked - sort of crumbled) fiberglass. Since the boat was laid up with polyester resin, wouldn't it make sense to use that for the repair, rather than epoxy?

I was thinking that Bondo product with the chopped glass fibers mixed in. It needs to be tough because the part I'm repairing supports the trampoline.

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Hobie 16
Hobie 18
G-Cat 5.7
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Post some pictures of the areas you need to repair. Most likely you will need to use a polyester resin with woven and non woven matting. The bondo with chopped glass included makes the repair itself strong but the weak point is where the repair is bonded back to the rest of the hull.