cheap fiberglass repair on paddle
We assume you applied 2 coats of fiberglass using epoxy resin. Agreed on comments that this should not be your primary paddle in isolated canyons but if it fails slightly again I'd recommend:
1)sand off old repair
2) use 2-3 layers of very thin fiberglass and a marine specific epoxy like West Systems. Make each layer perpendicular to the last so the tension resistance is in all directions. Make each layer at least 2-3 inches beyond failure as stress = force / area

Use a small roller to roll out excess epoxy out of fiberglass as any surplus simply adds to weight but not strength. Do all layers at same time...doing them separately only allows the epoxy to mechanically bond and not chemically bond.
3) cover the repair as it drys with seran wrap then compress the crap out of both sides of repair like a sandwich using sand in a zip lock bag etc to make a vacuum system of sorts using tie down straps to squeeze the sand in zip lock bag.
4) do cover the dried epoxy repair with a UV barrier like spray paint otherwise it ashes and turns opaque.
If you'll bring it to Boulder I'd be happy to do a repair but again it shouldn't be used on any isolated outings as primary paddle.
Best,
Jeremy Rodgers
Boulder