If you ever get talked into using this product under the waterline when on the slip, be cautious of drying times as it can delay your return to the water.....personally I should have went with west system and micro balloons with fast hardener. Epifill drying times is approx 12 hours at 29 degrees and it sags with large aplacations . My slipping has just been extended to 4 days rather than the normal 3 days.
Depending on the situation you might be better off using Fibremax. Goes off in 20 minutes or so and unlike body filler is actually waterproof. I like epoxy and micro balloons too but it can be a pain to stop the sagging. Fibremax can be faired while its still green like body filler with the right tool.
I've used it and its hardened in 3hrs good enough to sand and paint , on cold days,
just have to add a lot more hardener than recommended.
Not sure what that does to structural integrity of the fill.
