Like Spelljammer, I'm more interested in reusing the uncured resin than the salt water. After all, I live across the street from the Pacific Ocean. I would filter the water I collect to minimize any possible contamination but if the resin isn't water soluble I don't think it should be much of a problem; certainly worth a try.

Has anyone tried to recover extra resin for reuse? Does it cure on exposure to air as well as UV light?