All Gelcoats are WATERPROOF and safe for Use Below the Water Line.
Use for doing a repair (boat, snow mobile, RV, swimming pool, shower, tub, sink, etc) or making a mold are gelcoats are NPG Isophathalic grade.
Used it to paint the inside of a concrete bird bath.
Repair surface cracking white in ground fibreglass pool.
This gelcoat sands easily and buffed out for a perfect finish.
Topcoat finish fibreglass tub repair.
Coat live well fish boxes