TotalBoat Polyester Structural Marine Repair Putty can be used to fill the ground-out area left behind by an osmotic gelcoat blister. However, when possible, an epoxy-based fairing or filling material is recommended.

Polyester Structural Marine Repair Putty does not contain an air-dry agent, so it will cure to a firm, tacky state unless it is deprived of oxygen. It is also not a waterproof repair solution and must be topcoated with either gelcoat or a primer and paint. Gelcoat should only be used as a finish material for repairs above the waterline or on boats that are not stored in the water.

Using an epoxy-based fairing material such as TotalBoat TotalFair Epoxy Fairing Compound provides better adhesion to the substrate and creates a waterproof repair. After curing, TotalFair should be primed or barrier coated, then topcoated as required.