Hi-Bond 2-Part Urethane Pour Foam

Measure equal parts A and B by volume, mix hard for about 20 to 30 seconds, then pour into a dry, contained cavity and let it rise. It foams in seconds and cures rigid and closed-cell, so it resists water and adds flotation. Work between about 75°F and 80°F for a full rise, fill deep cavities in layers, and pour only as much as you can mix in one batch.

Density is the cured weight per cubic foot: higher density is stronger but expands less per kit. 2 lb is for flotation in pontoons, under-deck and bilge voids. 4 lb carries load under decks and around tanks. 8 lb and 16 lb cure dense enough to carve and shape for backing blocks and high-strength fills.

In a free rise at 80°F, 2 lb foam expands about 30 times its liquid volume, 4 lb about 15 to 18 times, 8 lb about 8 times and 16 lb about 4 times. By kit, the 2 quart kit fills about 2 cubic feet of 2 lb foam, 1 of 4 lb, 1/2 of 8 lb or 1/4 of 16 lb, and the 2 gallon kit fills four times that. Cold cuts the rise, to about half at 40 to 50°F.