Pur Black is a closed-cell, moisture-curing black polyurethane foam. Pur Black is a professional system to fill and seal voids. Pur Black is not ultraviolet resistant. It will become brittle if exposed to direct sunlight. Apply a coat of paint to the exposed foam and the foam will not breakdown. Pur Black can be used to fill all size voids. It can stop the passage of water, small animals, insects, sound, radon, and air. When filling large voids, use a layering technique of foaming and misting moisture on the foam. Pur Black is tack free in 10 minutes, cuttable in 30 minutes, and fully cured in under two hours. Cured Pur Black is resistant to solvent and age hardening. Pur Black can be applied using our pistol grip application gun.