One Component Polyurethane Foam Sealant 750ml PU Foam Spray for Gap Filling and Building Crack Repair Core Product Advantage: This single component expanding polyurethane foam comes in an aerosol can and works straight from the tin. A disposable straw nozzle fits the valve so the user presses and applies without a spray gun, compressor or mixing step. The foam flows into narrow openings and cures into a firm mass that locks the gap shut. Practical Function Design: The foam