PU Foam Spray in coimbatore Boss 333 polyurethane foam spray is a ready-to-use, multi-purpose, polyurethane foam spray that expands to three times its original volume on contact with air. The expanding action fills holes, cracks and gaps more completely than standard caulks. Boss 333 has excellent insulting properties and adhesion to virtually all building materials.PU Foam Spray in coimbatore. polyurethane foam spray, PU foam spray