333 Polyurethane Expanding Foam

333 is a ready-to-use, multi-purpose, polyurethane foam 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 insulating properties and superb adhesion to virtually all building materials.
Not a flange sealing product, but talk of sealing products and can’t ignore this construction sealer. PSC 333 is a ready-to-use, multi-purpose, polyurethane foam 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. PSC 333 has excellent insulating properties and superb adhesion to virtually all building materials. Used for sealing partition walls with ceilings; through penetrations around cables and pipes; seams between chimneys, roof protection, roof panels and wall panels.

UL Classified, Tested to ASTM E-8

FEATURES
  • Meets CA-25-4
  • UL Classified, Tested to ASTM E-84
  • Triple Expanding
  • Weatherproofs against wind and moisture
  • Fills gaps, cracks and holes
  • Seals out insects and pests
  • Can be sanded, painted and stained
  • Complies with EPA Method 24 and California
  • Air Resource Board Method 310
  • VOC Compliant
USES
  • Air sealing
  • Partition walls with ceilings
  • Through penetrations around cables and pipes
  • Seams between chimneys, roof protection, roof panels and wall panels
HOW TO USE

Shake can before and during use. Surfaces must be clean and free of grease and oil. Can must be held UPSIDE DOWN during application. Insert straw into void and depress the trigger. Fill void 50% full to allow for expansion. For best results, use in temperatures between 60°F to 90°F and spray mist into cavity prior to applying foam