ATTENTION CUSTOMERS: The global pandemic has been putting huge strains on the raw material supply chain for critical construction products. The limited supply of raw materials in the global supply chain has caused dramatic increases in costs for key elements and raw materials and is resulting in more delays with extended lead times. Most manufactures have already implemented “force majeure” and placed additional surcharges to secure their raw materials. Conspec will strive to fill everyone’s orders as much as we can in a timely manner, however with the supply chain broken, and only receiving partial inventory from manufactures with increased demands the shortages are out of our control. We apologize for the inconvenience, but Conspec will do the best that we can to fill your orders in a timely manner. Thank you for your patience and we sincerely appreciate your business in these challenging times.
Sale! BOSS 333 Triple Expanding Foam
BOSS ProductsBOSS 333 Triple Expanding Foam applicationsBOSS 333 Triple Expanding Foam


Conspec Family Business BadgeConspec Warranty BadgeTriple Expanding Foam, Ready to use 12-oz Straw Can

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BOSS – 333 Triple Expanding Foam

BOSS – 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. Meets CA-25-4 and is UL tested to meet ASTME-72.

• Ready to use 12-oz Straw Can
• Easy-to-use, multi-purpose urethane foam
• Triple Expanding, it expands three times its original volume!
• Adheres to all building materials except Teflon, silicone and polyethylene
• Weatherproofs against wind and moisture
• Seals by expanding into gaps, cracks and crevices
• Uses include insulating, sealing and filling gaps around pipes, plumbing fixtures, ductwork and foundations
• UL Classified Tested to ASTM E-84
• Complies with EPA Method 24 and California Air Resource Board Method 310



To view the most recent Technical Data Sheet, please click here.

Weight 16 oz
Dimensions 2.5 x 2.5 x 8 in
Product Size

12-oz Straw Can