F Seal 181 Duct Sealant With Fiber Reinforced Water Based Formula For Leak Proof HVAC Ducts, 1 Gallon Gray, Indoor Outdoor Use, UL 181 A M And B M Certified For Metal, Fiberglass, And Flexible Ductwork, Made In USA

F-Seal 181 Duct Sealant for leak-free HVAC systems
✔️ Fiber-reinforced, UL 181 A-M/B-M, indoor/outdoor, fast-dry

F-Seal 181 is a premium fiber-reinforced water-based duct sealant designed to seal HVAC joints across metal, fiberglass, and flexible ducts. This 1 gallon gray formulation is ideal for indoor and outdoor installations, delivering durable, leak-proof performance in both residential and commercial systems.

✅ UL 181 A-M & B-M certified for metal, fiberglass, and flexible ducts
✅ Fiber-reinforced, water-based formula delivers leak-proof seals
✅ Indoor/outdoor durability resists mold, mildew, and UV exposure
✅ Fast-drying, low VOC; paintable after full cure; 1 gallon gray, USA-made

💡 What is duct sealant used for in HVAC systems and why choose this fiber-reinforced option?

This sealant seals joints to prevent leaks and improve energy efficiency in HVAC ducts. - Handy for metal, fiberglass, and flexible ducts - UL 181 A-M/B-M certified and SMACNA-compliant - Fast-drying, low VOC for safer indoor use - Paintable after cure and suitable for long-term installations