Now you can keep joints and openings airtight with fiber-reinforced Hearthstone Furnace & Stove Cement. The proprietary fiber-enforced formula literally locks openings closed. Tiny fibers in the cement lock together to give this compound a structure integrity that virtually eliminates cracking and crumbling. Its high adhesive quality makes Hearthstone Cement cling to surfaces during application, set-up, and after curing. Its soapstone content minimizes thermal stress. Contains no asbestos. In addition, it cleans up easily with water. Hearthstone Furnace & Stove Cement is water-soluble. A soggy rag or wet paper towel left to soak on any unwanted residue for an hour or so makes subsequent clean up quick and easy.