Meeco'S Red Devil 10.3 Oz. Gray Ready-to-Use Fireplace Mortar. Pack of 2. Furnace cement and fireplace mortar in a convenient 10.3 oz (ounce) cartridge. Multi-purpose cement for bonding and sealing both masonry and metals with working temperatures up to 2000 F (degrees Fahrenheit). Designed for patching or repairing cracked or chipped firebrick and mortar. For use with firebrick, gasketing, mortar joints, and wood stoves. Effective in resetting and cementing furnaces, stoves, chimney collars, boilers, and duct work. Tube does not include replacement cap.