Use for stoves and fireplaces. Used to re-point mortar joints in a firebox. Meets ASTM E136-79 flammability test.
Clear all dirt, dust and debris from the area to be repaired. Lightly dampen the surface area with water. Cut nozzle for desired bead size at a 45° angle.
Using a caulking gun, apply by pushing mortar ahead of nozzle. Fill the crack or hole and smooth with a trowel. Clean up spills immediately after use. Air dry for 24 hours then heat gradually when first starting fire.
Not for exterior use.