$27.95
Fireplace mortar patches cracked or chipped firebrick and can also be used to fill in missing mortar joints. You can fire it immediately. First burn a low fire to dry fireplace mortar, then heat strongly to cure.The final cure requires 1200 Degrees to strengthen the mortar to firebrick hardness. Can also be used on any wood burning stove as well. 2000 Degree limit. Don’t use mortar outdoors for firebrick repair. Ideal for holes or cracks not wider than 1/8". Fill larger joints in layers. The mortar will dry as hard as firebrick if it is properly cured and will withstand 2000°F! .