Refractory Mortar: Fresh Fireclay and Ground Firebrick Worked with Water

Ure's best lute for joints that must stand the fire is a dough of fresh fireclay and ground firebrick worked with water. Break and grind old firebricks, sieve them, mix with fireclay and water to a stiff mortar, and lay firebricks in it. The picture: our diagram, fireclay and ground brick become the mortar between firebricks.