700 grams of cone 10 clinker slop, (recycled cone 10 clay).
50 grams Alumina Hydrate...
Saw dust... (add and mix in until the slop becomes wedgable, then wedge-it up, divide it, and wrap up the batch for damp box storage.)
This may or may not go unsaid... apply small wads to the bottom of wear by dipping wads lightly in wood glue thinned with a spot of water. This is enough wadding for a very liberal application in (2 to 3) 17 cubic foot kiln loads of work.