Using clay for backfill.

[Chris inPA]

I have a cousin that's potter by trade. He's got a considerable amount of potters clay that's no longer good for his use. It's either got some type of dirt or small stones in the matrix. So, he can't throw it on the wheel. Could I use this to back fill between the joints of the firebricks on my dome?

I will be using refractory mortar to hold the bricks in place of course. But to fill all of the voids could I stuff it with this clay? If so, I can save $$$ on the amount of mortar I'm going to use.

[hughjamton]

I'm not an expert but logic tells me you should use it in a homebrew mix, 3 sand 1 Portland cement, 1 hydrated lime and 1 clay.
I would think that would be perfect for your needs.
By itself I imaging it will shrink too much to be useful.