Well, I decided to go ahead and build a fire in the firebox to harden up the clay.

Unfortunately, there are just too many impurities in the clay. I still need to process it quite a bit more before it will not break as it dries.

I also need to find some sort of fiber that I can mix into the clay to strengthen it so that it won’t break when it dries.

The part that broke is the cross beam that holds up the base layer to the kiln above the firebox. It is an elongated section of clay and so tends to break as I shape it.