James L Bowen on fri 10 mar 00
My limited understanding of this is that the calcium in the clay loses water=
the firing and does not fuse with the other materials in the clay. Upon =
it starts to rehydrate and over time as it adds water it will swell enough =
cause a pop off. So the solution is to use a clay body that not will cause
this. Contact your supplier. I have been told that California fire clays are
more likely to be a problem than Missouri fire clay.