Several days back I wrote of my recent kiln disasters with my holey bowls and the addition of the concepts of shivering and dunting to my ever-expanding vocabulary of ceramics. Well, lo and behold I turned up to the art studio a few days later only to be confronted by yet more disappointment.
This time it was not hand made art bowls, but two simpler wheel-thrown bowls that had succumbed to a similar fate. Again, luckily no other art work was impacted (literally) so it was only my work that was ruined.
So, as it doesn’t seem to be the design of the works that is causing the issue, we are left with the conclusion that it’s the choice of clay I have been using. I have recently switched to Hugo gray clay, one that is very suited for sculpting and handbuilding, since we had over 50 lbs of it left over from other sculpting activities. This clay is said to throw well and be adaptable to all craft glazes up to cone 7 for vitrification, so I didn’t think there would be any problems and I cannot understand why I am having so much trouble with it.
Not surprisingly, the Studio Director no longer wants to fire this to high fire, for fear of damaging the kiln, so we have agreed that we will bisque fire what I have and I will then use low fire stroking coats to do a second low fire (cone 06) to get some color onto the pieces.
If anyone has any ideas as to why this may be happening, please feel free to add a comment.