Large piece exploding during the glaze firing.

[Sinead Pollard]

Hi all,

I have recently acquired a large Nabertherm kiln in order to make large peices that have always fired well at my previous shared studio.  However, i have recently glaze fired a large piece built in three parts which cam out of the kiln in pieces. It looked as though it had twisted and torn apart. The clay body was a light stoneware covered in a bought clear glaze and was fired according with the glaze instructions. I did notice that the kiln, on it pre-set glaze programme, seemed to heat up very quickly. Does anyone think that if i slowed down the heading ramp that it might have a better chance of surviving? I appreciate this is difficult to diagnose but any ideas would be most welcome!

[Pres]

I believe that your analysis is spot on. Over the years I have fired several student pots that were what I would consider oversized. At the same time these pieces were student work and so not as well constructed as a professional or good hobbyist. My  firings in the day were controlled by a setter, and for bisque and glaze I erred on the side of high caution, turning up the kiln slowly watching the climb and making certain to let the kiln cool naturally. It really helps. My ramp up took my entire teaching day until around 4-5pm when I would turn all switches to high.

Hope this help.

 

best,

Pres

[neilestrick]

@Sinead Pollard How thick is the piece? If you post some pictures that will help diagnose the cause.