It was with great excitement (and a little trepidation) that I travelled to Uclan this morning. I was anxious to see how my pebble bowls had done in their bisque firing.
Very disappointed to find that both large bowls had exploded and shattered in the kiln. On close inspection, the base of one revealed a possible air pocket. A huge risk of layering clay is that air pockets can build up. In normal circumstances the clay would have been wedged and pummelled with some force to allow the air to escape. However, because the clay had been coloured and I wanted to keep the strata effect, perhaps I hadn't been tough enough with the layering ( even though I have bruises!)
A lovely email from Michaela with some sound advice and recommendation for the next step.
"I've had a thought about your pieces and think your large pebble bowls need more support both during drying and firing. Why not make a quick rough clay ring from reclaim clay which your bowls can sit in for drying and firing? You then just throw the ring away after firing. I think the weight of the clay is too much for the one pressure point it is sitting on when the bottom is curved. In a ring it would sit like in a cradle and the weight of the clay is redistributed that way."
Thank you Michaela.
Below is the remains of the base after high firing. It shows the fabulous strata which 'could' have been part of a really spectacular pebble bowl.
Back to the drawing board...with only 3 weeks to go!