This has to be one of the more unpredictable and exciting ways of finishing a piece.
First I make some terra sigillata with white stoneware clay, this is applied to leather hard clay or bone dry clay, buffing with a chamois leather between each application. I have applied it to white stoneware, black and terracotta clays. These I then biscuit fire to 950C to try and keep as much of the sheen as I possibly can.
Using my trusty ‘old’ bin I fill it using sawdust, driftwood, dry seaweed, sea grasses, oxides, predominately copper and salt, these are all layered and sprinkled with an element of design, placing pots carefully, being aware that if they touch each other smoke will be prevented from reaching the clay and also being aware that as the contents burn so the pots will drop down. Next the bin is lit, I alternate from having all the air holes at the bottom open too some or none depending on how smoking or hot I want the bin to get. A firing takes anywhere from 24hrs – 48hrs.
Then come the opening..quite a tentative moment, uncertainty creeps in, will they have survived the firing, what will they look?! To date I have had a few successful pieces, some coming out with beautiful reds, others with deep blacks and layers of greys.
Finally I wash the pieces removing the last remnants of ash and then apply some good quality beeswax to seal and give the final glossy finish I am looking for.