Firing pottery is the last step of the making process, where all the gestures and decisions and movements and accidents are solidified. No going back, no going sideways, whatever comes out is. Is, just is.
Firing is effectively just heating the pots up, and letting them cool down. There are a few different ways that you can do this, with today the most popular being using electricity (think: high-powered toaster oven), gas, and wood. I use an electric kiln in my studio. My first experience with wood-fired pottery was in October, 2016, and here are some notes from back then:
I’ve met a few potters around where I live, and one of them lead me to a kiln at a place called Atelje Janja Gora, a house-cum-pottery in the hill-lands of central Croatia. It’s run by a husband-and-wife of Branko Šupica and Danijela Pešut who hold occasional workshops and firings. 10 of us got together with our pots and plates and cups and bowls and vases and shape and love, hoped for the best and came out with not-the-worst.
This kiln is an “anagama”, an ancient kiln design (first built some 2000, 3000 years ago) that spread across Korea and Japan and which let them fire with higher temperatures and more consistent results than western potters achieved in the 1500s. It’s essentially a tunnel: the wood is put in the front, it burns through the chamber and melted ash lands on the pots, and then the heat exists through the rear chimney.
This kiln was built in 2013, with help by the Belgian kiln-builder Lou Smedts, and it’s been fired about twice a year since then. The last firing went to a pyrometer reading of 1300c in 12 hours and although cone 11 was down in the front the back barely hit 1100c. Their goal this time was to get up to temperature and hold it till some 50-60 hours elapsed.
My first wood firing ever. My first (since university) cone 10 firing, first (since university) reduction firing.
There were a few surprises along the way, largely due to my misunderstanding. I thought it would be a salt firing, so I read up and glazed up appropriately. Turns out they used 1 kg of salt primarily for sealing up the surfaces, as opposed to inducing effects. And nobody else glazed because they were hoping for major ash accumulation.
It follows that they planned for a 60-ish hour firing to cone 11+. About 22 hours in, about 4 hours after reaching 1300c and some 8 hours after reaching 1200c, we took a peek inside and saw one of the kiln shelves in the front stack bending badly. We sealed the kiln up right then and there: better to not get so much ash than to risk losing the first if not all 3 stacks.
So, it sat and cooled five days. The pyrometer still read 88c on the morning of the opening day. We opened it.
I had lots of issues with my glazes/glazing. All glazes were mixed from recipes using powders purchased from my local pottery supply. I’d never used any of them before. But some of the stuff worked out. Only one piece actually broke and that’s because during stoking it got pushed up against the wall and melted together.