Sunday 18 November 2018

Pit Firing 2018

Back in September I tried out an alternative firing technique called pit firing. Although I enjoy using my electric kiln, it's fun to try something different now and again. I used to fire using a raku method but my last firing was seven years ago. Since then I moved house and now have a garden with enough space to try some firing experiments. Time to play with fire!

Pit firing (also known as smoke/sawdust/barrel firing) is a low temperature firing technique with origins in ancient methods of firing pots. Traditionally people stacked pots into a pile or pit in the ground, covered them in wood and other combustibles before setting alight. Instead of using glazes, chemicals found in the combustible materials react in the firing to create smoked surface markings. This gives some amazing results which I was keen to try.

Plans for my pit firing experiment started way back in the beginning of the year. I bought some white stoneware clay to use instead of my normal buff stoneware. Smoke markings show up better on a white background. I also decided to throw some rounded forms on the wheel because this allows the flames and smoke to flow over a larger surface area. Rounded shapes also survive better in low temperature firings. This naturally led me to make a batch of pots that were inspired by seed pods - which seemed fitting as I also had to collect lots of natural materials like grasses, seed heads, sawdust and seaweed to add as combustibles.

The pots were all burnished and then bisque fired (fired once) in my 'normal' electric kiln to give them a better chance of surviving the fire. The original plan was to do a pit firing in July but because the weather was extremely hot and dry for weeks (remember?!) it was too dangerous to risk lighting a fire in the garden - it was a tinderbox. So I waited until we'd had enough rain. Come September I'd managed to collect all sorts of additional materials including salt, copper (in various forms) and fruit peelings.

At last I had three days free to attempt a firing. The first day (very warm) was spent 'decorating' the pots. This involved packing a selection of the materials around the pot itself in the hope any chemical reactions will transfer directly onto the surface. Then I wrapped them individually in either aluminium or paper saggers. This took all day to do as I had quite a nice batch of pots and small pieces to decorate. And luckily I chose to do this outside and not in the studio because it proved to be messy. It's also nice to work outside for a change.

The next day I prepared my fire. Instead of a pit (not keen on digging a big hole!) I decided to use a barrel. It works on the same principle. So I sited my barrel and set to packing it. From then on my barrel became a 'kiln' in my head! Packing the kiln was all about reverse thinking - the fire is lit from the top not the bottom, so I have to plan the layers of sawdust, shredded paper, kindling and wood to cover the pots and to allow room for the fire.

After a shaky start (the fire smoked too much at the start and I couldn't get it to flame) at last I managed to get a good flame and fed it for about two hours. Then I closed the lid and stopped up all the gaps. I used a chimney cap on the top and wet clay as bungs. And then right on cue it started pouring with rain! But there was nothing I could do but leave it to smoke overnight.

I had no idea what to expect come morning. I was trying to stay philosophical as I walked up the garden to check on my 'kiln'. It could go either way. I lifted the lid. Warm ashes at the bottom. But also a patch of red. A red pot (you can see it in situ in the photo I took above). I picked it out and wiped off the ash to reveal a gorgeous little pod pot. And lots of others too, one after another. I was absolutely amazed and chuffed to bits at the results. And instantly, completely hooked!

The last phase in these complicated little pots was to polish them all with natural beeswax. In doing so the detail and patterns in the surface really show through. Every side of each pot has so many interesting markings that - depending on where you're looking - it can seem like a completely different pot. The marks themselves bring to mind all sorts of abstract visuals - many of the pots look to me like tiny planets or moons or a miniature cosmos. But I expect everybody will see something different in them.

All my new 'pod' pots are available in my Etsy and Folksy shops. I really enjoyed making these - they are so unique and fun to do. I'm already planning to make more next year!