The small kiln has not been fired for a long time and is very damp. After having packed it, Svend preheated it with hard wood for a week, bringing the heat between 70 to 120C.
The crew was Svend, Charlie Collier who works at Wichford Pottery in Oxfordshire and Brigitte. Maddie Carragher of Kigbeare Studio and earthenware potter, Jennie Hale also came to help on the Friday together on the same shift.
Brigitte arrived Thursday afternoon before the firing proper had started; she had brought some glaze tests to sneak in this firing and some pots for the next firing. Svend has kindly given his regular crew members, the lovely Deborah Mitchell and Brigitte, some space in his next firing. While Brigitte was getting her glazes ready, Svend got some shards from his reject pile outside his pottery and dried them on his Raeburn. When the shards were dry, they glazed and marked them and Svend found spaces in-between pots on shelves near the spy holes. Brigitte’s glazes are celadons, a tenmoku and some ash glazes. Svend then put the gas on very low for the night so the kiln would continue drying and preheating.
The firing started at 6am on Friday with Brigitte. The temperature was to gently climb at 75C per hour and the wood used was softwood. Svend took over at 10am until 2pm when Charlie arrived. The next shift was run by Maddie and Jennie : by the time they had arrived, Svend had brought the temperature to 900C and he started the reduction shortly after that. From about 900C at 18:00, it took 8 hours to reach 1100C. From this point, we soaked the kiln between 1140C and 1170C until Monday morning, with a regular shift pattern of 4 hours on – 8 hours off between Charlie, Svend and Brigitte.
Svend had added 18in to the chimney and this increased the draught. This meant that the temperature wanted to climb faster so we had to play with the dampers more than usual.
The main damper was used until the Saturday afternoon then Svend changed over to the passives at 2pm on Saturday to stop the black smoke. The passives were responding really well when we needed to tweak them to manage the reduction and the temperature.
Sunday was uneventful. The schedule was 3 or 4 sticks at the top and at every 3rd or 4th stoke (sometimes we forget to count), 6 sticks in the bottom to keep the ember bed even.
Monday morning at 6am, the scenario was the same but the temperature was hovering around 1204 indicating that it wanted to climb and get it over with. Svend went for his swim after his night shift, but he was soon back because he had forgotten that the pool is closed on a bank holiday. He decided we would finish when he had a rest and had breakfast.
The finish started very well. Charlie came on as well and from around 8:30am we were following the same pattern of 3 to 4 sticks at the top followed by 6 for the ember bed. We reached 1280 at the front and we started the side stoking to get the cones at the sides down. Unfortunately, we should have gone higher at the front before side stoking; we lost the momentum and we had to go back to the beginning. The cones at the sides just would not go down. Charlie and Brigitte went for a rest and Svend stayed by the kiln to figure out what to do. When Charlie and Brigitte came back after 30mins, they restarted the same schedule that had been taking place at 6am. Eventually, we got the cones down, but it was very difficult, very hot and exhausting. We finished at 15:30 hoping for the best.
The wood used
Two kinds of wood were used in this firing. Hardwood because it keeps an even and constant heat: beech, also used to heat Svend’s house, cherry and maple that came from Bjorn, Svend’s son, who had been carving his wooden spoons with it.
And Softwood because it is good for getting a steady temperature rise, used during heat work and until finish: we used Douglas fir in this case.
Svend has a supply of poplar that will be used when he fires the big pots in the big kiln. The plan is to fire the big kiln with only big pots and the theory is that the poplar produces beautiful ashing.
The wood stacks
The wood is stacked by Svend and arranged around the kiln for easy access and according to what we need during firings. Svend often rearranges or moves the stacks before firings so that the older wood gets used sooner.
The bigger logs get split into four and are stacked to the front of the kiln; they are used during heat work and finishing of the front. The thinner logs are separated and stacked at the sides for us to side stoke during finish.
Svend moving the pyrometer from the front of the kiln to the back.
Svend comments over this firing
When I pack a kiln I often find that I am trying to avoid the mistakes of the last firing. The front of the last firing was slightly underfired so this time I used a tenmoku that reacts well with fly ash but melts at a slightly lower temperature.However, when the firing was almost over I could see that it was going to be slightly underfired again so we went back to the front and made sure that cone 12 was completely over across the front and at the sides of the front row of shelves and then got cone 11 down everywhere else with cone 12 moving. This time the front was overfired with heavilly ashed glazes pouring off the pots and onto the shelves.Had I used a harder Iron glaze the results would have been much better. But with overfiring you often get spectacular colours and we got some of those too The rest of the kiln was very good.
We were lucky to have Bjorn around one day. He is a wonderful cook and he treated us to one his delicious curries.