Leading up to the firing
Winter is Svend’s least favourite season: the shorter days combined with the gloomy weather put him in a sombre mood and he finds it hard to start making again after his winter firing. Once the sun starts shining though, and once his favourite flowers, e.g. primroses and blue-bells, start dotting the Devon hedges, he finds his rhythm again and set to work.
The year began with a delivery of wood, followed by the back-breaking work of wood splitting and stacking, and moving the wood that needs to dry off to a sheltered place. This usually means rearranging the wood stacks around the kilns. There is indeed more to wood-firing than sitting by the kiln and chucking a few logs in from time to time. Without the hard work of wood preparation, there can be no firing even if there are enough pots ready for the kiln.
Wood stack at the beginning of the firing
It is also getting more difficult to source good suppliers who will deliver at a reasonable price. Svend used to get off-cuts from his local sawmills but both have closed. It has taken many years to persuade the local forester to take him seriously enough to sell him wood in the round in large quantities. He probably thought that Svend was some dreamy hippy and best avoided from a business point of view.
Wood stack on the second day of the firing.
Svend made the usual tableware pots: various sizes jugs, different types of bowls. storage jars etc… He also put in lots of bowls thrown off the hump and some biggish jars. The big pots that are standing on the bench by the pottery window will be fired in the big kiln later this year. As well as unglazed pots, there is a number a celadon and kaki glazed ware, with two celadon large jars placed in the fire-box for ashing.
A few of the pots that went into this firing.
Making began slowly and took about two months, glazing a week and packing about three days.
The general course of the firing
Svend started with gas until 300C then both gas and wood were used until the alpha beta conversion. Wood only was used until the end of the firing. During the day on Friday, the crew consisted of Svend and Brigitte ; they were doing six hour-shifts each. On Friday night, Maddie Carracher of Kigbeare Studios and Darren Ellis of Maze Hill Pottery worked together on the 10pm to 2am shift, after which Brigitte took over again for four hours. On Saturday, Svend and Brigitte worked six hour-shifts again until 6pm when Deborah Mitchell of Zanzig in Cornwall arrived for the week end. From then on, the team, (Svend, Deborah and Brigitte) worked four hour-shifts each until Sunday evening.
Svend had intended the firing to last 48 hours, but it ended up lasting 60 due to problems at the end of the firing.
The bulk of the firing went without problems, except for an unexplained sudden drop in temperature at 5am on Sunday morning on Brigitte’s shift. The only noticeable difference was in the weather: the temperature seemed to have dropped just when there was a sudden gust of wind that lasted well past her shift. From 1180C, it dropped to 1120C and it was impossible to bring it back up despite using the usual tricks of playing with the passive dampers and trying different amounts of wood.
Deborah took over from Brigitte at 6am, followed by Svend at 10am. Brigitte then got up at 11am to join them for the finishing stage but Svend wanted to get more heat to the front of the kiln before the finish started properly so he sent the ” ladies” (he calls us his Svenettes) back to the house for a rest until 2pm.
The fire chart.
Svend gives his own account of what happened on Sunday from 2pm onwards.
This has been one of the strangest and worst firings I have ever had. I have fallen off this bike so many times, but this time I really have scraped my elbows and knees. However, I am still intrigued enough to want to get back on. One way or another, I will learn how to ride this damned contraption.They say that you never learn by getting things right. I am wondering just how many more big basic mistakes I have to make before I begin to reap the rewards of all this experience?I have, afterall, been at it for 45 years.
This was the third firing of my small kiln.In it I was venturing out into the world of simple celadons. I am not methodical and that is one of the main reasons for getting things wrong in a big way.However, this time a good friend let me test fire all my new glazes in her gas fired kiln. They all worked and so I chose the four that I liked best and together with my three regular glazes, glazed all my pots and spread the different glazes equally through out the kiln. Unusually for me, everything was biscuit fired.
The kiln packing was my standard pack and went well. Because the kiln was damp I pre-heated with gas for 24 hours until there had been no steam at the chimney for several hours.The temperature was 300. Thereafter the firing followed a slightly faster firing curve than I normally do ( after all, everything was biscuited ). At a fairly early stage I decided to make it a 48 hour firing ( as if I have the power to decide these things ! ).
24 hours took the kiln to cone 9 beginning.The next 26 hours of deliberate flat lining took the kiln slowly to cone 10 and 11 over in the middle of the front. 3 hours later 12 was over and 11 over at the sides of the front and 9 and 10 over at the 2nd side stoke with 11 beginning. Everything was going according to plan apart from a few unexplained dips in the curve a little earlier on. Now it was come-uppance time and the kiln just lost momentum.Several hours later the kiln was still stalled and so I decided to go back to the front and start all over again.
The temperature climbed quickly on the pyro and when I could see that cone 12 was totally flat all over the front , side stoked for about half an hour and then stopped. At this point I took out some rings and could see that all the celadons looked fine. One was even exciting. Now I made my big mistake. Instead of cooling in oxidation down to 1000 , I clammed the kiln up with a big ember bed still burning. A small blue triangular flame at the blow hole showed that it was reducing. Usually this works well, but not this time.
On opening the kiln I found , as I had half expected, that the front, having been at high temperature for far too long, was very over fired. The next thing that I discovered was that all my new celadons had gone matt and crystalline and were a yellowish opaque off white. Basically I had destroyed the firing by cooling in reduction. My usual celadon does not seem to mind. All my new ones hated it. Oh well, shit happens.