Wednesday, May 3, 2017
Firing a reconstructed wood fired kiln.
We fired the wood fired kiln this morning. The firing was the first test of the kiln after a major redesign and rebuild of its interior that I began late February this year. Some time in the future I will try to put together a post about the rebuild, because a number of the design ideas were a bit unusual, and were an attempt to solve the problem of making a wood fired kiln that was easy to load and fairly efficient to fire, so that I could cope with it in spite of now having some limitations physically. A few of the ideas might help someone else.
I loaded the kiln a few days ago, and gave enough time to prepare some fire wood and have a bit of a rest before firing day. Yesterday afternoon I lit a small fire in the ash pit of the kiln and kept it going for a couple of hours to dry the kiln out, as it had not been used for two years.
I got up at 5 this morning and, before heading outside to start the firing, joked to Laura that this might be one of those fast firings that gets done by lunch time. the sort that some potters like to boast about, that get to cone 10 in 3.5 hours and only use half a dozen broken pallets as fuel for the entire firing!
I lit the fire at 5.50am, and, to my great surprise, discovered that I had a fast firing kiln, that was economical on wood and easily reached about 1240 degrees Celsius (2264 F) by 10am! At that point I commented to Laura how easy to fire it was, and lost my concentration! I added a bit too much wood, stalled the kiln, and then spent 2 further hours with the temperature rising a little then falling, then rising again. I did finally get somewhere above cone 10 in the hottest part of the kiln, and about cone 8 where things were cooler. In some respects I was very pleased with the 2 hours that the kiln spent chasing peak temperature, as it will have given time for glazes to mature and fly ash to melt and do its magic with the pots... well, I hope so!
The amusing thing was that we did get the kiln fired by lunch time!
The top of the kiln chamber was firing hotter than lower down, and I will make some changes in how I pack the kiln for the next firing to try to even things out. Simple things, such as how far apart the shelves are placed, and how densely they are packed, should make a significant difference with this.
I hope to unpack the kiln on Friday, so will take photos and give an update when we have the work out of the kiln.
Very tired now, so will wrap this up, but really good to have a kiln with actual flames and wood smoke operational again!