17 October 2012
Despite perfect weather for firing this was not our finest hour, or rather 44 hours. I am inclined to put its failings down to wet wood. We had a ton or so of 60cm long split logs nice and dry in the garage and 4 bundles of offcuts ordered of which only 2 had been delivered. Despite being under tarpaulins the seemingly continuous rain of the summer had left the wood at 30% moisture content (according to Rob's moisture meter gizmo) and the final 2 bundles delivered the day before firing were wetter than the driftwood I pick up on the beech at home.
The lovely Will arrived on Sunday to chainsaw up the bundles and agreed to return on Monday to deal with the second lot. Size matters when it comes to chainsaws, I only wish we'd found Will for the last two marathons of sawing - we were knackered then before lighting the first match. This time we were knackered from the continual rearrangement of wood on and around the kiln as we tried to dry it out. These bundles were of very small bits, far too small for the later stages of firing, and no time to sort it either. Not a perfect arrangement but better than no kiln at all!
Sunday we chopped and stacked wood, straightened the chimney with longer angle iron and brackets and threaded bar top and bottom, and set up tables and the wee pop up marquee which extends the shelter in front of the kiln. Monday was loading day although some precious time was spent on wood. It's a long slow process and so important. I'm not sure we'll ever make the best of it. We each have our own preferences for wadding, dry/sticky, white/flashing, course/fine, and many of the wads fall off by the time the piece reaches the person doing the packing crouched in the bowels of the kiln. More research needed on this. I like a fireclay/course sawdust mixture which flashes nicely and sticks well to the pots, but it also sticks to hands which is not appreciated by porcelain.
By the time the light was fading it had already been a long day and there was still dinner to make and the door to brick up and some clamming of holes to do. It was a tighter pack this time. More shelves, lots more pots, one more firer (5 of us). We had put the gas burner on through the damper at the base of the chimney for a few hours earlier, which was a good move as it dried and warmed up the chimney to improve the draft. It gets very wet sitting through 6 months of Cumbrian weather between firings.
Overnight on gas into the firebox took the temperature to 100? Then we lit a small fire in the grate at 10am and so began the rota of 4 hour shifts, 6 hours off for the next 45 hours.
30 July 2010
For anyone interested here's the firing log for the anagama firing last week
Anagama Firing with Shozo Michikawa at Higham Hall
19th - 22nd July 2010
9.30am Monday. Light fire in ash pit, smokey,
1 10.30am flames being drawn up into kiln, place some wood into
fire box but continue stoking in ash pit.
2 11.30 some smoke from chimney, strong flames in fire mouth, cease
stoking in ash pit. Mix of pine and hardwood
3 12.30pm 490°C Pyrometer now working! Rake out ashes, reduce mouth
of ash pit to increase draft.
4 13.30pm 600℃ Raining
8 17.30 880℃ Still raining
9 18.30 970℃ Breeze blowing directly into the fire box
10 19.3 960°C Everyone present for the first reduction - lots of wood into the
kiln and then close the door over the fire mouth to decrease
oxygen in the kiln. Lots of smoke and dark red horns of flame
from the spy holes over the ware chamber.
11 20.30 990℃ Bit of a party going
13 22.30 1000°C Darkness falls, stoking mostly pine, some hardwood
23.55 1020℃
15 00.30 1005℃ Drop in temp after big stoke
16 1.30am 1040℃ Tuesday, first chimney flame visible.
17 2.30am 1050℃ Much quieter now
18 3.30 1065℃
19 4.30 1080℃
20 5.30 1090℃
22 7.30 1100℃
24 9.30 1120℃
30 15.30 1130℃
33 18.30 1120℃ Sushi interlude
34 19.30 1140℃
38 23.30 1140℃ Pizza. Stoking little and often
39 00.30 1160℃ Wednesday
41 02.30 1160℃ Deep roaring in body of kiln, good chimney flame
42 03.30 1160℃ Running low on wood, heavy stoking to maximize reduction
04.00 Last massive stoke
04.15 Final stoke, one piece of wood each, close dampers fully, clam
up ash pit.
43 04.30 End of firing, daylight.
