Firing 23

No wonder I was twitchy, it’s 5 months since the last firing. According to the weather forecasts I shouldn’t have been able to do this one either. However a kick into action from the angels earlier in the week in and I managed to coordinate being ready for the only decent day we have had in weeks (months to be honest, though it feels like years, but this is NOT a ‘moan-about-the-weather’ post)

I’ve been putting myself under pressure to make pots ready for a firing here and for the Higham Anagama in April. The calendar is filling up with Potfests and galleries wanting work. I knew I would have to be ready to fire at short notice if the weather looked promising. It takes a day to pack the kiln, carrying glazed pots from the studio, wadding them, placing them, taking them out again, rearranging them to squeeze another one in or to get a better flow of flame around them. Too much wind and rain on this day makes it very unpleasant to pack. So really I like two good days in a row.

This time I had a potter friend from Aberdeen (Sjarifah Roberts) to help carry and pass stuff which was a great help although she couldn’t stay for the firing. She’s wanting to build a kiln herself and it’s SO much easier to understand all the variables of kiln design when you are actually standing in front of one. The books are great but nothing beats getting involved with someone else's build or firing.

The usual start at 5am to put the gas on low. I had given the kiln 4 hours of drying the evening before, even so it continued to steam like a sauna for the entire firing. I was concerned that the wood might be damp too from months of high humidity.
The morning was dry but overcast with a breeze from the west which continued for most of the day with a few showers and quite a bit of sunshine.
Firing followed it’s usual pattern at first although I kept the gas going for an extra 2 hours after introducing the first wood at 8am.
Normally I get reduction happening at 900ºc after 8 hours. This time it was at 1000ºC, perhaps the wind in the west was increasing the draft, it certainly takes the smoke away from the shed  very effectively. Generally it was a more oxidising firing with a low bed of embers which I only had to scrape out once.

Another potter friend (Robyn McGraw) arrived at 1pm and helped with the stoking for a few hours while I drove around the village looking for the dog who isn’t impressed with the kiln and prefers to hunt for bird food scraps that the neighbours leave out (and he steals my wood). The first soda went in after 10 hours at about 1150ºC. then two more lots during the next hour. About ? g in total.
Robin had to leave at 4pm so missed 1200ºC at which point there was an almighty downpour and i lost temperature which stalled the kiln at about 1160º. It was a long slow climb back to 1220, achieved by closing the shed doors and feeding one small piece of wood at a time for for the next 3 hours. Because the kiln is built mostly of HTI bricks it has a low mass and doesn’t hold its temperature for long. It was raining more by now and blowing from the south west into the fire box. Exhausting but satisfying finally to achieve 1220º for a while and see cone 9 going down.

Pots from firing 10

Detail of standing stone

small pebbles and standing stone, dia 10cm

cutlery drainer and dish, ht 11cm

textured dish, dia 31cm

selection of mugs, ht 10cm

Firing 10

3 May 2010

Up at 5 am to put the gas on. I chose the right day to fire today. It's already daylight and the birds are just beginning to sing. No clouds on the horizon. Back to bed for a couple more hours.

2 7am 97°C Turn gas up. Still sunny but gusting from the north

7.30 157°C Large log in with the gas on it

3 8am 185°C Wood slow to catch fire

8.30 212°C Removed a half course of chimney bricks to allow wind to increase draft. Gas off

4 9am 440°C Oops! now romping away. Removed damper brick

9.30 532°C Slowing down, damper closed

5 10am 540°C

6 11am 690°C

7 12 noon 818°C First heavy smoke

8 1pm 1024°C First sign of reduction flame in chimney

9 2pm 1115°C

2.30 1150°C First soda into firebox

10 3pm 1169°C Second soda in

3.30 1190°C Third soda in. Cone 5 down

11 4pm 1208°C Cone 8 bending

4.30 1190°C Lots of fluctuation, 1224°C tops

12 5pm 1213°C Cone 8 down

5.30 1221°C Maggie arrives to view firing

13 6pm 1199°C Firing down whilst beginning to clam up the kiln.

6.15 1175°C Beer at 5°C

this firing included a cone 9 test glaze on the top shelf from Elizabeth Westman so I was trying to soak the kiln at top temperature to see if I could get the test to melt well. All cone 8’s throughout the kiln went down and there was a good melt of soda with some carbon trapping.

Image shows chimney brick beginning to sag out of line. Probably due to the bed of sand we used to even out the bumpy concrete. Rebuild will be required soon I think. You can just glimpse the test glaze at the back - black shiny, green where thin, good melt. Will get cone 9s for next firing.

Can't wait.