The final firing

The final firing of this little kiln that is.
Number 27, 7th July 2012

That was the Wimbledon weekend when Andy Murray finally made it to the final and I realised on Friday that I had to fire on Saturday in order to watch the tennis on Sunday. Only the realisation happened on Friday evening after he won the semi, which I had been watching instead of packing the kiln (keep up there).

If I packed in the morning and fired into the night I would get enough sleep to be awake again in time for the final. That's if the forecast bad weather held off long enough.

Another fairly loose pack. Flat black clay tiles on the bottom shelf 'wadded' on silica sand, two more shelves, large platter on the top shelf. Cones 7, 8, 9, 10.

Midday Saturday, high cloud, gusting from the North and North East, a bit chilly really but DRY and NO midgies.  Lit the gas to get it going. The gas blew out so for the first time I started with wood alone. Usually the kiln has absorbed so much moisture from the humidity that I have to dry it out for at least a couple of hours on gas. However whilst the covers have been going on at Wimbledon and England is doing an impression of Atlantis this corner of The Misty Isle is having a drought.

Five hours later with the pyro reading 993ºC I reckoned it was as good a time as any to let the kiln do a fast fire!
After 7 hours it was at 1158ºC after which it started to slow a little
After 8 hours it was at 1168ºC but touching 1200º so I put the soda in, about 250g
          9 hours               1212ºC  cone 7 bending
         10 hours              1220ºC  cones 8 & 9 softening, getting a good temperature rise with thin pine branches about 2 - 3 inches diameter.

After 10 and 1/2 hours it reached 1251ºC with cone 10 softening. End of firing.  At least 3 hours shorter than normal.

Bed, sleep then sit back and watch Andy lose! But just like woodfiring it's the taking part that counts not just the results.

Firing 14 - refiring most of firing 13

Another 5am start, pitch dark but starry. Gas burner on.
7am   100oC   gas up, weather is still, overcast and damp
9am   310oC   gas still on, damp wood, damp kiln, did not do a warm through yesterday, kiln steaming - low fat pots?
10am  480oC  gas off, hard work to keep this fire going. Am I tired? not really enjoying this
11am  616oC  south west breeze. Now the fire is more beguiling, it becomes a reason in itself to continue. The kiln has ceased steaming
noon   730oC
1pm    878oC   using large slab wood, strong s.w. breeze
1.30   1004oC  reducing for a good half hour
2pm   1024oC 
3pm   1088oC   first soda in. Cold s.w. wind blowing into fire mouth,
3.30pm              closed the big doors for shelter
4pm   1088oC    then at 4.05 up to 1126oC
5pm    1145oC
5.30    1165oC   Andrew stopped by, just to check that the flames were intentional
6pm    1166oC  
6.30    1200oC   cone 7 bending
7pm    1203oC   cone 8 bending, 7 down
7.30    1211oC
7.45    1187oC   cone 9 beginning, cone 8 down
8pm    1215oC
8.15    1220oC   cone 9 down, last big stoke, start clamming up the kiln, a few slivers of wood added during this.
9.15    1078oC

I didn't make a note of when I put the fire mouth door on, probably around 1000oC to assist the reduction. It made a big difference to the comfort of my knees which would be scalded without the door. It was along hard firing this one, the longest so far at 15 hours, damp wood, cold south westerly wind all having an effect. The rain held off. I thought that the wind in this direction would speed it up as it blows directly at the fire mouth, my perception is the opposite. Will have to try it again with drier wood.

happy kiln = happy potter,

  This was a much better firing, even though I could hardly walk the next day - 15 hours on concrete in the wrong shoes.
will post some results next.
I think this blog is getting repetitive, not enough crises with this kiln. By the look of the interior it will need a rebuild before the chimney wall slumps.
Meanwhile I have been planning an anagama firing at Higham Hall in Cumbria for November.

Firing 13 - lucky for some

But not for me!

Work to go in 

7am, 90oC after 2 hours, turn up the gas, cup of tea, breathe deep

Gorgeous day, Nice, easy and steady climb to 1200 then 15minutes of lost concentration and I never got it back above 1180. I knew the cones were telling me to keep going but after 13 hours the lure of fish and chips at the pub was too great (and there was a bit of applied pressure from R pushing me in that direction).

Lesson learned - instead of only another 2 hours to get to temperature I now have a whole 13 hour firing to do and on my own as R will be away. I think I'll go to 15 hours just to be sure. Have to say I'm hacked off. Not getting enough results to feed the passion. And to continue the misery, the kiln is showing distinct signs of ware, but that's another blog

Orton 7 8 9 & 10, obviously underfired, 9 should be well down

 However, I look at the photo of the sunrise and find there the consolation. 

I found an article about a similar kiln in back issue no. 18 of The Log Book (The International Woodfired Ceramics Publication) www.thelogbook.net built by Petr Novak in the Czech Republic. He refers to it a fast firing kiln with ‘circulating flame’, possibly of German design from 1970s. When I bought my kiln Mr. Krajek implied that it was a well know design in Central Europe. I’m surprised not to have come across it before in UK but perhaps there are fewer opportunities to wood fire here. There is a seemingly endless supply of wood in CR which has huge areas of managed forest and woodland and wood is a common fuel for heating homes. In fact I know of at least 4 ceramists specialising in building ceramic stoves in the small area of Česky Krumlov (south Bohemia) but that is a whole other subject. And talking of Česky Krumlov (a wonderful UNESCO world heritage site with CR’s 2nd largest castle) in the museum there is a beautiful scale model of the town made in ceramic by Jana & Petr Pešek.