Halloween night shift

10pm to 2 am shift on Halloween - owls hooting, something skreetching and a little devil showing its horns. 
A few bricks got knocked off the outer layer of arch bricks but they're wedged back on and now we really do have to plan a rebuild. 
 After 3 hours soaking at 900 we changed shift and aimed for 1100 by 2 am. Then soaked in reduction for half an hour to encourage some orange in the shino glaze.  Top vents covered, damper in and a singed hairline at the next stoke as the kiln blew back out of the firebox. Next stoke open the damper first. 
Gavin stayed for our shift and was still going when the rest of his team arrived at 2. The man is an instiable firer. Will he still be there when I go down for breakfast now at 10.30? 

Skye Wood Fire: Anagama in Cumbria

Anagama in Cumbria

November in Cumbria is not the best time for a firing but it's still better than Skye has been this year.
Ten of us arrived at Higham Hall yesterday, 6 tons of wood waiting for us under tarpaulins and a sad looking kiln. Last years winter frost has caused a bit of heave and the arch is looking distinctly flat. Should hold up and Gavins big pots are strong enough to withstand a collapse so they're at the front!  
This is a much tighter pack than last year. Lots more pots, new shelves and props. About 4 hours to pack (photos later) and brick up the door. Gas on low overnight to dry it out after 14 months of Cumbrian weather. 120 C at 6am this morning. Small wood fire in the ash pit and up to 240 C by 10 am. That's me off shift until 22.00 but we're aing for 800C by 18.00.

Firing 21

Firing 21
5am first sign of dawn. Cloudy but dry with south westerly breezes. Discovered I am very low on gas for the initial warm up. Stupid oversight, hope the local shop has a bottle in store as I have a lot of raku firing to do too - not today though. (When I started rakuing 15 years ago a 19kg bottle of propane cost £11 today it cost £38). Awake again at 7 and the gas has lasted, kiln at about 100 C. Turn gas up and back in to make tea only to find Non Potting Partner has already made it (all previous complaints withdrawn).
Start to feed wood in around 8 o'clock and continue with both until 9.30. Turn the gas off expecting quiet to descend only to hear the rumble of the forest being felled (mustn't complain it's community owned now and I'm thinking of all that scrap wood to be gleaned) and then NPP starts up the mower to cut the lawn.
A few spots of rain, a crunchy James Grieve apple fresh from the tree and into the rhythm of stoking, concentrating now to avoid losing temperature. The last few firings have followed a very close pattern, apart from the previous one fired in a south westerly gale and an hour faster.

More tests in this kiln. Trying to find a white shino type glaze which gives results with this firing cycle. I have a rather drab white which matures but is dull, and a lovelier snowy white one maturing at cone 10 which I struggle to achieve. There are also tests with the new Scarva black body which has been firing very black but very dry and needs a little sheen or sparkle to liven it up a bit. Plus, of course more pieces for Philadelphia.

1000 C at 12.40
1100 C at  2pm
1200 C at  6.30pm

Firings 16 & 17

I'm writing this in the middle of the 3rd firing since the rebuild.
The first, no. 17 zoomed up to 900 in 7 hours (weather not a factor, overcast and light breeze) then stalled around 1100 for about 4 hours. After 13 hours I managed to coax it up to 1200. Where it stuck for another 2 hours reaching 1240 tops but acheiving cone 9 down.
The results included some lovely carbon trapping in a soda ash glaze I was testing.
For firing 18 I attempted to follow the previous cycle to get the carbon trapping effects again. The weather was breezy from the south west so not too different.
I reduced for an hour at 900 but not a heavy reduction, as the breeze was blowing directly into the firebox. The kiln stalled again between 1120 and 1170 for about 5 hours. Reaching 1218 tops but with cone 9 only just starting to go after16 hours, by which time I was completely gone, so clammed up and headed for a hot bath.
I then had to wait 2 whole weeks on an annoying holiday before I could unpack this kiln. That's the trouble with non potting partners they don't really understand what's the priority. Actually I did prize open the lid for a quick peek just to reassure myself it wasn't a disaster, that would have really spoiled the holiday.


I should mention here the benefits of non-potting partners - coffee, breakfast, lunch, dinner, cups of tea, that magnificent cold, cold beer at 6 o'clock with the kiln at 1200 Centigrade after 13 hours of continuous firing, all brought to me with barely a hint required.

Rebuilding the kiln

The broken shelf which curtailed firing 16 gave me a chance to assess the. Condition of the kiln after 15 full firings. I removed the broken pieces of the shelf but couldn't get a whole new one back in it's place. The brickwork has shifted quite a lot with all the expansion and contraction of the firings.

 I had to unbuild most of the kiln anyway so I took the chance and went right down to the base. I had been concerned that the bed of sand on which the whole kiln sits may have eroded away.  But no, that is as good as new. What I should have been worried about was the chimney.
You can see the gap of about 2cm down the left hand corner of the chamber.
The internal chimney wall was listing away from the chamber and in danger of collapsing into the flue. As this wall is free standing it seems inevitable that this will happen and I'm lucky that the floor shelf went first.

These are fire bars at the rear of the fire box,  pretty well fused by ash, embers and the effects of the soda going in that way. All the soft brick back wall of the chamber was also very crusty. Time to reassess the soda?  The soft HTI bricks don't like it. I rebuilt that part using all the spare hard fire brick I had, taking some from the front of the fire mouth.

The chimney wall is strengthened by laying the bricks flat and increasing the size of the pillars on which they stand even though this reduces the flue area, and by tying the top course of brick into the side walls of the kiln. The chimney is also taller than the original design by 2 courses which takes the smoke away more effectively. Two firings later and it doesn't seem to be affecting the firing except perhaps for the better. It seems to climb more smoothly but perhaps that's because I've learnt not to get distracted.
The cooling has slowed down now that the new iron framework holds the fibre more snuggly to the walls. The iron is a little flimsy and will need modifying but it works well enough, especially the door.
All in all the rebuilt kiln is an improved one but I'm not sure I want to rebuild it every 15 or so firings. And of course it's just not big enough.........
I was at Aberystwyth a couple of weeks ago for the International Ceramics Festival. Had a brief chat with Joe- Mr Kiln -Finch.........

And here's the culprit

The offending shelf

 Thinking back to when I was packing this firing, there was a loud crack when I was filling the top shelf. As nothing moved then it just didn't occur to me that something had bust. There was no sign of a crack when I painted on the batt wash.

Half baked, smokey pots

I'm getting closer to wanting to build a more substantial kiln. With a proper arched roof and door into the chamber. In fact I've heard of some 2nd hand bricks needing a home....

The pots looked rather beautiful with their dusting of soot and ash and useful to see how the early ash settles on the surfaces.

So now the kiln is packed again and waiting for the weather to come good, the exhibition to end, the trip away to be over, the dog walker to be at home again etc etc