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.

As I haven’t got a firing planned for the near future I wanted to write a brief description of the first wood firing. Not just the first in this kiln but my first ever. I hadn’t even helped or watched someone else’s firing. My college experience all took place on the third floor of a central London art school building, no wonder they didn’t encourage woodfiring. The closest I have been to a full firing was Joe Finch demonstrating a gas/wood firing for the Scottish Potters in 2007.
After building this small kiln and reading various books and articles I still wasn’t confident but there came a point in late spring when I was on my own at home and I thought ‘I’ve just got to do it and to heck with the results’.
I packed the kiln with oddments and experiments and shoved my raku gas burner into the fire mouth to dry the kiln out slowly for 2 or 3 hours (the west coast of Scotland has high humidity). I planned to fire to cone 6 to start with, not knowing how long it would take, but I put cones 7 & 8 in too, to be safe. And I thought I would bung in some soda too for effect.

5am the next day with the sun already rising behind the mountains across the Sound, I stumbled out of bed to relight the gas on low. Having no idea how long it would all take and because I was firing solo I had decided to go up to 250°C with gas (which meant another hour back in bed).
7am I was back at the kiln with cup of tea, turning up the gas.
8am I started feeding in small pieces of wood along with the burner.
8.30 larger pieces started going in
9.00 gas was turned off and silence descended apart for the birds singing and the crackle of wood burning. I fed another piece of wood into the fire and the peace felt as wide as the view. Now I know why I do this, I have a sense of completing the cycle which I don’t get from electric firing and almost get from raku firing but not quite.

The firing continued as with the subsequent ones. I put in soda soaked wood into the fire at about 1150 (about 500g soda) It was remarkably easy to get the kiln to cone 6 down so I continued until the pyrometer read 1250°C and cone 8 was bending at the tip on the top shelf. I allowed the fire to burn down a bit then bricked up the fire mouth and the chimney and retired.
The next day the temperature was at 250°C and by the evening cool enough to unpack. (After 10 firings I am trying to slow down the cooling by firing down to 1100°C and with extra panels of insulation). The results were pretty unremarkable but so exciting to feel the weight and density of the stoneware and follow the path of the flames in the markings across the pots

This was the perfect day. The sun shone warmly in a cloudless blue sky (no midgies (wee biting monsters)yet). A gentle breeze wafted away the smoke and nothing to distract from the feeding the fire and enjoying being alive.

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.

Pots from firing no.9

Interior of the kiln from the side

You can see the build up of glaze from the soda on the bricks. The first firing gave them the most beautiful orange blush. I realised that I should protect them with a wash of alumina. I've no idea how long they will last or how viable it is to do this kind of firing in a kiln which has to be unbuilt to unpack.

I used about 500g of soda for this firing which went into the kiln at about 1170 C over half an hour giving the work a light soda glazing on their exterior surfaces.

These are the best pieces from this firing. Each of the pots has a transparent liner glaze on the interior.

Lidded terrine

ht 13cm

width 21cm

Casserole, makes a good coq au vin.

Slightly ovoid,

ht 10cm

width 23cm

Deep oval vessel

soda glazed

ht 15cm

width 20cm

Deep oval vessel

ht 15cm

width 17cm

Jug with no handle

ht 13cm

width 18cm

Firing number 9 20 January 2010

I know it isn’t in chronological order but this is the most recent firing and the first of 2010.

Got up in the dark just before 6am and pulled several layers on top of my pyjamas. Cold and windy, gusting from the south east on the most exposed side of the kiln. But dry. I warmed the kiln through for 4 hours yesterday evening to dry everything out.

6am lit the gas burner, less than 0.1 psi, once the flame had stabilised back to bed.
7.30 Up again; dress properly and down to the kiln with cup of tea.
8.0 75°C 2hrs Gas up
8.30 140°C Small pieces of wood in.
9.00 180°C 3hrs larger pieces of wood catching, breakfast arrives, very good porridge.

10.00 398°C 4hrs Dry, S.E. 5to 6
11.00 597°C 5hrs
12.00 805°C 6hrs Coffee arrives
12.30 first heavy smoke from chimney at 860°C
First flames from chimney at 975°C
1.00 1000°C 7hrs
2.00 1100°C 8hrs Rain for next hour or so
3.00 1160°C 9hrs Heavy smoke
3.20 1170°C First soda in
3.30 1175°C Temperature fluctuating
3.35 1170°C Second soda in. Cone 5 mid kiln down, cone 5 at side spy hole bending
3.55 1200°C Last soda in.
4.00 1215°C 10hrs
4.20 1213°C Cone 7 mid kiln down, cone 8 beginning to bend
4.30 1220°C End of firing, start to fire down for hour or two
5.00 1100°C 11hrs brick up fire box, leave mouse hole open
6.00 905°C 12hrs reduce chimney hole to one brick, seal mouse hole.


I feed wood into the fire box and then reduce the draft by putting a brick in the fire mouth.
The kiln seems to stall somewhat at about 1080°C at which point I stop using the brick in the fire mouth.
After this I have to rake the embers to keep them down to get sufficient draft through the mouse hole.
I used about 500g bicarbonate of soda, mixed to a thick past with water. I put this onto thin pieces of wood, dry them out on top of the kiln and introduce them into the fire box one at a time. When the bright orange sodium flame diminishes I add the next one.
It wasn’t the most peaceful of firings (that was the very first) as Bertie the dog went to visit his girlfriend and R had to search for him (therefore the tea wasn’t supplied so regularly), then was some chain sawing and car hovering, but at least I could shut the radio up.

building the wood fired kiln

A few pictures of the kiln build. May 2009

The base of the kiln. A bed of sand under a layer of common house bricks.

Complete layer of high temperature insulation brick (HTI 26)

First course of HTI’s. Firebox mouth at front. (firebars lying to the right)

Fire bars in place, front and rear bricks cut to form ledges, small pieces of HTI as spacers.

Next 3 courses showing firebox mouth. Extruded hollow kiln shelves forming roof of firebox and floor of ware chamber.

Rear of kiln showing kiln floor, inner wall of chimney supported by cut bricks to form flue.

Position for bag wall (formed from cut kiln shelf balanced on edge).

View from above of chimney being constructed, one brick in depth.

Completed kiln chamber. Pyrometer hole can just be seen in the middle of the penultimate course on the long side.


Kiln shelves forming roof with 2 layers of fibre. End wall has been rebuilt to include loose half brick as spy hole.

I’d just like to point out that all the sunny pictures are from Skye in June!

The next step is to fire it, or read a few more books about it first.