Firing #2: Unpacking

Unpacking the kiln revealed a more even distribution of heat compared to the first firing. I could see after cracking the door that I got the right temperature in most parts of the kiln. The very top of the kiln and the area just before the flue seem to be the coolest areas. My cloud glaze (chun) is fairly fussy, the thickness needs to be spot on and so does the temperature. After firing this glaze many times I can tell which one of these variables are lacking. On this occasion I think I got the thickness a bit wrong with some pots firing to a deep blue to black(clear). I am pleased with the firing though, a big improvement over last time.





Above: Cracking the door to see the pots.

The addition of the bag wall has definitely helped get the heat higher in the kiln. This time Cone 12 was down at the bottom with Cone 11 flat and Cone 12 bending at the top. I guess I will have to continue with slight modifications to the bagwall over the next few firings.







Above: The door completely down, cooler near flue but much improved.



Got temperature

I managed to get cone 11 down at about 4.30 pm. The glaze on the pots looked like it had melted. I will have to wait until I open the kiln to find out.

Cold start but going well

It was a crisp morning when I rose at 4.30 but the kiln started off well. I made a small fire in the kiln last night and let it burn down to preheat it a bit. So when I started this morning the kiln was warm and a little bellow 100 degrees. Burning odd bits under the grate works well. Especially when there are so many sticks lying around under the talk gums.

Packing the kiln

Because of favorable weather conditions I have decided to proceed with firing the kiln this weekend. I spent the best part of yesterday packing the kiln and getting things ready to fire today. I managed to fit all the work in except two pieces. Photo below shows final stages of packing.

I have started the firing now and have a small fire burning at the front of the kiln ( below the grate).

Preparing to fire

I have spent the last couple of Saturday's making up glaze recipes and applying them to my works. With this load of pots I have made a range of various sizes and explored some new forms. I am hoping that the range of sizes and variation of form will allow me to pack more work into the kiln and fire it more efficiently. The photo below shows all the pots for the next firing.

Kiln Modifications

I hope to do two more firings this year in the new kiln before it gets too hot and dry. This means I need to get busy creating enough work to fill the kiln twice! However, before I do the next firing I will need to do some modifications to the kiln. I am hoping these modifications will allow the kiln to fire more evenly. With the current design only the pots and shelves can deflect the flames and heat upwards. So during the last firing everything in the middle of the kiln fired well due to the flame being pulled directly across the kiln chamber (see below).

I am planning to build a bag wall inside the kiln to help deflect the flame upwards. The bricks will be laid in a checker board fashion, to leave holes that flames can pass through. This is so that all the heat is not directed up and then over the pots in the chamber, creating new problems (see below).

Student of the Red Brown Earth Exhibition 20 July to 5 August

Hi everyone,

Please find an invitation to my current exhibition above. The exhibition runs from 20 July to 5 August at the Strathnairn Gallery but please note the official opening is 6pm Friday 27 July. The exhibition will be opened by Greg Daly, Senior lecturer in the Ceramics workshop, ANU School of Art.

In the distance, 2012, stoneware bowls with washed dirt inclusions, iron bark (tenmoku) and cloud (chun) glazes.

Photo by Stuart Hay

The exhibition will feature some works (like the ones above and the one on the invitation) that have been wood fired in my new kiln which I built this year.

Spring Creek Kiln firing #1: A reflection

After evaluating the work coming out of the first firing I realise I will need to change a few things before the next firing. Firstly, I need to address the unevenness of the heat in the chamber. After doing some more research on kilns of similar design, the key areas seem to be:
 

*adding a bag wall inside the kiln to deflect the heat upwards

*pack the work in the kiln 'tighter' by packing more work in

*adjusting the firing cycle



It is definitely a learning experience.

Not bad for the first time

Despite the kiln being too hot at the front and too cold at the back. There was some pleasing results when I unpacked it late this afternoon. There will be a number of modifications I will make before the next firing in this kiln. This was the first firing in this kiln and there is a bit to learn to get operating optimally - not bad though, I am happy.

Full blast

I was able to get cone 12 down at the front of the kiln but much cooler at the back. I will have to look into how I can get this more even. Now I will just have to wait until its cool enough to unpack.

Begin reduction?

My pyrometer is reading 650 but cone 06 is down at the front ( top and bottom - 991. It looks that hot at the from however much cooler at the back of the kiln.

Getting hot

Firing going well have been in reduction ( limiting the amount of oxygen) for several hours. Looks hot but no action in the cones just yet.

Off to a good start

It was 7 degrees at 5 am this morning. I have started a fire under the grate and things are going well. It is slightly cloudy but hopefully the clouds won't bring rain.

Got packing

Packed all the work ready to be fired tomorrow. The kiln took more than expected. Finished packing and bricked in the door by 8.30 pm. I started packing at 3.

No trees were harmed

No trees will be harmed (at least not by me) in preparation for tomorrow's firing. I have collected a large amount of iron bark and pine. The iron bark was left by sleeper cutters and the pine has come from small trees which my grandfather "ringed barked" years ago.
I just now need to cut it all up!

Glazing pots

The bisque firing went well and today I applied glaze to these pieces. I have been experimenting with various glaze combinations for some time and continue to do so. I have to remember to carefully record the different glazes used on each pot in my journal. I am using nine different glazes in various combinations for this firing.

Busy making new work

I have spent the last week or so making pieces for the next firing. I have now made approx 25 pieces which are now being bisque fired. The recent wet weather slowed down the drying process somewhat but I eventually got them dry enough to fire ( I hope). I am pushing it - trying to get these pieces into next Wednesday's firing.

Kiln Construction: Day 6 & 7

 Due to the high amount of rainfall I wasn't able to commence work on the kiln again until Easter. So I spent Good Friday and Easter Saturday getting the kiln almost finished. I built the walls and added an additional metre to the height of the chimney.


Adding walls.

Wall, stoke hole and door.

Adding exterior wall.

  

End of day 6.



Adding additional height to the chimney.

Kiln just before sealing chimney with mud.

I now plan to return to fire the kiln very soon. I do however, need to create some work to go in it, prepare the wood and put a final layer of insulation (clay & sawdust) over the arch of the kiln.

Kiln Construction: Day 5

I set about constructing the dampers, chimney and removing the arch form during day five. This time without any major mishaps.

Constructing the dampers

Dampers for the chimney and passive dampers at the base were included

Kiln with the arch form removed

First section of the chimney added

Kiln Construction: Day 4

I returned to Canberra after day three. I didn't return until mid January when there was a cool change. This time I needed to complete the dampers and chimney. I had a slight mishap however, I got a bit too eager and tried to remove the form from the arch by myself. The form twisted when I tried to remove it and knocked the whole arch and firebox down. I had to reconstruct the firebox and arch all over again!  This error cost me an extra day.

Oops! Start again...Kiln cleared ready to rebuild.

Reconstruction of the arch take two.

Front of the kiln with extra layer of bricks and stone buttressing







Kiln Construction: Day 3

Day three of the kiln construction saw the hot weather continue. The first thing I attempted to do was to complete the flues.

A passive damper was created for each of the exit flues into the chimney as shown below.

The form for the arch was then placed on the kiln floor using bricks to raise it so it could be removed later on.

Bricks were then laid to follow the arch.

The arch was eventually completed by placing the last key bricks in the top of the arch.

Kiln Construction: Day 2

Construction on day two started early as the weather forcast was for a max of 34 Celsius . First was the construction of the firebox.

I then started construction on the platform (kiln floor) which needed to be lifted up above ground level. To do this I used large stones and broken brick to fill gaps.

A course of red brick was laid on top of the stone platform and leveled with a fireclay and sand mix before the firebrick floor was laid.

Kiln Construction: Day 1

After traveling from Parkes with the last load of fire bricks it was time to start construction. Common bricks, stone and rubble will be used to support the chamber floor. Local red bricks will be used as foundation under the firebox and chamber floor. It is a hot day but I start digging out a hole for the firebox. Fortunately the heavy clay soil is moist but heavy none the less.




Kiln site - gravel only




Red Bricks at the rear of the site



Digging room for the firebox

Initial layer of redbrick laid on a thin layer of sand\gravel



2nd Course of red brick with firebrick for mouseholes (air inlets for under the floor)





Knock off time - firebox floor complete