Category Archives: wood kiln

Fall Open Studio

Just a short post of some pictures from the studio sale this weekend.

Pieces and notes fall firing 2014

Fall 2014 Wood Firing Continued

The unloaded pots have now been hammered, moved inside the studio, or are getting refired. The ones that have been moved inside the studio are starting to get cleaned up and polished, in preparation for next spring’s shows.

All in all, there were some 750+- pots in this load. I’m not sure of an exact number because I started smashing before I had a count.

Here are some of the pots that I started cleaning up today. Most of them are small  dishes, ranging from 10 – 17cm across.  All sizes listed are width, and are approximate measurements.

2014 Fall Firing: Unloading the Kiln

Here are images from Saturday’s unloading of the kiln.  Some good, some bad, but mostly good.

Most problems came from mistakes made with clay or glazes, the firing of the kiln was exactly how I planned… first time ever.

Got a nice gradient from about cone 12-13 in front, to cone 6-7 in the back of the first chamber, and an overall cone 6-7 in the rear chamber.

Biggest problem was crawling of iron brushwork on raw ware. I will touch up bare spots and refire these.

Lost both big slabs, which both cracked BADLY.

Madara  and E-Madara items came out really nice overall, with lots of subtle blues.

I have this recurring nightmare…

before every firing of the wood kiln. Actually it is four separate recurring nightmares. In the first, I am loading pots onto normal wood shelves in a fairly standard living room, for some reason not worrying that the lot of it will burn up with the entire house. BUT, for some reason, I always remove all of the lamps and light fixtures, because they and they alone can’t handle the  high temps.

In the second, we are firing the kiln as usual, and we are into the third day, just hours before finishing and I realize that I FORGOT TO LOAD THE KILN… This one is by far the worst of the dreams. The feeling of sudden panic is positively sublime. Very happy to wake up (and realize it was just a dream) after this one…

The next is not quite as bad as the previous, but still pretty unsettling.  It starts out well enough: I have just unloaded a very successful firing and am so happy with it that I decide to fire again. Because it is a dream, I miraculously have enough glazed ware to load the kiln up again in about 2 days (Normally takes me 10). I get everything loaded, and start the fire, but about a day into the firing I realize I ONLY HAVE ONE DAY WORTH OF FIREWOOD! This one also wakes me up with that icky panicky feeling.

The third is not a nightmare per se, but a recurring dream about a kiln that doesn’t exist. It is a large single chamber, with white interior, and there are shelves on the walls and in the center of the large chamber on a sort of island. The floor, walls, and island are all white and rough with kiln wash. There is no chimney, and the kiln is connected to the fire box via an elevated brick tunnel, which goes out the rear of the chamber about 2 meters, turns 90 degrees right, stretches about 8 meters, then takes another 90 degree right turn, where extends forward and turns into the firebox. From the firebox to the kiln forms a large U shape. Even more strange, the firebox is open to the sky and steps up to the flue channel, which somehow ‘sucks’ in the heat of the fire. The firebox is probably 4 meters long/deep, and the wood used is huge: entire tree trunks shoved in and stacked in a criss cross pattern, burning.  Any one have a kiln that looks like this?

Coming up to this fall firing in Oct., I feel as though everything is under control, and no particularly strong feelings of anxiety, yet the dreams continue, including 2 nights in a row now, a dream of some of my teeth falling out. Seems quite normal in the dream at least…

Postfire thoughts

Well, time to sit down with the last firing and figure out what went wrong, and what went right.

Firing and packing: Great. With this firing I figured out, FINALLY, the proper exit flue volume to use. And with it, the proper packing procedure. The kiln climbed steadily, without effort, for 45 hours and the flame in the front chamber reached front to back really nicely. It turned out to be a fairly even gradient from front to back, from cone 13 in front, to a good melted 8 in back. No sidestoking necessary.
I am going to go back to using a pyrometer for the next firing, because this firing got very reduced. I think the stoke intervals were too close, and a pyrometer may help me get a better idea of temp climb timing, and when each cycle goes into oxidation.
At one point, when we switched to stoking the 2nd chamber, the temp just started dropping. You could tell from the sound and color of the kiln. I jabbed a pyro into a peep hole and it told me right away that I was stoking to frequently. After the flame had receded into the chimney and peepholes, and the roar had died away was when the temp really started climbing in the chamber. I had been stoking when the flames receded and the kiln quieted down, but once I started waiting rather for the temp to start dropping after the rise, the kiln got back on track. This rise took longer than I imagined, sometimes up to 10 minutes. Had been stoking waaayyyyyy too much.
This firing was a watershed moment for me, regarding packing, air, and stoking. I think next time will finally be the load that makes us all smile.

Glazes: Glazed ware in the second chamber turned out really nice. Reduction was still too heavy, but we got nice surfaces. Still, I won’t aim for that in the future. Madara glazes were too yellow for my taste. The first chamber glazes were so reduced that whatever their intended color, everything turned out a semi matte green, from the excessive iron pulled from the body saturating the glaze and crystallizing. I think the stoking interval will fix this problem.

Clay body: Oops. Here is where the shit hit the fan. Too much iron, especially considering the temp and amount of reduction that happened. The clay I used for the large pieces has too much iron for that type of firing environment, which is why they almost all collapsed. Having worked with a gas kiln for so long, it is hard to get out of the mindset of adding iron rich clay to other whiter bodies in order to get a desired color. The white clays in this area have enough iron for good color in a wood kiln. I keep forgetting that, but perhaps the shock of this latest meltdown, and the subsequent pain of shelf grinding will serve to jog my memory whenever I’m mixing clay for the wood kiln.

We got this off the shelf in one piece! The attached cup sits level when you set the piece on a table, so great for sashimi and  sauce or condiments.
We got this off the shelf in one piece! The attached cup sits level when you set the piece on a table, so great for sashimi and sauce or condiments.
The Fall of Icarus
The Fall of Icarus
Arm detail
Arm detail