porcelain

2015 Christmas Firing

was a real nail biter.  At 4am, 10 hours into the firing, I realized that I had not gauged my propane reserves properly, when I looked at the tanks and realized that they were only about 1/5 full and covered with a thick layer of ice. I immediately put the water hose on them to melt the ice and keep them from freezing again, then I chewed my nails until 8:30 am when I could finally call the gas company for fresh tanks. They arrived just after 9am, and good thing to because I only had about 2 inches of fuel left in the tanks at that point.

The firing ran a total of about 18 hours, which is fairly normal for this type of firing, and most things came out ok, with a few exceptions:

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.

8th Wood Firing Photo Record

This post is a photo record with comments, in order to organize and retain my thoughts and observations about the 8th firing of the wood kiln. I always think I’ll remember until the next firing, but never do. So, if you get into this, beware there are a LOT of pictures, some of which may seem redundant. There are examples of most of the pots from the firing, minus teabowls and some others which are not photographed yet.

The 8th firing was a charm overall, with many good pots, some bad, and some that will get refired. Kiln was fired in oxidation primarily. We stoked once every 30 minutes for 2 1/2 days, then once every 20 minutes the last half day.

– Front was nicely melted, nice even gradient to the rear of first chamber, E-Karatsu was about ideal. Cone 12 at hottest front down to cone 6 at coolest rear.

– Front chamber behaves like anagama. No significant temp gradient from front to back of each setting. Next firing, will pack kiln by eliminating the space between settings, leaving horizontal space for flame travel. One long setting from front to back of first chamber.

– Ame yu better at low temps. Load rear to mid chamber.

– Ao yu needs more heat, mid to front chamber.

– Large platters go midway to back of front chamber. Too much ash up front.

– Firebox wares are very nice in a three day firing. Great place for Shino, under cover to avoid ash in pots.

– Rear chamber fires fast when preheated for 3 days. Jumped from 1044C to 1344C in four stokes, a little over an hour. Care must be taken to spend more time soaking at high temp, because rear chamber high temp wares not quite mature (surface changes only), clay not melted well. Spend 3 or 4 hours firing off rear chamber, slowly, to get inside the pots.

– Rear chamber fires very evenly front to back, and top to bottom. Pick a temp to fire at and load accordingly. Don’t expect a significant gradient.

 

Plates for February

Here are some of the things that will go into the Feb. firing. Small plates that will be about 12cm fired, and some larger plates about 24cm fired.  Clay body is Karatsu white from Hara san and Kishidake clay 50/50, with pulverized sandstone and weathered Shirakawa porcelain stone wedged in.

Shirakawa Porcelain Mine

Took a hike up the mountain today to the now closed Shirakawa Toseki (porcelain stone) mine. This was the base ingredient for Arita’s glazes for hundreds of years. The mine is extensive, but I stayed near the entrance as old mines are not among the safest places on this earth. The passages from the main entrance radiated out in several directions and where light still filtered in, you could see that some of them extended several hundred meters. And that is just what you could see from the light filtering in. Who knows how much farther they go?

In the entrance area, pillars of rock were left to hold up the roof, but there were boulders in several places on the floor, from what looked like recent rock falls. The roof of the cave is probably about 20 feet tall. The expanse of white rock is really stunning to see.