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In the hot seat

A couple of days ago I sat down with my newly acquired kickwheel to see what I could do. I’ve used my homemade kickwheel frequently for handbuilding and paddle work, not as much for throwing, because it is quite tall and the flywheel is quite high from the floor.

The new kickwheel is craftsman made, and shorter, making it easier to use without a special seat. In the two days of throwing, I discovered two things: 1. my homemade wheel spins better making it great for coil and paddle work, and 2. The new kickwheel is easier to throw on because the fly wheel is so much closer to the ground.

I decided to throw with a difficult body to keep things interesting. Stamped Izumiyama porcelain stone that had been levigated and filter pressed, with the removed large particle material re-added as 30% of the body. This makes for a pretty short body but it does have more backbone than straight filtered Izumiyama. I started with small, simple shapes for the first day, and moved to larger bowls on the second, sort of a cross between an Ido form and a wider more open shape typified in a lot of Ri period Korean work.

My goal was to keep things as light as possible off the wheel, and requiring as little trimming as possible.

I waited a bit too long with the small cups, but they trimmed with some very nice texture even though a few had some of that soft porcelain tear-out. Since they are sake ware, I’m hoping this will add to their landscape in the firing.

Very happy overall with the texture of the interior of the feet. When I first discovered that porcelain would trim like this, it was a major discovery for me, and prompted me to start working with it.

Clay clay clay

When I was polishing work from the fall firing yesterday, I noticed two pieces that had been glazed, fired (on shells)glazed again, and fired again (on shells). This isn’t too unusual, but in the case of these two pieces, they were literally fired side by side both times and had the same glazes applied, twice.

The only difference between the pieces is the clay body. The teabowl is clay/sandstone 50/50, and the smaller cup is clay/sandstone 10/90.

Now probably it shouldn’t, but the difference in the fired glaze surface astounds me. And all other things being equal, it must be that 40% difference in clay content that has changed that glaze.

Since the glaze is collected, I don’t have an analysis, but my guess is that the higher alumina content in the higher clay body is responsible for making that high silica glaze go clear, by adding alumina to the glaze matrix and fluxing more of the silica.

Loading has begun

Loading of the first chamber began this morning. 
The stack starts at the bottom from back to front. This part of the firing process is very important because it determines where the fire and heat will go during the firing. A bad stack means you will have poor circulation and you’ve doomed the firing even before you’ve lit the fire. 

The bottom of the stack is pretty much done, and the ware from 9 ware boards got stacked in there, which is about 80 pots give or take a few. 

Let them eat cake

Here is my latest pot porn for you: freshly stamp milled, slaked, and filter pressed cakes of Izumiyama porcelain. 150kg. 


Not for the faint of heart, Izumiyama is hard to work with. It is non plastic and likes to crack during drying, impossible for slab work, and deforms easily. And it costs more than twice as much as Amakusa porcelain from Kumamoto. Most porcelain artists in Arita and Imari switched to using Amakusa porcelain long ago because it’s much easier to work with, doesn’t crack, and fires whiter. 


BUT! The beauty of Izumiyama in the wood kiln is absolutely undeniable. It fires to a soft ivory white and blushes in very subtle shades of peach. The surface is deep and translucent and vitrifies as low as around 1230C. 

Tomorrow morning first thing, Peter the Pugger will be getting a major workout!