Tag Archives: glazes

Processing Clay and Ash

In a recent massive cleaning around and in the studio, I changed things around to utilize some of the outside space more efficiently. One of the most important things is that I now, again, have a setup for processing clay and ash that I have collected and burned.

I had been getting close to finishing off my stores of collected clay that I processed some years back, time to start doing it again. I think I have a better system this time, and I have an inexhaustible supply of pine ash for now, too.

I have buckets, bags, and jars full of old collected clay and dry trimmings that need recycling. It should take some months to get it all blunged and pugged.

Collected clay that has literally been sitting around for years.
Collected clay that has literally been sitting around for years.

The Choppage ‘cho’ ‘pah’ gay’, is a traditional Korean tool for scooping off clay and other materials without disturbing everything underneath. It works much better than a ladle. I couldn’t find anyone who made them anymore, but my mentor still had one which is kindly letting me borrow.

Clay washing bucket setup, and scooping tool, called choppage.
Clay washing bucket setup, and scooping tool, called choppage.

I just agitate the material in the bottom bucket, wait, and scoop off the stuff that settles last.
Then, later after it settles in the upper bucket, I siphon the water back down into the main bucket. When enough of the upper bucket fills with material, I dump it into cloth lined basket or plaster to get out the excess water.

After returning water back into the main bucket from the 'good stuff' bucket.
After returning water back into the main bucket from the ‘good stuff’ bucket.

With the ash, the process is the same, but after I get out the good fine ash I transfer it into another bucket and wash it some more to get out the nasties. The nasties cause problems with glazing sometimes and I don’t like them. I do save the water containing the nasties for other uses.

Pine ash bucket setup, main on bottom, fine up top.
Pine ash bucket setup, main on bottom, fine up top.

The leftover rough ash stuff seems like a waste to just throw away, so I am thinking about ball milling it to see if it can be useful in some other way. We’ll see…

The leftovers after the good stuff is scooped off.
The leftovers after the good stuff is scooped off.

 

Scooping with the choppage tool.
Scooping with the choppage tool.

The sieve is 120 mesh, because I lucked into a cheap recycled sieve. I would usually use 100 mesh, so it is not much of a difference.

Dumping through sieve which is sitting on the bucket mouth.
Dumping through sieve which is sitting on the bucket mouth.

Aging pots

Lately I’ve been experimenting with ways to age pots more quickly, making the crackle stand out. This time I tried an old woodworking trick, and it seems to work nicely.

I soaked the pots in a strong tea bath then dried completely.  After that, I applied iron acetate with a brush and let them sit a couple of days. The iron acetate reacts with tannins and turns a dark color within about 3 days. I made the iron acetate by soaking steel wool in vinegar. I may change to a weak sulfuric acid solution, since the smell of the vinegar is proving difficult to get out of the pots!

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At long last…

… some pictures of new fired/finished work. Finally got my brightness and white balance issues resolved and took a few pictures to share with everyone.

I hope you enjoy them…

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.

glaze crawling a bit

There was a bit of an issue with crawling over one of my clay bodies, when raw glazed. The guinomi toward the front of the kiln had this problem, but melted enough to look interesting. These bowls at the back just look dangerous. I left them after the last firing, but finally got them out yesterday and had a nice cathartic smash fest.