Tag Archives: karatsupots

Kiln Loading

The date for the fall firing is official! 2011/11/11. There must be some sort of astrological significance to this, be it good or bad.

Since I’ve been making a lot or work to go into the kiln for this firing, I’ve been constantly short on ware boards, so decided the best way to free some up would be to get the pots off of them by loading them into the kiln. This has the added benefit of breaking up the loading process so it is not so danged exhausting.

This afternoon saw the completion of the rear setting, all cone 6 ware give or take. E-Karatsu, Kawakujira, and Kohiki. Most everything is smaller and doesn’t have much height, so to fill in the higher spaces many of the pots were balanced on kiln posts. The added benefit to this is that if the temperature gets too high, the pots will collapse, invert around the posts and stick to them completely and utterly. Post-In-A-Cup.

The two jars are refires that had a lot of unmelted ash on the shoulders. In order to melt it, I’ve applied an ash glaze that should melt and flux the sintered ash underneath, hopefully. And, if I’m really lucky, they will slump or split in the firing, sticking to everything around them.

Kishidake Clay

Although I dig a lot of my own clay, every now and then I find a bagged clay that I like, and use it for certain projects. Since getting the big wood kiln, I’ve done more of this, because I can blow a lot of clay in one firing, and wasting collected clays is a real waste of time and effort. Once I’ve nailed down how to fire the woodie, I’ll go back to my collected clays since my loss rate will be much less (or at least here’s hoping).

Shoko Todo in Ureshino has a couple of clays I like, one of them is called Karatsu Kishidake because the base clay in the formula is from the Kishidake area. It also contains a lot of very fine sand, which is something I really like. Still, I like to add things to bagged clay to improve it, and this is no exception. If a lot of fine sand is good, then a lot lot must be better, right? Perhaps not.

I started by adding about 15% of my own sand to the clay, and to my surprise it improved the workability, giving the clay more backbone. It also gave the trimmed surfaces more character.

For the next hump, I added about 25% extra sand. I should have known I was in trouble when I couldn’t even wedge the stuff without it splitting apart and having chunks fall out, sticking to the table more than the clay lump. When I started throwing the hump on the wheel, pots would split vertically as I pulled the walls, and I couldn’t get near as thin as with the 15% sand/clay mix. Most of the bowls I managed to finish still had rips in them that I had to go back and fix later. When trimming, this clay gave a very rough texture, and I really liked it, but not enough to go through the frustration of throwing the stuff again. Although, for small things like guinomi this clay is the bomb.

Below in the pictures are two trimmed feet for comparison. One is the 15% mix and the other 25%.

Teapots again

The simple handle-less teapots that I fired in the last wood kiln load all sold, which is very good news. Granted, not a lot of them survived the firing because wood tumbled over on them during the stokes. Not making that mistake again, combined with a larger batch of pots this time around should give me a good little stock of pots to sell.

These are spoutless, handle-less teapots, with vertical grooves cut on the interior where the mouth is, to allow the liquid to escape. They work surprisingly well, and are far easier to clean than a standard teapot strainer.

Also, (my apologies to the squeamish here) I ran into a strange thing on the way home the other day. A Praying Mantis had been run over on the road and its internal parasite was coming out. I couldn’t resist snapping a couple of pictures. These Gordian worms, or horse hair worms as they are sometimes called, really creep me out.

Kohiki cups cont…

I finished the deco on the cups from the previous post a couple days back, and glazed them. After doing the iron brush deco, I gave them a THIN coat of clear glaze, very watery: about 32 on the hygrometer. The deco images were visible under the glaze when it was still wet, though once dry it was no longer transparent.

Here are the images of one of the cups before the glaze was applied.

Kohiki tea cups, etc…

When Nishioka Koju passed a few years ago, a friend of a friend got some of the warehoused clay from one of Koju san’s storage areas. I was  able to get about 60kg of raw dry clay and have been waiting for the right opportunity to use it. I tested it a couple of years ago in the gas kiln and decided it needed wood to really make it jump. The clay itself is a light grey, almost white when dry, so I thought it might be fairly low in iron, but tests showed it to have significant iron and not very refractory. Probably good at around cone 6.

I made a run of about 40 cups yesterday and trimmed them this morning,  then waited for them to firm up a bit. Then, in the afternoon I applied the white slip (kohiki). This was something I have never done before on wet greenware. Last firing I tried it on dry greenware with success, but that clay was different and pretty stable for raw glazing. This clay is quite different so I didn’t know what to expect.  Many sources say to slip the inside, then let it dry, then slip the outside, to prevent the pot from collapsing. The problem with this is that you end up with too much slip around the lip of the pot, and more work is required to clean it off. I decided to apply to the whole piece at once, and did just one test piece to see what would happen. After 30 minutes the pot was still in one piece so I went ahead and did the whole group of 40.

I really like what the slip does on a wet pot. There is a lot more flow and variation in thickness, and I suspect better adhesion too. After the slip dries I will do some brush deco and give them a thin coat of clear.

At the end of the hump, there was enough left for a teabowl, so I threw one. It is intended to be a Todoya style Korean bowl, but we’ll have to see what happens in the firing. At least, this clay trims real nice. Unfortunately the bowl would not hang on to the trimming chuck, so that is the reason for the abrupt end on the interior of the ring. So as not to end up with nasty chuck rash, coupled with over trimmed foot syndrome, it got left as is. Usually trying to fix something like this just ends in disaster…

An odd experience

Coming home on Friday, I noticed I was behind a tanker truck which was polished stainless steel. The convex rear of the tank, coupled with the polished surface, made a very nice ‘fish eye lens’ type of mirror.
The odd part of it was: watching myself in the rear of that truck, I could see my car and all of the landscape around me rushing by, but it was as if I was watching me as someone else, or like watching myself in a movie, but in real time. It was kinda cool. I tried snapping some pictures with my phone camera, but they don’t really convey the experience.