Tag Archives: chawan

Gas Firing 2016.02.20 Comments and Notes

This firing of the kiln went too long, resulting in Orton cone 11 flat.  Ideally, it would be cone 11 touching, then sagging a bit.

Upon unloading the kiln this morning, one thing was immediately apparent: the right side was far more reduced than the left. Yellower glazes and more slumping. Even on the left side there was some slumping, because of the excessive temp., and because of the clay which contained some low temp high iron clay to help seal the ware against leakage.

Left side, sagging only slightly, white surface.
Left side, sagging only slightly, white surface.
Right side sagging badly, white glaze turned yellow.
Right side sagging badly, white glaze turned yellow.

Chosen Karatsu came out pretty good, but the white was on too heavy, running down the pots too much.  It still came out looking ok because of the clay.

Most of the teabowls warped or sagged, so I only get to keep 2 or 3 of the 15. This is why teabowls are expensive, kids…IMG_3399 IMG_3398

All in all, not a bad firing, but need to adjust clay bodies, and pay closer attention to cones. Also, figure out the over reduction on the right side. It might be that one burner that sounds a bit off.

Kakewake CG bowls
Kakewake CG bowls
guinomi, need more sand in the clay
guinomi, need more sand in the clay
crystals, only grew on the right side, where reduction was strongest.
crystals, only grew on the right side, where reduction was strongest.
cylindrical tea bowls
cylindrical tea bowls
yunomi
yunomi
shells on feet
shells on feet

IMG_3437

saggared and much improved.
saggared and much improved.
porcelain, saggared
porcelain, saggared

IMG_3464 IMG_3463 IMG_3462 IMG_3460 IMG_3459

 

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 Open Studio

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

Chosen Karatsu Slabs

I had to make a batch of slab plates after the fall wood kiln firing, because every one of my slabs cracked in that firing. Turns out the clay I used was high in silica, and didn’t agree with the long wood kiln firing. The silica turned into cristabolite, and all pots made with that clay experienced shivering, or cracking, no matter what glaze they were paired with, and across a range of temperatures.

Forward a few weeks, and I’m frantically trying to get some replacement plates fired because this weekend is the fall open studio event, followed by an exhibition in Nagasaki during the first week of Dec.

For the most part this firing went well, aside from the fact that I exploded my large platter. Drat.

Rainy Season Is Here

A lot has happened over the last month since the Karatsu pottery festival, mostly cleaning, shelf building, and shifting things around in the studio in preparation for the open studio event which happened this last weekend from June 19th to June 21st.

In rough chronological order, here is what has happened in May:

Plates formed over wood slabs of various sizes

Paddled slab plates en masse...
Paddled slab plates en masse…

We got our garden planted and our first Jalapenos soon followed!

This year's small Jalapeno crop. Not many, but it's a start.
This year’s small Jalapeno crop. Not many, but it’s a start.

Another type of crop: Good batch of Madara Karatsu guinomi from late April firing. Body is mostly crushed sandstone with a bit of native low iron clay to help keep things together.

Madara Karatsu guinomi from spring gas firing.
Madara Karatsu guinomi from spring gas firing.

In prep for the open studio event, I cleaned the deck and brickwork of the backyard. I did not realize just how overgrown with algae and moss it had become until it was clean again.

The deck and bricks after being power washed. Almost like a new backyard.
The deck and bricks after being power washed. Almost like a new backyard.

One of the worst sections, but it felt really cathartic blasting all of that green away, leaving nice clean trails of clear, brown wood.

Before After pic of the deck, what a difference!
Before After pic of the deck, what a difference!

Entrance to the yard event space, tents and blue tarps up to  keep out the rain. Luckily, although it threatened a few times, it never really rained, and the last day was actually sunny and hot. This is  the middle of monsoon season folks, we totally lucked out.

Emeth and Shimauchi san's burgers. Best burgers in Nagasaki. Best burgers in Saga for 3 days only.
Emeth and Shimauchi san’s burgers. Best burgers in Nagasaki. Best burgers in Saga for 3 days only.

The spot for gamblers. 500 yen per turn, no losers. One grand prize, 15 second place prizes, 25 3rd place prizes, and 100 4th place prizes. One grand prize went out every single day of the 3 day event. Happy customers!

Pot lottery wheel. No losers here, everyone walks away with a pot, some better than others...
Pot lottery wheel. No losers here, everyone walks away with a pot, some better than others…

This discount table was a new strategy for me. Turned out to be great for turning older pots into cash and additional storage space in my studio showroom.

My discount table, holding everything I haven't sold in 6 years that I couldn't bear to hammer. I think about 300 of these pots found new homes.
My discount table, holding everything I haven’t sold in 6 years that I couldn’t bear to hammer. I think about 300 of these pots found new homes.

Knife and tool maker, really nice stuff for reasonable prices

Knives and tools from Matsubara forge, in Nagasaki.
Knives and tools from Matsubara forge, in Nagasaki.

Really big caterpillar!

A friend I discovered during the open studio event. Never seen one like this before.
A friend I discovered during the open studio event. Never seen one like this before.

My favorite studio tool…

….is without a doubt the Peter Pugger de-airing pugger/mixer. Until two years ago I did all of my clay and stone mixing in a large deep platter by hand, and it was killing my wrists.  Hearing all the wonderful things Peter Pugger had to say on their website, I took the plunge and decided to spend the money and save my hands. I figured if the thing worked half as well as it was supposed to, I would be ok.

Well, it is now about 2 years since I got it and it does everything it is reputed to do, and does it very well. My wrists are now pain free, and I have saved hundreds of hours of time processing and blending clay bodies.

Blending wet clay bodies usually takes about 15 minutes of mixing, but mostly I mix dry materials with water (sometimes blending into wet bodies), and this takes a while longer, usually around 30 minutes.

In my work, keeping the character of the wild clay is of utmost importance, and I’ve found that de-airing generally kills that character dead. However, the de-airing is necessary in getting the water to penetrate the dry materials more quickly, so that I don’t have to let the pugged clay sit for a month before using.

My solution to this is to let the clay mix, then I de-air it once completely, followed by re-mixing the batch for 5 – 10 minutes after reintroducing air. This gives me clay that is not as easy to throw, but which gives very nice trimmed texture.

Here are some pictures of some clay from the other day which I collected from the mountain behind my home. I added the dry/damp clumps of clay to the hopper (removing as many large rocks as I could find), then water, then mixed. I repeated these three steps until the hopper was full, then mixed for about 20 minutes, turned on the vacuum pump, and de-aired completely.

Next I went to lunch.  It was yummy. It was sunny on the deck and there was a cool breeze. The neighbors have a  great cherry tree in full bloom and the wind was blowing the petals off, and they were fluttering across the yard like giant pink snowflakes. I noticed as I saw some of them fall across the deck that the wisteria was budding out and even starting to show some purple. Nice. I imagine the wisteria will be in full bloom a few weeks early this year.

After coming back to the studio, I re-introduced air to the mixing chamber and mixed some more, then pugged it all out and made some pots. The whole process took about 2 hours. It takes even less time if you decide not to include lunch, but I recommend including it.