Front came out beautifully, mid stack as well, rear a little cool. Very top of front, mid, and rear were cold. Shelf config caused this, I think, because of the large shelves being close together, creating strata in the heat gradient. The very front shelf with guinomi and chawan was the main culprit, blocking the flame from rising, and directing it under the large shelves placed midway up the front stack.
In the future I need to stagger the shelf levels during stacking, to allow the flame to travel upward. Also, block some of the floor level flue channels at the rear of the chamber. Make sure upper flues are fully open.
Warning: some Shino enthusiasts may find content in this post offensive and/or snarky.
When I was in Korea this last October, the subject of Shino came up. Shino, like Raku, Chawan, and Geisha, tends to have a different set of meanings and expectations, depending on who you are talking to (usually Japanese vs non-Japanese).
Most Shino enthusiasts in Japan get their pantaloons in a twist when they see this smooth orange, white, or carbon trapping glaze that most Americans call Shino. “Sore wa Shino janai” is a common thing to hear when showing off your American Shino to a Japanese Shino lover.
In Japan, Shino is a combination of clay, glaze, and firing method. The definition is somewhat cramped , and leaves little wiggle room. Same with Raku, Chawan, and Geisha. There is all this history and tradition hanging on at the end of the label, foiling our attempts to add new dimensions to the term.
Here’s the problem: The Shino purists are vastly outnumbered. Actually, I’m one of them (to a degree) but acknowledge that on the worldwide level, Shino means more to a whole lot of world potters and enthusiasts. I really wish the word had not been co-opted by English, but it has, so oh well…
Embracing this trend, I have decided to widen the definition of Shino even further. Here are some examples:
(I do make a ‘Shino’ glaze, but do not call it Shino for fear of reprisal.)
This is one way I make slab plates. I posted the pictures to FB but am reposting here with descriptions of each step. You can adjust the steps if your clay is more or less forgiving than mine.
First cut slabs and let them rest overnight to stiffen up some. These slabs are 10mm thick.
Trim the slab with an undercut bevel, and save the trimmed edges.
Sprinkle something on your form to prevent the clay from sticking. I use corn starch.
Place the trimmed slab bevel side down on your form and paddle it THOROUGHLY, from center to edge, then once more evenly all over. You can use whatever you want as a paddle, here I used a sandbag, but I usually use a wooden paddle.
Place the trimmed edges you saved back on the paddled slab, followed by a paper towel or other cloth, and your board. Turn over the form to release the slab onto the board.
Press the center of the slab down gently and let the edge pieces support the edge of the plate. While supporting the edge with one hand, use the other to define a concavity in the bevel with a convex tool. Anything convex and with a curve you like will work. I used a little ball here. Sometimes I use a rib, sometimes a roller, sometimes a clamshell. I like rollers and balls because they compress the edge well.
Finish and further compress the edge with a damp (not wet) chamois or sponge. Done!
Fired with cones 6,7,8 on top and bottom shelves. Pyrometer at middle shelf, didn’t display over 1215C.
Hotter on bottom than top. By cone, looks like cone 9+ on the bottom, cone 9 at the middle, and cone 8+ at the top.
Reduction strong at top shelf, weaker at middle and bottom.
There is an old story around here about Nakazato Muan (12th Generation Nakazato Tarouemon, Living National Treasure) finding a really great white clay seam in the Azambaru area of Taku. Here it is in Japanese for those of you who can read it:
For those of you whose Japanese is a bit rusty, it goes like this:
In the year Showa 21 (1946), the Nakazato kiln was converted from a coal burning kiln to a wood burning kiln, and it was fired until Showa 25 (1950). During this time, Muan mostly used a white clay from the Azanbaru area of Taku. There is a story, told by his son Shigetoshi, from the day they discovered this clay seam (Nakazato Shigetoshi passed away in 2015, at the age of 85, so he was probably around 16 years old at the time of this story).
So they have all this clay loaded onto a cart, which Shigetoshi is pulling and his father Muan is pushing, to Taku train station.
On the way, they reach a downward slope, and without noticing, Muan keeps pushing down the slope, and they almost run into a car speeding down the road. Shigetoshi ends up diving to avoid the car, the car ends up in a rice field, and their cart ends up broken. When Shigetoshi gets angry and starts yelling, Muan says “I was so busy thinking about what I was going to make with this clay, I didn’t notice the slope.”, apologizing to Shigetoshi.
“That was the first time my father ever apologized to me.”, Shigetoshi commented.
So why, you say, are you telling me all of this? Well, the fabled white clay seam has been looked for now by other potters for decades with no luck, but due to a fortuitous event a few months ago (and several years of looking), I believe I have found it again. Here are some pictures from our excursion out to dig some sample material for testing.
Oh, and lastly, here’s a picture of one of Nakazato Muan’s coil and paddle built jars. This one is made from white clay from the clay seam pictured above. My firing tests have almost the same color as the unglazed bottom section of this jar (although it is hard to see from this dark picture).
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: