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itc and temmoku

updated tue 30 sep 97

 

Vince Pitelka on tue 9 sep 97

>As an after thought - I saw a teapot of Liz Willoughby's in a show with a
>beautiful black temnoku glaze on one side and a boring brown on the other
>side. I asked Liz how this happened. She said the black side was facing
>the back wall of her newly sprayed kiln. This lead me to believe in the
>reflective qualities of ITC 100. It also made me puzzle over how to have
>the reflective thing happen throughout the kiln. Saggars, maybe? I opted
>for spraying the shelves.
>Let's see what everyone else has to say.
>Keep firing and keep being forward thinking.
>Long may your chimney smoke!
>Sheila and Tony Clennell

I don't think it had anything to do with the ITC, except possibly that the
kiln wall absorbed less heat during the firing due to the ITC coating. In
either case, after glaze reduction, when the kiln was shut off, the kiln
wall caused that side of the pot to cool quickly, preventing it from
re-oxidizing to brown. The side of the pot facing the inside of the kiln
cooled more slowly, and reoxidized. Apparently the glaze was applied quite
thinly, because in a normal reduction firing and cooling, temmokus usually
remain black only where thicker. Maybe Ron Roy will offer an opinion on this.
- Vince

Vince Pitelka - vpitelka@DeKalb.net
Home 615/597-5376, work 615/597-6801, fax 615/597-6803
Appalachian Center for Crafts
1560 Craft Center Drive, Smithville TN 37166

Clennell on wed 10 sep 97

>
>I don't think it had anything to do with the ITC, except possibly that the
>kiln wall absorbed less heat during the firing due to the ITC coating. In
>either case, after glaze reduction, when the kiln was shut off, the kiln
>wall caused that side of the pot to cool quickly, preventing it from
>re-oxidizing to brown. The side of the pot facing the inside of the kiln
>cooled more slowly, and reoxidized. Apparently the glaze was applied quite
>thinly, because in a normal reduction firing and cooling, temmokus usually
>remain black only where thicker. Maybe Ron Roy will offer an opinion on this.
>- Vince
>
>Vince Pitelka - vpitelka@DeKalb.net
>Home 615/597-5376, work 615/597-6801, fax 615/597-6803
>Appalachian Center for Crafts
>1560 Craft Center Drive, Smithville TN 37166

Dear Vince:ITC is my theory and I'm stickin' with it until the ole guy
sings. First of all Liz is a close friend of the grandfather of temmoku
in Canada. Ron Roy works with Liz at Tucker's and between Ron and Liz they
would have the specific gravity of Liz's temmoku bang on the money.
Besides thin temnoku is never black it's brown. Liz was a nurse before she
went to pot and she is meticulous, meticulous , meticulous. I have seen
oxidized temmoku and it doesn't look at all like thin temmoku. If you had
seen the teapot it was like it had been dipped in brown on one side and a
beautie of a temmoku on the other.
I do agree that temmoku galazes favour fast cooling but I can't see the pot
being that much cooler inches from the wall.
I hope you all have an answer soon, because I don't want to think about
temmoku too much. It never sells and you're forever dusting it .Give me a
good old snot green ash glaze anyday!
Cheers,
Tony


Sheila and Tony Clennell
Gleason Brook Pottery
Box l0, RR#2,
Wiarton, Ontario
NOH 2TO
Canada

Phone # 1 (519) 534-2935
Fax # 1 (519) 534-0602
E-mail clennell@bmts.com

Liz Willoughby on wed 10 sep 97

> O.K guys, Thought that I should jump in here to clarify a couple of
>things. I had been having difficulty getting good reduction in the top
>back of my kiln. (I've since solved that problem), but I did have a few
>pieces of tenmoku on that shelf. The only one that had that rich black
>tenmoku in that area was that teapot on that side (next to the back wall).
>Don't really think that it was a too thin application of glaze. All the
>others just in that area were also oxidized. Also the iron rich clay that
>I use to place my cones in were oxidized. I use Porcelain, and use the
>stoneware for cones to gauge my body reduction. I'm really at a loss,
>because I don't `really' understand why that pot was blacker on the ITC
>side. It must have got hotter, because of the reflective quality of ITC,
>but why would that cause the glaze to be more reduced? Would be curious
>if anyone else had any input on why this happened. Liz


----------------------------Original message----------------------------
>>As an after thought - I saw a teapot of Liz Willoughby's in a show with a
>>beautiful black temnoku glaze on one side and a boring brown on the other
>>side. I asked Liz how this happened. She said the black side was facing
>>the back wall of her newly sprayed kiln. This lead me to believe in the
>>reflective qualities of ITC 100. It also made me puzzle over how to have
>>the reflective thing happen throughout the kiln. Saggars, maybe? I opted
>>for spraying the shelves.
>>Let's see what everyone else has to say.
>>Keep firing and keep being forward thinking.
>>Long may your chimney smoke!
>>Sheila and Tony Clennell
>
>I don't think it had anything to do with the ITC, except possibly that the
>kiln wall absorbed less heat during the firing due to the ITC coating. In
>either case, after glaze reduction, when the kiln was shut off, the kiln
>wall caused that side of the pot to cool quickly, preventing it from
>re-oxidizing to brown. The side of the pot facing the inside of the kiln
>cooled more slowly, and reoxidized. Apparently the glaze was applied quite
>thinly, because in a normal reduction firing and cooling, temmokus usually
>remain black only where thicker. Maybe Ron Roy will offer an opinion on this.
>- Vince
>
>Vince Pitelka - vpitelka@DeKalb.net
>Home 615/597-5376, work 615/597-6801, fax 615/597-6803
>Appalachian Center for Crafts
>1560 Craft Center Drive, Smithville TN 37166

Liz Willoughby
R.R. 1
Grafton, Ontario
K0K 2G0
e-mail lizwill@cyberion.ca