Richard Mahaffey on mon 24 jul 06
Mel, Richard,
I think that as the pyrometer is a tool, so to is the computer
controller on an electric kiln. We fire our bisques on computers. We
program it each time depending on the load, it's wetness, the thickness
of the work, the density of the load.
I have not given control to the computer, but it allows me greater
control. I can control the kiln to rise slowly while I sleep (a good
thing for a teacher, because we get soooo crabby when we are at school
turning up a bisque instead of sleeping) or hold or even drop. I find
that the timer on our old kilns with switches, kiln sitter and timer
moves only a fraction of the number of hours, when the computer does
it's thing according to the program that I enter, when compared with the
old time manual turn the switches.
I agree if you just use the bisque program that is supplied with some
controllers you have given control to someone else. You are stuck with
someone else's compromizes and assumption. Glaze calculation software
is the same, some else's compromizes and assumptions.
I would say that the temperature that you bisque to has more to do with
craftsmanship than does turning up the kiln manually.
BTW, a pyrometer shows temperature but cones show heat work that is the
effect of the heat over time on the materials you ware and glazes are
made from. Another way to think of it is that the pyrometer show a
thumbnail shot and the cones show the whole picture.
YMMV, ;-)
Rick Mahaffey
Lee Love on tue 25 jul 06
On 7/24/06, Richard Mahaffey wrote:
>
> BTW, a pyrometer shows temperature but cones show heat work that is the
> effect of the heat over time on the materials you ware and glazes are
> made from. Another way to think of it is that the pyrometer show a
> thumbnail shot and the cones show the whole picture.
Actually, ;^), (and not to quibble), but cones don't always show "the
whole picture." I think Hank mentioned while we were firing, that
woodfire will reduce the cone reading by one cone and vapor glazing by
another cone.
The best indication of the state of the glaze at any moment in
time are test tiles. At my teacher's workshop, pulled tiles always
had the final say on weither the firing was finished or not.
Just bought 20kgs of shino clay. It is called Mogusa tsuchi.
I pay 800yen for 15kgs for my Mashiko clay, but this clay costs
4800yen for 20kg. Just testing, but probably will only use it with my
shino type glaze on tea related ware. It is very open. will mix it
with Mashiko clay.
.
--
Lee in Mashiko, Japan
http://potters.blogspot.com/
"Let the beauty we love be what we do." - Rumi
Hank Murrow on tue 25 jul 06
On Jul 25, 2006, at 2:59 AM, Lee Love wrote:
> Just bought 20kgs of shino clay. It is called Mogusa tsuchi.
> I pay 800yen for 15kgs for my Mashiko clay, but this clay costs
> 4800yen for 20kg. Just testing, but probably will only use it with my
> shino type glaze on tea related ware. It is very open. will mix it
> with Mashiko clay.
Dear Lee;
Also try it by itself. The Tea folks prefer the 'open' clay for chawan
because the whisk makes a sound like 'rain on thatch' rather than the
'rain on a tin roof' sound that comes with vitrification. True shino
clays from tajimi vitrify around cone 15_16. Shigemasa Higashida gave
us 'chapter and verse' on this point when we visited him in his Tokyo
studio.
Cheers, Hank
www.murrow.biz/hank
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