Heat Work Problem

On Tue, 14 Oct 2003 19:31:14 -0400, Tom Buck wrote:

Just recently I programed a controller for a new kiln, Cone 6 Oxidation,
1240/60 oC, and set cone packs on every shelf. this tallish electric had a
"cool" bottom, "hot" top... variations: 2 cones. so I programmed in a
"lag" and lowered the heat rate from 150 oC/hour to 100 oC/h after we
passed 573 oC. result: more uniform firing and pots properly fired to
maturity and not overfired.
if you do not push the heat input too high, the pyro and the
controller will come closer to meshing.

Hello,

Sorry if I make some mistakes, I'm French and my English is not
perfect.

For the Pete's problem, I would say as Tom : maybe the firing is too
quick at the end. I begin to fire myself and I learn. But in my
school, we made some firings.
For the glaze, with a gas kiln, we went quite quickly at the
beginning, 350°C/h until 1000°C. But after, we went slower, 80°C/h.
About 1100°C, the glaze begin to melt and if you go too quickly, the
temperature is not homogeneous in the kiln and you will have
differences. In an another firing we made, also in a gas kiln, we went
very quickly (all the firing last 5 hours), went a little higher than
1280°C and just made a little soak at the end (about 5 mn if I
remember weel). The result : the glaze wasn't the same in different
places in the kiln. I made blue bowls, five were at the bottom, one
was at the top. The firts were bleu, the last was green...

I don't know if you can use the same speed in a electric kiln than a
gas kiln. The maker of the one I have since two days told me not to
reach 1000°C in less than 7 h, to protect bricks from too fast
wear....

Corinne
Beurdine #1, MLB#1, ....#1
Pour me répondre, faites moi descendre de ma moto