Beth Wyatt on thu 8 feb 07
Hi Clay Art people
I have questions regarding the same cracking pattern I have now found
in the bricks of two electric kilns, mine & a friend's:
We both fire/cool very slowly, she, to cone 10, and I, to cone 02.
Neither of us have any additional support under the kiln bottom. I
purchased my Crucible kiln with a pre-installed Orton vent before the
little leg extending to the floor was standard.
She has a side positioned vent on a Cress kiln.
During my last three firings, either a self-supporting cone..or
worse...one of my taller vessels, was knocked over, indicating quite
a bit of very unwanted movement!
We have identical cracking on both the lid and the bottom of our
kilns. This did not happen with my previous, non- vented electric
kiln, which I fired for over 6 years to cone 8. What is happening
here? Is it the venting? The lack of additional bottom support?
And...what is the best remedy?
Thanks! to any & all info!
Arnold Howard on tue 13 feb 07
From: "Beth Wyatt"
> purchased my Crucible kiln with a pre-installed Orton vent
> before the
> little leg extending to the floor was standard.
> She has a side positioned vent on a Cress kiln.
> During my last three firings, either a self-supporting
> cone..or
> worse...one of my taller vessels, was knocked over,
> indicating quite
> a bit of very unwanted movement!
> We have identical cracking on both the lid and the bottom
> of our
> kilns.
Beth, I have never heard of a downdraft vent causing the
firebricks to crack. I don't know why that would happen.
The following can cause the vent to vibrate:
1) The kiln is not level.
2) Dirt has collected in the squirrel cage.
3) Moisture has corroded the squirrel cage unevenly,
throwing it out of balance.
Orton sells a gasket that reduces vibration from the motor.
The gasket fits between the vent and kiln.
To make the vent last longer, regularly vacuum the kiln
interior and the floor under the kiln.
Sincerely,
Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
ahoward@paragonweb.com / www.paragonweb.com
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