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over-fire (was electric kilns & brownouts)

updated wed 16 aug 00

 

Arnold Howard on tue 15 aug 00


I am sorry to read about Gail's over-fire with her Paragon controller and the
lack of support she received. (See below.) That would disappoint anyone.

I've always believed that one should not fully trust the controller, or the
Kiln Sitter. These are mechanical devices that can fail when you least expect
it.

Suggestions:

1. Each time you load the kiln, be sure the thermocouple (temperature sensor)
is protruding into the firing chamber. (The Paragon thermocouple should
protrude 1/2" - 5/8". Other brands may vary.)

2. Use witness cones. Check the kiln occasionally during firing, even though
the kiln is automatic.

3. Keep firing records so that you will know the expected shut-off time for
each type of firing. Thus you will be alerted if the kiln fires longer than
usual. Check the kiln near the expected shut-off time.

4. Learn to judge temperature by the color of the firing chamber. If you
can't see the witness cones, you can still estimate temperature.

5. Be sure you have not inadvertently programmed a hold. Double-check with
program review before firing. An extended hold can over-fire the ware.

Because the electronic controller is reliable and does so many amazing
things, it is only natural to trust it. But I agree with Gail...you shouldn't
trust it completely.

If anyone else has suggestions about over-fire prevention, please share them.

With best wishes,

Arnold Howard
Paragon Industries, Inc.

--- BTu1690922@AOL.COM wrote:
> To Joyce,
> do you by chance have a Paragon with digital controller? I had a bad
> experience, overfired the kiln, got no support or acknowledgement of any
> responsibility from Paragon at that time. All my kiln shelves bowed, which
> was why I couldnt see the cones. So I relied on the controller, which was
> way later replaced at no cost when I called a different person there. No
> problems now, it had to be that controller. So it cost me a set of kiln
> shelves and all my work, left my new kiln bricks with cracks. I am still
> unhappy about the whole thing, have been firing electric kilns over 20
> years,
> and have never had this type of situation before. I don't trust the
> controller now, wish I had a kilnsitter instead. So sorry to hear you had
> a
> bad experience too.
> Gail
> Gilchrist, Tx


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