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electric kiln mystery and using kiln sitters

updated wed 21 nov 07

 

Marni Turkel on fri 16 nov 07


Hank has addressed this point before that kiln sitters are there to
turn the kiln off when it reaches temperature. You can set a higher
cone in it than your computer or visual cones and use it as a back up
if you want.

I want to emphasize that the statement below by Wayne is not
universally shared. I realize that Wayne is going off line for
awhile, so this is directed to others on the list who might take his
statement to mean that if you use a kiln sitter to turn off your kiln
then you are doing something wrong or aren't using your brain. You
are just doing it a little differently than he does.

Does it really matter if you use your eyes to see when there has been
enough heat work to bend a witness cone or you use an incredibly
simple and elegant solution (a kiln sitter) to do this for you when
the cone bends? The studio where I first worked had 2 kilns, one had
a kiln sitter the other just had an on-off switch; I was taught to
look for red heat on a bisque and then turned it off. I have always
fired electric. Before controllers, if I wanted to soak a firing at
maximum temperature, I had to be there when it reached temperature
and then restart it, turn it to medium for a period of time and then
wait to turn it off. Was I more of a potter then than I am now that I
just program it in?

I've done thousands of firings using the kiln sitter to turn off the
kiln and had very consistent firings. I switched to computer
controllers because of differences from top to bottom not from firing
to firing.

I once sat in a lecture on Japanese mingei (folk art) pottery where
the lecturer (referring to the use of witness cones) said: "Real
potters don't use cones." He believed it, I didn't.

In the end, I'll be dead and people will just judge the pots.



At 12:00 AM -0500 11/17/07, Wayne Seidl wrote:
>The kiln
>sitter is not there to replace YOUR BRAIN. It is there to assist,
>_in_case_ there is a problem.

--
Marni


Marni Turkel
2080 Llano Rd 1B
Santa Rosa, CA 95407
Phone 707-579-5567
Fax 707-579-1116

Stony Point Ceramic Design & Orchids
http://www.marniturkel.com

Sonoma Urn Company
http://www.sonomaurn.com

William & Susan Schran User on sat 17 nov 07


On 11/17/07 1:23 AM, "Marni Turkel" wrote:

> Does it really matter if you use your eyes to see when there has been
> enough heat work to bend a witness cone or you use an incredibly
> simple and elegant solution (a kiln sitter) to do this for you when
> the cone bends? The studio where I first worked had 2 kilns, one had
> a kiln sitter the other just had an on-off switch; I was taught to
> look for red heat on a bisque and then turned it off. I have always
> fired electric. Before controllers, if I wanted to soak a firing at
> maximum temperature, I had to be there when it reached temperature
> and then restart it, turn it to medium for a period of time and then
> wait to turn it off. Was I more of a potter then than I am now that I
> just program it in?

Much of what you say will make sense to those who wish to rely on a
mechanical or electrical device to decide when a firing is completed.
But when something goes wrong, as it will, they are left with trying to
figure out what went wrong and exactly how hot the kiln got. Witness cones
will help to provide a record of that information. The Kilnsitter is a nice
simple device that can easily get out of adjustment and/or parts deteriorate
over time. Assuming it will always provide you with the same accurate
information, well, you're just fooling yourself. Those that leave a
Kilnsitter to turn the kiln off and come back the next morning are simply
courting disaster.

Had a friend, good potter, would fire his bisque just looking at red heat &
pyrometer. When he started having problems with glaze blisters/pinholing I
asked him what cone was his bisque firing. He responded he didn't use or
need cones. Told him to use cones next couple of bisque firings. Next glaze
firing he didn't have anymore glaze issues.

I fire a manual electric with Kilnsitter and a programmable kiln in my
studio. I use and fire with cones, ALWAYS. At school we have manual &
programmable electrics and gas fired kilns. Cones are ALWAYS used in every
firing.

Cones, simple & elegant...


--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com

Marni Turkel on sun 18 nov 07


Bill,

I agree completely with you that having witness cones in a firing is
really valuable, because that is the only way to really know what
heat work is occurring and where. Thermocouples drift over time and a
kiln sitter only measures the heat work one spot in the kiln. Before
I had controllers, I chose to let the cone in the kiln sitter
determine when there was enough heat work to bend the cone and drop
the lever to shut off the power. After the firing I would use the
witness cones to monitor any changes from firing to firing. You can
adjust a kiln sitter with a surprising degree of accuracy and also
change the placement of the cone in the kiln sitter to fine tune it
further. The consistency from firing to firing was amazingly good, I
added the controllers to increase the consistency from zone to zone
in a kiln and do controlled the cooling rather than to improve the
consistency from firing to firing.

I have 3 witness cones in each firing, one for each zone. Besides
using a computer controller and a kiln sitter (with a cone 1 cone
higher that I am firing), I also use a timer. Still, something can
always go wrong. Rather than firing a big kiln every month or so, I
prefer smaller ones more frequently where if I loose a load, it won't
break me.

I was responding to the following statement which I understood to
mean that if you used a kiln sitter to shut off your kiln you weren't
doing it right.

> ....not by treating the kiln sitter as some sort of automatic shut
>off switch. The kiln
>sitter is not there to replace YOUR BRAIN. It is there to assist,
>_in_case_ there is a problem.

The point I wanted to make (perhaps I didn't do it very well) is that
there are many ways to deal with firing and that one is not
necessarily right and another one wrong, they are choices. Back-ups
and safe guards are very important, know your equipment and keep
records from firing to firing to detect changes.

My quote of the "Real potters don't use cones" was not meant to imply
one shouldn't use cones. When I first heard the comment, I thought
the lecturer was kidding, but it became apparent very quickly that he
was dead serious. For him this was an "new technology" that should be
considered a crutch. If you took advantage of it, you were less of a
potter. Whether it is cones or kiln sitters, I don't agree.
--
Marni


Marni Turkel
2080 Llano Rd 1B
Santa Rosa, CA 95407
Phone 707-579-5567
Fax 707-579-1116

Stony Point Ceramic Design & Orchids
http://www.marniturkel.com

Sonoma Urn Company
http://www.sonomaurn.com

WJ Seidl on mon 19 nov 07


Marni:
That comment: "...not treating the kiln sitter...etc." was mine. What I
MEANT was that you should not be using it instead of your brain, but
rather, in addition to. The point, of course, being that if one is
relying on machinery, it can/will eventually fail. And does...with
alarming regularity.
I did not mean to imply that by using the sitter, you were not doing it
right.
My apologies for any confusion.
Best,
Wayne Seidl

Marni Turkel wrote:
> Bill,
>
> I agree completely with you that having witness cones in a firing is
> really valuable, because that is the only way to really know what
> heat work is occurring and where. Thermocouples drift over time and a
> kiln sitter only measures the heat work one spot in the kiln. Before
> I had controllers, I chose to let the cone in the kiln sitter
> determine when there was enough heat work to bend the cone and drop
> the lever to shut off the power. After the firing I would use the
> witness cones to monitor any changes from firing to firing. You can
> adjust a kiln sitter with a surprising degree of accuracy and also
> change the placement of the cone in the kiln sitter to fine tune it
> further. The consistency from firing to firing was amazingly good, I
> added the controllers to increase the consistency from zone to zone
> in a kiln and do controlled the cooling rather than to improve the
> consistency from firing to firing.
>
> I have 3 witness cones in each firing, one for each zone. Besides
> using a computer controller and a kiln sitter (with a cone 1 cone
> higher that I am firing), I also use a timer. Still, something can
> always go wrong. Rather than firing a big kiln every month or so, I
> prefer smaller ones more frequently where if I loose a load, it won't
> break me.
>
> I was responding to the following statement which I understood to
> mean that if you used a kiln sitter to shut off your kiln you weren't
> doing it right.
>
>> ....not by treating the kiln sitter as some sort of automatic shut
>> off switch. The kiln
>> sitter is not there to replace YOUR BRAIN. It is there to assist,
>> _in_case_ there is a problem.
>
> The point I wanted to make (perhaps I didn't do it very well) is that
> there are many ways to deal with firing and that one is not
> necessarily right and another one wrong, they are choices. Back-ups
> and safe guards are very important, know your equipment and keep
> records from firing to firing to detect changes.
>
> My quote of the "Real potters don't use cones" was not meant to imply
> one shouldn't use cones. When I first heard the comment, I thought
> the lecturer was kidding, but it became apparent very quickly that he
> was dead serious. For him this was an "new technology" that should be
> considered a crutch. If you took advantage of it, you were less of a
> potter. Whether it is cones or kiln sitters, I don't agree.
> --
> Marni
>
>
> Marni Turkel
> 2080 Llano Rd 1B
> Santa Rosa, CA 95407
> Phone 707-579-5567
> Fax 707-579-1116
>
> Stony Point Ceramic Design & Orchids
> http://www.marniturkel.com
>
> Sonoma Urn Company
> http://www.sonomaurn.com
>
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Ron Roy on mon 19 nov 07


I agree with Bill - what can go wrong will go wrong - Kiln sitters are not
to be trusted - be there at the end of a firing or pay the price
eventually.

Had a blow up in a bisque kiln when I was teaching - a bit of the clay from
the explosion got under the rod - held it up - if we had not been there to
turn the kiln off - might have burned down the school.

RR


>I fire a manual electric with Kilnsitter and a programmable kiln in my
>studio. I use and fire with cones, ALWAYS. At school we have manual &
>programmable electrics and gas fired kilns. Cones are ALWAYS used in every
>firing.
>
>Cones, simple & elegant...
>
>
>--
>William "Bill" Schran

Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0