sacredclay on sat 28 jul 07
I might finally join the ranks of being called old school, but I was
taught that when one load a kiln for bisquing, or even firing, one does
not put the greenware close to the elements. One leaves at least an
inch space all around the kiln withing the walls. Yet,twice, I've came
across pixs of people who have their pieces snuggles up against the
wall and my mind is screaming "It's gonna melt!" Yet, there's reports
of it being fine after. What gives? Kathryn Hughes in NC
Jim Willett on sun 29 jul 07
On Sat, 28 Jul 2007 02:02:00 -0000, sacredclay
wrote:
>I might finally join the ranks of being called old school, but I was
>taught that when one load a kiln for bisquing, or even firing, one does
>not put the greenware close to the elements. One leaves at least an
>inch space all around the kiln withing the walls. Yet,twice, I've came
>across pixs of people who have their pieces snuggles up against the
>wall and my mind is screaming "It's gonna melt!" Yet, there's reports
>of it being fine after. What gives? Kathryn Hughes in NC
Hi Kathryn,
As always the following is just the way we do it, not the way everyone
else does or should do it. Over the close to forty years of using electric
kilns for bisquing and firing in our experience the biggest rule has been
don't let anything touch the element. That is the quickest way to burn out
an element and of course kill the piece. We load bisque against the walls
all the time and have noticed no difference in the final result. The main
thing is to allow some air circulation around each piece, allow some
soaking time,and of course don't touch the elements. With glaze loads the
rules obviously change because you'll wind up glazing your pot to the wall
or another pot...we've done that too and it's definitely not a good thing!
Regards,
Jim and Cindy
Out of the Fire Studio
Edmonton, Alberta
http://www.outofthefirestudio.com
Donna Kat on sun 29 jul 07
On Sat, 28 Jul 2007 02:02:00 -0000, sacredclay
wrote:
>I might finally join the ranks of being called old school, but I was
>taught that when one load a kiln for bisquing, or even firing, one does
>not put the greenware close to the elements. One leaves at least an
>inch space all around the kiln withing the walls. Yet,twice, I've came
>across pixs of people who have their pieces snuggles up against the
>wall and my mind is screaming "It's gonna melt!" Yet, there's reports
>of it being fine after. What gives? Kathryn Hughes in NC
JMO but I don't think your bisqueware is going to melt. At least I have
never heard of that happening. What you are doing, I believe, in giving
the inch clearance is protecting your elements. You don't want chemicals
which gas out from the clay covering the elements. Donna
Jim Willett on mon 30 jul 07
On Mon, 30 Jul 2007 00:07:35 -0500, Jason Zw. wrote:
....... "I was taught as a general rule to try to keep the pieces packed
close in the middle levels and lighter loads at the top and bottom levels.
Although the heat is projected from the wall in, it helps to think of the
best heat work area as a within a giant egg shape in the the kiln...center
and light on the bottom, wide and heavy around the middle then back to
centered and light at the top"...........
This is why most new kilns have three zones and use three thermocouples.
Each zone will heat as required to keep the heat even inside. As a result we
have found you can load a bisque kiln quite heavily, leaning pieces against
the wall as required,avoiding contact with the elements,allowing air space
around and between each item, and with a properly ramped firing schedule and
a soak at the end get consistent results. Both our ten and sixteen cu ft
kilns have been fired several hundred times without replacing an element in
either so I would tend to think there is not too much to worry about.
Regards,
Jim
http://www.outofthefirestudio.com
Jason Zw. on mon 30 jul 07
Yes, definitely away from the elements for the elements sake. Anything close
to the elements that will absorb the heat energy will cause that element and
the relay to work harder then needed and expire before its time. I was
taught as a general rule to try to keep the pieces packed close in the
middle levels and lighter loads at the top and bottom levels. Although the
heat is projected from the wall in, it helps to think of the best heat work
area as a within a giant egg shape in the the kiln...center and light on the
bottom, wide and heavy around the middle then back to centered and light at
the top. Always take in to consideration the thicknesses of the pieces and
place the thicker ones on the middle levels.
Arnold Howard on tue 31 jul 07
From: "sacredclay"
Yet,twice, I've came
across pixs of people who have their pieces snuggles up
against the
wall and my mind is screaming "It's gonna melt!"
-------------
I, too, agree with keeping the ware 1" away from the heating
elements. It's okay to place ware closer to a section of
wall that is between element rows.
Sometimes a camera angle makes a piece of ware look like it
is right up against the element when actually it is not.
I've dealt with this problem myself when taking pictures.
Sincerely,
Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
ahoward@paragonweb.com / www.paragonweb.com
sacredclay on wed 1 aug 07
-Jim, Three thermocouples??? when did they started putting that in the
kilns? I really do need to look around more often and not just at my
wheel! Warmly, Kathryn Hughes in NC
> This is why most new kilns have three zones and use three
thermocouples.
>
> Each zone will heat as required to keep the heat even inside. As a
result we
> have found you can load a bisque kiln quite heavily, leaning pieces
against
>>
> Regards,
>
> Jim
>
Jim Willett on wed 1 aug 07
On Wed, 1 Aug 2007 07:36:11 -0500, Arnold Howard
wrote:
>Three-zone has been available for about seven years on the
>Bartlett and Orton controllers. That feature is built into
>the controllers used on the larger kilns (not the little
>table-top models).
>
>Though three-zone is available, it seems that most people
>prefer single-zone. There is less to go wrong. And the
>typical electric kiln heats evenly with only one
>thermocouple.
>
Both our kilns, a ten cubic foot Coneart and a sixteen cubic foot Coneart
have Bartlett controllers with three zones, and with these kilns I have to
disagree that they fire evenly enough to be able to run single zone. We
know from observing hundreds of firings that the only way to get a
consistent, repeatable, result in the entire kiln is to have the three
zones. You can watch and hear as the top and bottom fire more frequently
and longer to match the center zone. We run with a five degree lag and as
we fire time and temperature to a specific ramp up and down schedule
rather than a "cone" setting there is no way a single zone kiln would do
it for us unless we stilted the bottom shelf up a few inches and also
didn't load too close to the top. It would be interesting to hear from a
few other people firing electric kilns and see if their experience matches
ours.
Jim Willett, Cindy Clarke
Out of the Fire Studio
Edmonton
http://www.outofthefirestudio.com
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