William Q Hynes on wed 22 jul 98
Hi everyone! First, I want to send out hearty thanks to those who replied
to my Raku Glaze post! I tried a lot of the glazes out and for the first
time: I was enthralled with fabulous colors! Thanks!!! :)
Secondly, I have been running the bisque kiln here at the university for
about a year. I was given basic instruction as to loading and how to take
the kiln through the bisque (which is an L&L model, which is "cranked" up
a notch on the hour every hour). I was interested in more info than what
was given to me. For example, maybe you guys could enlighten my
experiences with explanations as to how you bisque fire, load, etc...any
info would be great! I'd appreciate your help once again!!! Thank you!
cookie
(who's using her ceramics professor's e-mail account:
wqhyne@ark.ship.edu)
thanks again!
Cindy on thu 23 jul 98
Cookie,
I'm sure you'll get lots of responses on this one, and not certain my 2
cents will be worth a lot to you with the kiln you're using, but here goes.
;> I load as dry a ware as possible--usually to protect the kiln elements
rather than to protect the ware. It is not unthinkable to fire ware still
wet from the wheel so long as it has thin walls and a small flat surface
(bottom). I would not fire platters or anything else with a large flat
surface unless it was unquestionably bone dry. I try to stagger the shelves
to promote even heat flow throughout the kiln. At the very least, I leave
an appreciable crack between shelves which have been placed at the same
height.
My kiln has a computer controller, so I program it to take the ware up to
210 degrees F at 200/hr. I then program it to hold there. For larger
pieces, I may hold as much as 6 hours (for very large pieces). For a load
consisting entirely of smaller ware, I will hold for 1 hour, just to give
the ware time to get rid of all un-bound water.
Once the hold time is finished, I fire at 150 F/hr up to 500 F. At 500 F, I
am told, the chemically bound water will be exhausted. I don't program a
hold time at 500 F. After this phase, I set the kiln to fire up to 1940 F
at 275 F/hr. It works well for me.
I have a hard time bisque firing large ware in my old kiln. It heats up way
to fast, even with only one element turned on. If I have to use it for
bisquing large pieces, I leave the lid completely open, perhaps for half a
day or more, with one element turned on. Then I close the lid, keeping it
cracked open on the highest notch for several hours before closing it
completely. Next morning, I peek to see if the pot is whole, then start the
second element. After several hours with two elements, it is usually safe
to fire quickly. If I don't do this, it can break pieces which have set out
in the sun for days, been placed on top of the large kiln during several
firings, and are, I *know* as dry as I could possibly get them.
For bisque-firing smaller, thin-walled pottery, the small kiln works fine.
I just keep it on one switch for 3-4 hours, then 2 overnight, and close all
the remaining switches in the morning.
Cindy Strnad
Earthen Vessels
Custer, SD
USA http://blackhills-info.com/a/cindys/menu.htm
----------
> From: William Q Hynes
> To: CLAYART@LSV.UKY.EDU
> Subject: Background on Bisquing
> Date: Wednesday, July 22, 1998 7:37 AM
>
> Hi everyone! First, I want to send out hearty thanks to those who
replied
> to my Raku Glaze post! I tried a lot of the glazes out and for the first
> time: I was enthralled with fabulous colors! Thanks!!! :)
>
> Secondly, I have been running the bisque kiln here at the university for
> about a year. I was given basic instruction as to loading and how to
take
> the kiln through the bisque (which is an L&L model, which is "cranked" up
> a notch on the hour every hour). I was interested in more info than what
> was given to me. For example, maybe you guys could enlighten my
> experiences with explanations as to how you bisque fire, load, etc...any
> info would be great! I'd appreciate your help once again!!! Thank you!
>
> cookie
>
> (who's using her ceramics professor's e-mail account:
> wqhyne@ark.ship.edu)
>
> thanks again!
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