MARK JOYCE on thu 6 feb 97
ClayArters --
This summer I will be teaching a five-day Clay in the Classroom
residency for classroom teachers. I will need to be able to dry
pieces within 24 hours.
Several years ago I participated in a weeklong summer residency
at Alfred and and they had a heated drying cabinet that enabled us to
do such turnarounds. I believe that the heat element was on the
bottom and there may have been a small fan drawing air out the top. I
don't remember the heat source but I don't think it was electric.
I think the shelves were that stiff extruded diamond-shaped mesh.
Circulation was great!
Do any of you know of sources for such a box/cabinet? Have any of you
built one by insulting and recycling some other kind of cabinet and
outfitting it with a heat lamp and small exhaust fan?
At this point, I have time to explore the possibilities...
Surely, someone has been this way before me!
Ideas? Thoughts? Caveats?
Thanks!
Mark Joyce joycem@caa.edu Concordia College Ann Arbor, MI
Darcy on fri 7 feb 97
The hot box at Alfred has an electric kiln element set in softbrick on the
floor. It is somewhat buried in greenware shards and debris, so I could
see how it could be overlooked. The size of the hot box is large enough
that the element is always glowing to maintain temperature.
Randy O'Brien
dln8@cornell.edu
>----------------------------Original message----------------------------
>
>Several years ago I participated in a weeklong summer residency
>at Alfred and and they had a heated drying cabinet that enabled us to
>do such turnarounds. I believe that the heat element was on the
>bottom and there may have been a small fan drawing air out the top. I
>don't remember the heat source but I don't think it was electric.
>I think the shelves were that stiff extruded diamond-shaped mesh.
>Circulation was great!
>
>Do any of you know of sources for such a box/cabinet? Have any of you
>built one by insulting and recycling some other kind of cabinet and
>outfitting it with a heat lamp and small exhaust fan?
>
>
>Mark Joyce joycem@caa.edu Concordia College Ann Arbor, MI
Tom Buck on sat 8 feb 97
Mark Joyce: You might consider using old top of range heating units
(calrod) but connecting ghem to 120 volts rather than 240 V (the usual)
this in effect cuts the wattage from say 1200 to 300, which probably is
enough for a fast drying box, a framed box/door sheathed in say gyproc or
similar wallboard (non-combiustible).
Cheers TomB Hamilton ON Canada URL http://digitalfire.com/magic/tombuck.htm
Margaret Arial on sun 9 feb 97
What would be a good starting point for designing a hotbox for drying tile
that would not cause them to warp?Here in South Carolina midlands the summer
humidity is unreal and higher than a lot of places the rest of the year and
drying is painfully slow (nic for the skin though).
Bill Aycock on mon 10 feb 97
At 11:54 AM 2/9/97 EST, you wrote:
>----------------------------Original message----------------------------
>What would be a good starting point for designing a hotbox for drying tile
>that would not cause them to warp?Here in South Carolina midlands the summer
>humidity is unreal and higher than a lot of places the rest of the year and
>drying is painfully slow (nic for the skin though).
>
Margaret- the really surprising thing about a drying cabinet with regard to
warping and cracking is that you need to keep the humidity in the cabinet
UP, not down. The first drying cabinet I ever saw was at Penland (also in
one of the Carolinas), and it had pans of water on the heater, with pieces
of broken plaster bats sticking up from the water to act as wicks.
I know the pieces dried there came out in great shape, and fast. I have seen
an explanation here, that went into detail about the changes in water
viscosity with heat, which had to do with how fast the water would travel.
I'm only a retired Rocket scientist (as in "it doesn't take a---"), so I
cant give you an absolute explanation, but-----IT WORKS.
Bill, pondering the state of the universe, on Persimmon Hill.
Bill Aycock --- Persimmon Hill --- Woodville, Alabama, USA
--- (in the N.E. corner of the State)
also-- W4BSG -- Grid EM64vr
Dave and Pat Eitel on tue 11 feb 97
>----------------------------Original message----------------------------
Bill Aycock wrote:
>Margaret- the really surprising thing about a drying cabinet with regard to
>warping and cracking is that you need to keep the humidity in the cabinet
>UP, not down. The first drying cabinet I ever saw was at Penland (also in
>one of the Carolinas), and it had pans of water on the heater, with pieces
>of broken plaster bats sticking up from the water to act as wicks.
>
>I know the pieces dried there came out in great shape, and fast. I have seen
>an explanation here, that went into detail about the changes in water
>viscosity with heat, which had to do with how fast the water would travel.
>I'm only a retired Rocket scientist (as in "it doesn't take a---"), so I
>cant give you an absolute explanation, but-----IT WORKS.
My 2 cents' worth is that I,too, first saw a drybox at Penland, but either
there were not pans of water, etc, at those times, or I just didn't see
them. I've been there several times and never seen the water pans. So,
when I designed my drybox there are no pans or other humidity source.
There are 3 350 watt lightbulbs in the bottom and enough cracks all around
the box to permit air circulation. The box works great on everything
except plates, a few of which have cracked over the years. But I can put
freshly handled mugs in there at 5 pm and bisque them at 8 the next
morning. No cracks or warps. I couldn't get along without my drybox.
Later...Dave
Dave Eitel
Cedar Creek Pottery
Cedarburg, WI
pots@cedarcreekpottery.com
http://www.cedarcreekpottery.com
Margaret Arial on wed 12 feb 97
Dear Bill,
I have been to Penland numerous sessions but the drying cabinet as you
describe it either changed or I just didn't pay attention to its
construction.Does this arrangement use any special elements or a ground fault
circuit breaker? Is there a fan involved and where is it located?Any advice?
Margaret
Bill Aycock on thu 13 feb 97
At 09:16 AM 2/12/97 EST, you wrote:
>----------------------------Original message----------------------------
>Dear Bill,
>I have been to Penland numerous sessions but the drying cabinet as you
>describe it either changed or I just didn't pay attention to its
>construction.Does this arrangement use any special elements or a ground fault
>circuit breaker? Is there a fan involved and where is it located?Any advice?
>Margaret
>
Margaret- Let me confess something- the session I was in when I saw the one
I described was in 1965. The current studio assistant, who set up the
cabinet, was just out of an extended session with Margaret Wildenhain. He
may have picked up the idea there. He used the cabinet as part of a rapid
process and sequence he used to make MANY teapots in a day. He never had a
drying crack.
As always at Penland, change is the order. I would not be surprised if that
cabinet was completely changed before the next spring.
Today, I would certainly use a GFI, as I would, (and do) for any circuit
near water. The original cabinet had no fan, and, really, was rather
primitive; just a closed box, tall, with places for shelves. The heater was
a simple hot plate, sitting on a busted shelf
The theory, as I remember it from discussions here, has two main parts.
First, the heat makes the viscosity of the water drop, which allows it to
move through the clay faster. Second, the elevated water content of the air
prevents the surface from drying too fast. This also has two effects; it
prevents the surface shrinking too fast, which both prevents stress and lets
the water flow out of the piece faster. This keeps the internal water
content more uniform, which prevents warping.
This all could be wrong, but it is what I read, and heard, and it seems to work.
Bill Aycock --- Persimmon Hill --- Woodville, Alabama, USA
--- (in the N.E. corner of the State)
also-- W4BSG -- Grid EM64vr
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