Craig Edwards on sat 15 feb 97
------------------
Hello=3B
I=22m in the process of making some plaster bats for drying out reclaim =
before I
run it through the pugmill.
I've built some wooden frames that are 3=2A18=2A18, with no bottom in them =
so I can
put the reclaim in between them.
The idea of inbedding heat tape in the plaster is something that I have =
heard
of but never done. Is there anyone out there that has experience in putting =
heat
tape in drying bats. TIA
Enjoying a sunny Feb. day in Minnesota,
Craig
Dennis H. Davis on sun 16 feb 97
At 11:50 AM 2/15/97 EST, you wrote:
>----------------------------Original message----------------------------
>I"m in the process of making some plaster bats for drying out reclaim .....
Is there anyone out there that has experience in putting heat tape in
drying bats. TIA
--------------------------------------------------------------------------
I sat down at the computer tonight to send out the same question. Glad I
read my incoming mail first. For the past 6 weeks I have been working on
putting together a new pottery facility for The Art League School in
Alexandria, VA. We have a nice size room for the pugmill, recycle buckets
and drying bats. My thought was that the heat was most important in drying
out the bat between uses so that we could reprocess almost continuously. In
our former classroom we were reprocessing so much clay that it was a great
inconvenience to leave the bat empty and wait for it to dry out. But using
a damp bat increased the time required to dry successive batches.
My first thought was to use the heat strips for wrapping water pipes in cold
spaces or to use outdoor gutter heaters. However, I thought that might not
work because the thermostats for those items are set to turn on near
freezing temperature (a local supplier, Dominion Electric Supply confirmed
that). I then asked them about the matting imbedded in slabs for heating.
They were very hesitant to give me much information (mention of U.L., etc)
until I convinced them that casting the matting in plaster of paris would be
similar to imbedding in concrete. When they finally agreed to talk
specifics, the cost proved to be prohibitive - 4.5 square feet of matting
for $115.00 and one thermostat for $150.75 (and I wanted to make at least
two of them).
Today, I was thinking about imbedding water pipe and using a small water
heater and pump to periodically pass warm water through the bat.
If anyone has successfully made a heated drying bat, I too really would
appreciate receiving details.
Dennis
In Stafford, VA
Donald G. Goldsobel on mon 17 feb 97
At 11:43 AM 2/16/97 EST, you wrote:
>----------------------------Original message----------------------------
>At 11:50 AM 2/15/97 EST, you wrote:
>>----------------------------Original message----------------------------
>>I"m in the process of making some plaster bats for drying out reclaim .....
> Is there anyone out there that has experience in putting heat tape in
>drying bats. TIA
>--------------------------------------------------------------------------
>how nabout setting a heating element used in reptile cages in sand and
setting the bats on the sand. OR- use a mounted hot air blower OR an engine
heating blanket used to keep engine blocks from freezing in Minnesota
conditions???
>
Darcy on mon 17 feb 97
An alternative to heating a plaster bat to speed up drying would be using
the ram press mold idea of casting an air hose in the plaster. I have done
this and although it won't return the plaster to a bone dry state, it will
pump a huge amount of water out of a saturated bat. I always thought this
would be a great demo for students to show how incredibly porous plaster
is. Another advantage would be that the plaster will last longer since you
are removing soluble materials with the water and not leaving them in the
plaster if allowed to evaporate.
I once had the brilliant idea to warm my bagged clay up in the winter by
sticking a dipstick oil heater into the center of the bag. I plugged it in
and within three minutes the center of the clay had boiled off all moisture
leaving a crunchy core. The rest of the clay was as cold as when I
started. So I can't help but wonder if the plaster around the heat source
might dry out completely and then be susceptible to destruction from the
heat?
As for instructions on the air hose idea, get some clear plastic tubing
from the hardware store (10 feet or so for a 2' x3' bat) and fit it with a
quick connect compressor coupling. Put a piece of wire down the length of
the tube so it will stay where you want it when you cast it. Cut notches
in the tube every 1/2" or so, wrap it with a strip of cloth (an old sheet
works great) so it doesn't fill up with plaster when you cast it and then
spiral it throughout the bat. Also, plug the end of the tube sticking out
of the plaster while you cast it. Otherwise it acts as a filter and water
will run out when you fill the mold with plaster.
Randy O'Brien
dln8@cornell.edu
>>----------------------------Original message----------------------------
>If anyone has successfully made a heated drying bat, I too really would
>appreciate receiving details.
>
>Dennis
>In Stafford, VA
sam wainford on mon 17 feb 97
Dennis H. Davis wrote:
>
> ----------------------------Original message----------------------------
> At 11:50 AM 2/15/97 EST, you wrote:
> >----------------------------Original message----------------------------
> >I"m in the process of making some plaster bats for drying out reclaim .....
> Is there anyone out there that has experience in putting heat tape in
> drying bats. TIA
> --------------------------------------------------------------------------
>
> I sat down at the computer tonight to send out the same question. Glad I
> read my incoming mail first. For the past 6 weeks I have been working on
> putting together a new pottery facility for The Art League School in
> Alexandria, VA. We have a nice size room for the pugmill, recycle buckets
> and drying bats. My thought was that the heat was most important in drying
> out the bat between uses so that we could reprocess almost continuously. In
> our former classroom we were reprocessing so much clay that it was a great
> inconvenience to leave the bat empty and wait for it to dry out. But using
> a damp bat increased the time required to dry successive batches.
>
> My first thought was to use the heat strips for wrapping water pipes in cold
> spaces or to use outdoor gutter heaters. However, I thought that might not
> work because the thermostats for those items are set to turn on near
> freezing temperature (a local supplier, Dominion Electric Supply confirmed
> that). I then asked them about the matting imbedded in slabs for heating.
> They were very hesitant to give me much information (mention of U.L., etc)
> until I convinced them that casting the matting in plaster of paris would be
> similar to imbedding in concrete. When they finally agreed to talk
> specifics, the cost proved to be prohibitive - 4.5 square feet of matting
> for $115.00 and one thermostat for $150.75 (and I wanted to make at least
> two of them).
>
> Today, I was thinking about imbedding water pipe and using a small water
> heater and pump to periodically pass warm water through the bat.
>
> If anyone has successfully made a heated drying bat, I too really would
> appreciate receiving details.
>
> Dennis
> In Stafford, VA
Hi Dennis and all,
I'm following this discussion with great interest since I make ALL my
clay by the slip method, then pug it. My drying bats are more like big
rectangular plaster bowls(cast from two different sized plastic tubs,
one inside the other and pouring the plaster in between). I pour about
10 lbs. of clay slip in each. It seems to help having the slip in
contact with the plaster sides as well as the bottom, although the clay
pulls away from the sides as it dries. I built carts for my plaster
tubs so I can pull them around the studio or out into the sun. I used
two treated 2 x 4's on edge for the cart frame so air can circulate as
much as possible beneath the plaster bats(tubs). Just having a fan
blowing seems to help a lot. Here in south Georgia, we have extremely
high humidity and drying anything can be painfully slow. I am all ears
on this subject, and would appreciate any and all suggestions on
heating/drying the bats. Thanks, Sam
BobWicks@aol.com on mon 17 feb 97
H Dennis:
I have been thinking about using heat tapes in my bats also and dabble in
electronics as I am a ham radio operator. I read somewhere that this has
been done before. To use the heat tape just remove the thermostat from the
heat tape. There will be two connections on it. Then all you have to do is
to get a used room thermostat (cheaper) and install it in the exact position
as the one you just removed from the heat tape and you should be in business.
Then all you have to do is to adjust the temperature as you would the if you
were controlling the room temperature. I'm confident that this will do a
fine job for you. Be sure that your joints are well insulated so that water
will not short them out. I have been going to try this out for some time but
never got around to doing it. You want to remember that if you turn the heat
up too high that it will deaden the plaster and it will no long absorb water.
This may not be a great concern as the temperature would have to be well
over 200 degrees. Just stay within the room temperature range and you'll
have no trouble.
I would be very interested in how you make out on this project, so let me
hear from you.
Bobwicks@aol.com W3HAH
Craig Edwards on tue 18 feb 97
----------------------------Original message----------------------------
An alternative to heating a plaster bat to speed up drying would be using
the ram press mold idea of casting an air hose in the plaster. I have done
this and although it won't return the plaster to a bone dry state, it will
pump a huge amount of water out of a saturated bat. I always thought this
would be a great demo for students to show how incredibly porous plaster
is. Another advantage would be that the plaster will last longer since you
are removing soluble materials with the water and not leaving them in the
plaster if allowed to evaporate.
As for instructions on the air hose idea, get some clear plastic tubing
from the hardware store (10 feet or so for a 2' x3' bat) and fit it with a
quick connect compressor coupling. Put a piece of wire down the length of
the tube so it will stay where you want it when you cast it. Cut notches
in the tube every 1/2=22 or so, wrap it with a strip of cloth (an old sheet
works great) so it doesn't fill up with plaster when you cast it and then
spiral it throughout the bat. Also, plug the end of the tube sticking out
of the plaster while you cast it. Otherwise it acts as a filter and water
will run out when you fill the mold with plaster.
Randy: thanks for the input. After going round and round about keeping bats =
dry for reclaim and receiving alot of good input your idea seems to fit my =
situation. Being that my studio is equiped with two ram
presses, fiting the bats with air release is no problem. We use Ceramical or=
Densite K-40, for ram molds. I have never ran a purge schedule for Number 1=
Pottery Plaster or USG regular. With Ceramical after the
plaster is poured it must heat up 23 degrees before you can start purging =
the water out. Is there a Schedule for Number 1 or USG regular. Again thanks=
for all the great input
Regards,
Craig Edwards
Marget and Peter Lippincott on tue 18 feb 97
Dennis H. Davis wrote:
>
> ----------------------------Original message----------------------------
> At 11:50 AM 2/15/97 EST, you wrote:
> >----------------------------Original message----------------------------
> >I"m in the process of making some plaster bats for drying out reclaim .....
> Is there anyone out there that has experience in putting heat tape in
> drying bats. TIA
> --------------------------------------------------------------------------
>
> I sat down at the computer tonight to send out the same question. Glad I
> read my incoming mail first. For the past 6 weeks I have been working on
> putting together a new pottery facility for The Art League School in
> Alexandria, VA. We have a nice size room for the pugmill, recycle buckets
> and drying bats. My thought was that the heat was most important in drying
> out the bat between uses so that we could reprocess almost continuously. In
> our former classroom we were reprocessing so much clay that it was a great
> inconvenience to leave the bat empty and wait for it to dry out. But using
> a damp bat increased the time required to dry successive batches.
>
> My first thought was to use the heat strips for wrapping water pipes in cold
> spaces or to use outdoor gutter heaters. However, I thought that might not
> work because the thermostats for those items are set to turn on near
> freezing temperature (a local supplier, Dominion Electric Supply confirmed
> that). I then asked them about the matting imbedded in slabs for heating.
> They were very hesitant to give me much information (mention of U.L., etc)
> until I convinced them that casting the matting in plaster of paris would be
> similar to imbedding in concrete. When they finally agreed to talk
> specifics, the cost proved to be prohibitive - 4.5 square feet of matting
> for $115.00 and one thermostat for $150.75 (and I wanted to make at least
> two of them).
>
> Today, I was thinking about imbedding water pipe and using a small water
> heater and pump to periodically pass warm water through the bat.
>
> If anyone has successfully made a heated drying bat, I too really would
> appreciate receiving details.
>
> Dennis
> In Stafford, VA
Dennis:
What about heat tapes used for the edges of roofs and gutters in
northern climes. If I recall correctly, they are not thermostated; one
just plugs them in and they go. I do not know how much heat (what
temperature they would achieve) when encapsulated in plaster. It may be
too much. Plaster cannot be heated as high as concrete me thinks. If
force drying fresh plaster I think that one does not want to exceed 140
degrees F. What about a drying bin for plaster bats with or without
their load of wet clay similar to a drying bin for pots. There has been
a thread on this recently. A heat source (small elec heater, big light
bulb...) at the bottom and a small equimpent cooling fan at the top to
keep an air flow going bottom to top might do the trick. If you just
used this to dry the bats, theyn could be on edge and get a lot of
flowby of warm air. If horizontal they should not be the same side as
the cabinet or there willl be no flow. What do youthink?
Peter Lippincott
Mudpuppy Pottery
Dennis H. Davis on wed 19 feb 97
Thanks for the continued interest in my problem. Couldn't help but go out
this morning and check out the reptile cage heating pads. I think they
might work but like the floor heating mats w/thermostat would be fairly
expensive. A mat approximately 8x16 inches was $55. Perhaps 3-4 would be
required for each 3x4 foot bat? And I still think heat source needs to be
cast into the bat - not sure about being able to do that with these mats.
Am waiting for a catalog from a waterbed wholesaler and considering waterbed
heaters which have a heat source and thermostat in water, obviously
waterproof. An external control lets you raise/lower the temperature within
a range which is comfortable to the sleeper (maybe clay too). More later on
this.
Keith: I did save the posting on American Science and Surplus but
am having trouble getting through to their voice mailbox (always full).
Perhaps it is time to learn how to use my FAX modem. The seed germination
tapes/mats mighht work but I wonder about the 70 degree temp. I sure wish I
knew what temperature the heat source should be inside the bats.
Peter: Elecric heaters, heat bulbs and fans were where I started,
but immediately felt I wanted to get the heat source inside for more even
drying. Perhaps my approach is too Hi-Tech.
Still, I have a good feeling about the waterbed heater.
Dennis
In Stafford, VA
Hluch - Kevin A. on wed 19 feb 97
Claude Conover, now deceased, was the first person I know of who used
electric heating mulching wires embedded in plaster to keep the plaster
bat (18"by 4ft) continuously dry...Worked like a charm.
Kevin A. Hluch
102 E. 8th St.
Frederick, MD 21701
USA
On Sun, 16 Feb 1997, Dennis H. Davis wrote:
> ----------------------------Original message----------------------------
> At 11:50 AM 2/15/97 EST, you wrote:
> >----------------------------Original message----------------------------
> >I"m in the process of making some plaster bats for drying out reclaim .....
> Is there anyone out there that has experience in putting heat tape in
> drying bats. TIA
> --------------------------------------------------------------------------
>
> I sat down at the computer tonight to send out the same question. Glad I
> read my incoming mail first. For the past 6 weeks I have been working on
> putting together a new pottery facility for The Art League School in
> Alexandria, VA. We have a nice size room for the pugmill, recycle buckets
> and drying bats. My thought was that the heat was most important in drying
> out the bat between uses so that we could reprocess almost continuously. In
> our former classroom we were reprocessing so much clay that it was a great
> inconvenience to leave the bat empty and wait for it to dry out. But using
> a damp bat increased the time required to dry successive batches.
>
> My first thought was to use the heat strips for wrapping water pipes in cold
> spaces or to use outdoor gutter heaters. However, I thought that might not
> work because the thermostats for those items are set to turn on near
> freezing temperature (a local supplier, Dominion Electric Supply confirmed
> that). I then asked them about the matting imbedded in slabs for heating.
> They were very hesitant to give me much information (mention of U.L., etc)
> until I convinced them that casting the matting in plaster of paris would be
> similar to imbedding in concrete. When they finally agreed to talk
> specifics, the cost proved to be prohibitive - 4.5 square feet of matting
> for $115.00 and one thermostat for $150.75 (and I wanted to make at least
> two of them).
>
> Today, I was thinking about imbedding water pipe and using a small water
> heater and pump to periodically pass warm water through the bat.
>
> If anyone has successfully made a heated drying bat, I too really would
> appreciate receiving details.
>
> Dennis
> In Stafford, VA
>
Margaret Arial on thu 20 feb 97
I have purchased heating wire that is thermosthatically controlled for
starting seedlings from greenhouse supplyhouses which can be found by
searching "gardening" on aol.I have not used it myself for bats but it runs
in the 10-15 dollar range for a goodly length.It is used in trays .Margaret
Fay & Ralph Loewenthal on thu 20 feb 97
Instead of using plaster to reclaim we use canvass.
There is a problem with plaster in that when the plaster
starts to crumble or chip then it can land up in your
clay with some rather nasty results. The plaster is also
very heavy and is difficult to move. We store our wheel
cleanings and trimmings in a drum / trash can and
cover with water. When we have filled the drum then
we put the clay on to pieces of canvass to let it dry
out to the consistency that we can pug or wedge it.
This process has worked very well for us. We lay the
canvass on the floor, but I imagine one could suspend
it and have a fan blowing air over it to dry out the clay
faster and more evenly.
Ralph in a lovely sunny Port Elizabeth
John Guerin on fri 21 feb 97
In a message dated 97-02-20 07:38:18 EST, fayralph@sprintlink.co.za (Fay &
Ralph Loewenthal) writes:
<< nstead of using plaster to reclaim we use canvass.
There is a problem with plaster in that when the plaster
starts to crumble or chip then it can land up in your
clay with some rather nasty results. The plaster is also
very heavy and is difficult to move. We store our wheel
cleanings and trimmings in a drum / trash can and
cover with water. When we have filled the drum then
we put the clay on to pieces of canvass to let it dry
out to the consistency that we can pug or wedge it.
This process has worked very well for us. We lay the
canvass on the floor, but I imagine one could suspend
it and have a fan blowing air over it to dry out the clay
faster and more evenly.
Ralph in a lovely sunny Port Elizabeth >>
Native americans do the same thing to remove excess water from clay when they
are processing local 'found' clay. Except they place the canvas ( or old
cotton sheet) directly on the ground. Here in the southwest, the sandy soil
speeds up the drying process by by drawing the water down through the
canvas/cloth into the ground. Sometimes they also pour the mixtue into a
cloth flour sack, tie the end and set the sack on the sandy soil and let the
water drain out. This takes a little longer than spreading the mixture out
over a larger area like a sheet of canvas or old cotton sheet, but works well
if you don't have an large open space available. (a pillow case will do if
you don't have a cloth flour sack) Place the pillow case inside a large
plastic pail, pour the mixture in, tie it and then lift it out and set it on
the ground. If you don't have any ground to set it on (this is for you city
slickers), hang it up and set a bucket under it to catch the water.
John Guerin
Indian Pottery Instructor
Tucson,AZ
Pearl Joseph on fri 21 feb 97
Dennis;
Waterbed heaters are not in water. They are under the mattress that holds the
water, and if I remember correctly, the heater is under a plastic liner that
the mattress sits in.
Pearl Joseph in White Plains, NY
Dennis H. Davis on mon 3 mar 97
Thanks to all who communicated with me on the reclaim bats. I have decided
to go with waterbed heaters cast in the bottom of the bats (for easy removal
in case this doesn't work). We will cast the bats in about a week and after
we use them for a few weeks, I will post information on how they are working.
I checked out the heating strips used for seed beds but found the
thermostats are set for 74 degrees, not enough difference from room
temperature to dry the bats.
Dennis Davis
P.O. Box 483
Stafford, VA 22555
Paul Monaghan on tue 4 mar 97
Dennis H. Davis wrote:
>
> ----------------------------Original message----------------------------
> Thanks to all who communicated with me on the reclaim bats. I have decided
> to go with waterbed heaters cast in the bottom of the bats (for easy removal
> in case this doesn't work). We will cast the bats in about a week and after
> we use them for a few weeks, I will post information on how they are working.
>
> I checked out the heating strips used for seed beds but found the
> thermostats are set for 74 degrees, not enough difference from room
> temperature to dry the bats.
> Dennis Davis
> P.O. Box 483
> Stafford, VA 22555
Dennis,
I would check this carefully before casting the heaters into the bats.
These heaters ar designed to have a very large thermal sink - the large
water bag - and my overheat and burn out very quickly.
Paul
--
Paul J. Monaghan email: paul@web2u.com
WEB2U Productions --- http://www.web2u.com
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