Anthony Allison on sun 22 nov 98
Greetings from the North (15 degrees this morning) BRrrrrrrr
My question is this. I used to think that a pot dried from the top down
because there was more air up at top contacting the inside and the outside
of the pot simultaneously whereas the bottom and the lower portion had less
surface area to dry it out. Here's the thing- I made some lidded pieces with
deeply cut feet and with the lid on. There is pretty even air surface area
but the pots still dried from top down. What gives? Is this simply a
function of throwing where the cross section is somewhat thicker towards the
bottom?
Torpid Brain in Minnesota
Tony
The Brinks on mon 23 nov 98
I always assumed GRAVITY (water runs downhill) was the reason!
Ann Brink
At 07:12 PM 11/22/98 EST, you wrote:
>----------------------------Original message----------------------------
>Greetings from the North (15 degrees this morning) BRrrrrrrr
>
>My question is this. I used to think that a pot dried from the top down
>because there was more air up at top contacting the inside and the outside
>of the pot simultaneously whereas the bottom and the lower portion had less
>surface area to dry it out. Here's the thing- I made some lidded pieces with
>deeply cut feet and with the lid on. There is pretty even air surface area
>but the pots still dried from top down. What gives? Is this simply a
>function of throwing where the cross section is somewhat thicker towards the
>bottom?
>
>Torpid Brain in Minnesota
>
>Tony
>
>
e-mail billann@impulse.net
Vince Pitelka on mon 23 nov 98
>My question is this. I used to think that a pot dried from the top down
>because there was more air up at top contacting the inside and the outside
>of the pot simultaneously whereas the bottom and the lower portion had less
>surface area to dry it out. Here's the thing- I made some lidded pieces with
>deeply cut feet and with the lid on. There is pretty even air surface area
>but the pots still dried from top down. What gives? Is this simply a
>function of throwing where the cross section is somewhat thicker towards the
>bottom?
Tony -
OK, here's a guess, but I think it's a pretty good one. You know about
evaporative cooling? When water evaporates from a surface, it absorbs
energy to transform the water from liquid to gas, and cools the surface and
the immediately surrounding air. Cool air is heavier, and therefore will
sink. So, aside from other drafts within the room, the cool moist air will
pass down over the surface of the pot, drawing warmer, drier air in at the
top. So, in almost any circumstance, the top will dry first, even if it is
a lidded jar with lid on, or if the upper walls are thicker.
- Vince
Vince Pitelka - vpitelka@DeKalb.net
Home 615/597-5376, work 615/597-6801, fax 615/597-6803
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Elizabeth Swann on mon 23 nov 98
Hi I'm not sure how to help pots from drying top to bottom but the
reason they do is because the top of the pot gets more circulating air
then the base. Air gets trapped in the pot and stays humid.
Sometimes putting a plastic bag over top of the piece and graduly
removing it helps kept drying a little more even
Liz Vancouver
(It's nice weather here.)
>Date: Sun, 22 Nov 1998 19:12:59 EST
>Reply-To: Ceramic Arts Discussion List
>From: Anthony Allison
>Subject: Drying Clay
>To: CLAYART@LSV.UKY.EDU
>
>----------------------------Original
message----------------------------
>Greetings from the North (15 degrees this morning) BRrrrrrrr
>
>My question is this. I used to think that a pot dried from the top down
>because there was more air up at top contacting the inside and the
outside
>of the pot simultaneously whereas the bottom and the lower portion had
less
>surface area to dry it out. Here's the thing- I made some lidded pieces
with
>deeply cut feet and with the lid on. There is pretty even air surface
area
>but the pots still dried from top down. What gives? Is this simply a
>function of throwing where the cross section is somewhat thicker
towards the
>bottom?
>
>Torpid Brain in Minnesota
>
>Tony
>
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
Andi Runt on tue 24 nov 98
Hi Tony,
I think the water content of the pot is affected by gravity-as is
everything on the face of the earth. Even in my very tight wet-box, the
moisture gravitates toward the rims when I invert my pots. No (observable)
drying is taking place, just re-distribution.
Andi in PA
Andi Runt
Impressions in Pottery
State College, PA
jpri@email. psu.edu
D. Kim Lindaberry on tue 24 nov 98
> ----------------------------Original message----------------------------
> >My question is this. I used to think that a pot dried from the top down
> >because there was more air up at top contacting the inside and the outside
> >of the pot simultaneously whereas the bottom and the lower portion had less
> >surface area to dry it out. Here's the thing- I made some lidded pieces with
> >deeply cut feet and with the lid on. There is pretty even air surface area
> >but the pots still dried from top down. What gives?
I don't have any answers, but from reading the posts I have thought of
an "experiment" one might try to help answer this question. How about
throwing a cylinder or two. Trim them and then leave then upside down to
dry. In this case will the pot still dry from top (upper most part of
the cylinder in it's inverted position) to bottom (the lip) or vice
versa?
just my two cents worth
cheers
Kim
--
D. Kim Lindaberry
Longview Community College
500 SW Longview Road
Art Department
Lee's Summit, MO 64108
USA
to visit my web site go to:
http://www.kcmetro.cc.mo.us/longview/humanities/art/kiml/
to send e-mail to me use: mailto:kiml@kcmetro.cc.mo.us
Stephen Mills on thu 26 nov 98
If one portion of a pot is sat on a shelf it doesn't have as much air
circulating round it as the "top" bit, so dries slower!
If I'm in a hurry I set freshly thrown pieces on a piece of very
absorbant insulating board (won't have plaster in my workshop) then the
top & bottom dry at the same speed.
Steve
Bath
UK
>> ----------------------------Original message----------------------------
>> >My question is this. I used to think that a pot dried from the top down
>> >because there was more air up at top contacting the inside and the outside
>> >of the pot simultaneously whereas the bottom and the lower portion had less
>> >surface area to dry it out. Here's the thing- I made some lidded pieces with
>> >deeply cut feet and with the lid on. There is pretty even air surface area
>> >but the pots still dried from top down. What gives?
>
>I don't have any answers, but from reading the posts I have thought of
>an "experiment" one might try to help answer this question. How about
>throwing a cylinder or two. Trim them and then leave then upside down to
>dry. In this case will the pot still dry from top (upper most part of
>the cylinder in it's inverted position) to bottom (the lip) or vice
>versa?
>
>just my two cents worth
>
>cheers
>
>Kim
>
>
>--
>D. Kim Lindaberry
>Longview Community College
>500 SW Longview Road
>Art Department
>Lee's Summit, MO 64108
>USA
>
>to visit my web site go to:
>http://www.kcmetro.cc.mo.us/longview/humanities/art/kiml/
>to send e-mail to me use: mailto:kiml@kcmetro.cc.mo.us
>
--
Steve Mills
Bath
UK
home e-mail: stevemills@mudslinger.demon.co.uk
work e-mail: stevemills@bathpotters.demon.co.uk
own website: http://www.mudslinger.demon.co.uk
BPS website: http://www.bathpotters.demon.co.uk
Milton Markey on wed 2 dec 98
Hi fellow clay-driers!
One way I avoid the problem presented on this thread, is to invert the pot
once the pot is sufficiently "leather hard." I then restore the pot to it's
intended upright position once the bottom has hardened sufficiently.
This method works well with my candle holders, which have holes poked through
on the walls. It may work well with bowls and other pots with intact walls,
too.
Milton MiltonsLin@AOL.COM
Andi Runt on wed 2 dec 98
Steve,
What kind of "very absorbant insulating board" that isn't plaster? What's
it called?
-------------------------Original message----------------------------
>If one portion of a pot is sat on a shelf it doesn't have as much air
>circulating round it as the "top" bit, so dries slower!
>If I'm in a hurry I set freshly thrown pieces on a piece of very
>absorbant insulating board (won't have plaster in my workshop) then the
>top & bottom dry at the same speed.
>
>Steve
>Bath
>UK
>
>
>
>>> ----------------------------Original message----------------------------
>>> >My question is this. I used to think that a pot dried from the top down
>>> >because there was more air up at top contacting the inside and the outside
>>> >of the pot simultaneously whereas the bottom and the lower portion had
>>>less
>>> >surface area to dry it out. Here's the thing- I made some lidded
>>>pieces with
>>> >deeply cut feet and with the lid on. There is pretty even air surface area
>>> >but the pots still dried from top down. What gives?
>>
>>I don't have any answers, but from reading the posts I have thought of
>>an "experiment" one might try to help answer this question. How about
>>throwing a cylinder or two. Trim them and then leave then upside down to
>>dry. In this case will the pot still dry from top (upper most part of
>>the cylinder in it's inverted position) to bottom (the lip) or vice
>>versa?
>>
>>just my two cents worth
>>
>>cheers
>>
>>Kim
>>
>>
>>--
>>D. Kim Lindaberry
>>Longview Community College
>>500 SW Longview Road
>>Art Department
>>Lee's Summit, MO 64108
>>USA
>>
>>to visit my web site go to:
>>http://www.kcmetro.cc.mo.us/longview/humanities/art/kiml/
>>to send e-mail to me use: mailto:kiml@kcmetro.cc.mo.us
>>
>
>--
>Steve Mills
>Bath
>UK
>home e-mail: stevemills@mudslinger.demon.co.uk
>work e-mail: stevemills@bathpotters.demon.co.uk
>own website: http://www.mudslinger.demon.co.uk
>BPS website: http://www.bathpotters.demon.co.uk
Andi Runt
Impressions in Pottery
State College, PA
jpri@email. psu.edu
Stephen Mills on thu 3 dec 98
In message , Andi Runt writes
>----------------------------Original message----------------------------
>Steve,
>What kind of "very absorbant insulating board" that isn't plaster? What's
>it called?
The material I use is a 25mm thick board used in fireproofing roofs and
ceilings. It uses Mica/Vermiculite as the chief ingredients, contains NO
asbestos, and in the UK goes under the Brand name "Vermiculux". my
workshop could not function without it!!
Steve
--
Steve Mills
Bath
UK
home e-mail: stevemills@mudslinger.demon.co.uk
work e-mail: stevemills@bathpotters.demon.co.uk
own website: http://www.mudslinger.demon.co.uk
BPS website: http://www.bathpotters.demon.co.uk
Christine Dubois on thu 3 dec 98
In my opinion clay dries from thinest part to thickest part. It just so
happens that "pots" are usually thinner at the rim than at the base.
Mildred Herot on sat 11 oct 03
I have devised my own system for reclaiming clay and, since I do not =
work consistently and do not produce large quantities of pottery, it =
works for me. I keep two lrge plastic cans handy. One for trimmings =
(and throw aways) and one with clay and water and I have a large paint =
mixed (courtesy of Home Depot) in the can to mix the clay and water. =
When I have the right consistency, I use a large scoop and put some of =
the slurry on a plaster bat and let it dry to the right consistency. =
Not a good way for full time potters but for part timers (like me) I =
find it successful.....Mildred Herot - Cheltenham, Pa.
sandy dvarishkis on tue 19 aug 08
For drying clay, I use a canvas army cot. I picked up my army cot for =
under $10.00 at our local Army Navy surplus store. Air circulation all =
around, cot can be moved to whereever, and when finished using, just =
fold up and store for later use.
sandy Dvarishkis
in Montana where it is another far too hot day, predicting 100 degrees
terrasand@hotmail.com
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