Leesh on mon 31 oct 05
I watched Tony Clennell's "Taking the Macho out of Big Ware" video this
weekend. (Nice video, Tony ... I enjoyed the "Ooops" also)
He makes a large knob for a large cassarole lid with an enclosed air pocket=
.
Similarly Diana Pancioli describes using extruded tubes for handles in her
book "Extruded Ceramics".
Are there any tricks, tips or concerns when using pieces with enclosed air
pockets in forms? I'm nervous about doing it for fear of having them explod=
e
in firing.
Leesh
clennell on mon 31 oct 05
Sour Cherry Pottery
> I watched Tony Clennell's "Taking the Macho out of Big Ware" video this
> weekend. (Nice video, Tony ... I enjoyed the "Ooops" also)
>
> He makes a large knob for a large cassarole lid with an enclosed air pocket.
> Similarly Diana Pancioli describes using extruded tubes for handles in her
> book "Extruded Ceramics".
>
> Are there any tricks, tips or concerns when using pieces with enclosed air
> pockets in forms? I'm nervous about doing it for fear of having them explode
> in firing.
>
> Leesh
>
Poke a hole in it. I use a flat pointed thing since i found a pin tool often
didn't actually make a hole. the hole filled back in when withdrawing the
pin tool.
Cheers,
Tony
Leesh on tue 1 nov 05
Hi Tony,
I noticed that you poked a hole in the wet clay, but was worrying that it
would close back up. Does the hole need to be large enough to remain open
through the bisque and glaze firings? Is it a problem if glaze fills it up?
Thanks,
Leesh
On 10/31/05, clennell wrote:
>
> Sour Cherry Pottery
>
> > I watched Tony Clennell's "Taking the Macho out of Big Ware" video this
> > weekend. (Nice video, Tony ... I enjoyed the "Ooops" also)
> >
> > He makes a large knob for a large cassarole lid with an enclosed air
> pocket.
> > Similarly Diana Pancioli describes using extruded tubes for handles in
> her
> > book "Extruded Ceramics".
> >
> > Are there any tricks, tips or concerns when using pieces with enclosed
> air
> > pockets in forms? I'm nervous about doing it for fear of having them
> explode
> > in firing.
> >
> > Leesh
> >
> Poke a hole in it. I use a flat pointed thing since i found a pin tool
> often
> didn't actually make a hole. the hole filled back in when withdrawing the
> pin tool.
> Cheers,
> Tony
>
>
> _________________________________________________________________________=
_____
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
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>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots@pclink.com.
>
clennell on tue 1 nov 05
Sour Cherry Pottery
> Hi Tony,
> I noticed that you poked a hole in the wet clay, but was worrying that it
> would close back up. Does the hole need to be large enough to remain open
> through the bisque and glaze firings? Is it a problem if glaze fills it up?
> Thanks,
> Leesh
Leesh: The hole is open during the bisque but I put some glaze in it to
cover it up in the glaze firing.
Cheers,
Tc
Vince Pitelka on tue 1 nov 05
> Poke a hole in it. I use a flat pointed thing since i found a pin tool
> often
> didn't actually make a hole. the hole filled back in when withdrawing the
> pin tool.
Tony -
I think that the question is how to fire small closed spaced without making
a vent hole, or with no vent hole remaining after the glaze firing. I'd
love to hear some answers too. I always teach students to avoid any trapped
air spaces, but I know that there are people who make hollow knobs or
handles with no visible vent hole after the glaze firing. I am assuming
that they just bisque fire so slowly that the pressure is able to escape
through the clay. Another approach I have heard of is to use a very tiny
rigid wire, like a piece of music wire to make a vent hole that subsequently
can be glazed over. I can't imagine there being any problem in the glaze
firing, since the clay is porous until it vitrifies. I think the real
challenge is to get the pice through the bisque, and thus a tiny vent hole
that subsequently gets glazed over might be the answer.
My own personal opinion is that it is not appropriate to leave any kind of
tiny vent hole in a closed air space in a functional piece of pottery, and
there is a very good reason. As the piece gets used and washed multiple
times, and as the air inside the closed space expands and contracts, small
amounts of dishwater are pulled in through the vent hole, creating a moist
atmosphere ideal for bacteria growth. Eventually you've got a good alien
colony growing in there. On the night that you are entertaining the CEO and
her husband you preheat the tureen and fill it with hot soup and set it out
on your best lace tablecloth with all the guests sitting around commenting
on the beautiful tureen and the delicious aroma of the soup and then the
side handles with hollow spaces begin to heat up and the vent holes start
oozing toxic slime that drips onto the tablecloth and the guests are so
disgusted that they all get up and leave and you subsequently loose all
credibility at the company and are eventually dismissed and turn to a life
of crime and substance abuse and ultimately end up homeless on the streets
of Hoboken New Jersey all because of having left vent holes in closed spaces
on a functional vessel. Hey, it could happen.
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
Leesh on tue 1 nov 05
Thanks Tony,
I really appreciate the wonderful tutorial in your video and look forward t=
o
putting it into practice.
As a beginner, I am always amazed at the fortune of having such
knowledgeable people here on this list to learn from. You may not want to
assume the title of "master," but I certainly consider you a skilled potter
and excellent teacher.
Leesh
On 11/1/05, clennell wrote:
>
> Sour Cherry Pottery
>
> > Hi Tony,
> > I noticed that you poked a hole in the wet clay, but was worrying that
> it
> > would close back up. Does the hole need to be large enough to remain
> open
> > through the bisque and glaze firings? Is it a problem if glaze fills it
> up?
> > Thanks,
> > Leesh
>
> Leesh: The hole is open during the bisque but I put some glaze in it to
> cover it up in the glaze firing.
> Cheers,
> Tc
>
>
> _________________________________________________________________________=
_____
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots@pclink.com.
>
earlk on tue 1 nov 05
On Tue, 2005-11-01 at 17:59 -0600, Vince Pitelka wrote:
> My own personal opinion is that it is not appropriate to leave any
> kind of
> tiny vent hole in a closed air space in a functional piece of pottery,
> and
> there is a very good reason.
Hey, I can testify to this one.
We have a set of soup bowls with hollow handles.
The handles are closed cylinders except for a 1/8"
hole on the bottom near the attachment to the bowl.
Run them through the dishwasher then take them
out of the cupboard a week later and they drip all over.
If I otherwise didn't like them so well I'd trash them
because of this.
earlk...
bothell, wa, usa
Louis Katz on wed 2 nov 05
A hollow handle on an old Wally Bivens cup picked up at a thrift store
in Helena Montana has a little pintool sized hole in it. I have removed
it from the microwave on a few occasions gushing hot fluids from the
pinhole. It was clear that this could become the "explosion in the
microwave pot" of liability nightmare.
Someone with some real knowledge could give you a formula for the
amount volume of space, the size of the hole and the effective wattage
of the microwave so that your knobs won't explode. I would consider
that if you make them bigger the space will fill easier, but empty
easier as well. If the hole is big enough it can't explode.
Louis
***Louisiana Mississippi Ceramics and Potters Information page*****
http://falcon.tamucc.edu/wiki/Katz/LAMIPotters
>>
>> Are there any tricks, tips or concerns when using pieces with
>> enclosed air
>> pockets in forms? I'm nervous about doing it for fear of having them
>> explode
>> in firing.
>>
>> Leesh
>>
> Poke a hole in it. I use a flat pointed thing
> _____________________________________
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