taube wilson on fri 11 feb 00
Hi,
Last night I worked with the student who had been having trouble
with spiral cracks around the bottom of her glazed pots.
The cracks definitely were there after bisque and opened up
during the glaze firings. I watched her wedge, and I think that's
where the problem is. She wedged a big spiral into her clay, squared
it off a bit, then put it down on the wheel with the spiral
facing up.
She's drying her pottery under a tent of plastic for at least
a week so I don't think it's uneven drying, but I suggested that
she tuck the plastic in around the base.
I'll let you all know how her next batch of pots is. Thanks
so much to everyone who helped us solve this mystery!
Taube Wilson
tpottery@hotmail.com
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
John K Dellow on sun 13 feb 00
Ok here is my thoughts on what might be happening. While drying
under plastic for a long time , the water from the drying process
condenses on the plastic and will run down & collect at the
bottom. The clay at the bottom ,which has plastic tucked under it
,might reabsorb the water which can causing minute cracks. That's
why I use cloth to cover my pots.
taube wilson wrote:
>
> ----------------------------Original message----------------------------
> Hi,
> Last night I worked with the student who had been having trouble
> with spiral cracks around the bottom of her glazed pots.
>
> The cracks definitely were there after bisque and opened up
> during the glaze firings. I watched her wedge, and I think that's
> where the problem is. She wedged a big spiral into her clay, squared
> it off a bit, then put it down on the wheel with the spiral
> facing up.
>
> She's drying her pottery under a tent of plastic for at least
> a week so I don't think it's uneven drying, but I suggested that
> she tuck the plastic in around the base.
>
> I'll let you all know how her next batch of pots is. Thanks
> so much to everyone who helped us solve this mystery!
>
> Taube Wilson
> tpottery@hotmail.com
> ______________________________________________________
> Get Your Private, Free Email at http://www.hotmail.com
--
John Dellow "the flower pot man"
Home Page http://www.welcome.to/jkdellow
http://digitalfire.com/education/people/dellow/
Robin Teas on mon 14 feb 00
In my experience spiral cracks at the bottom of a piece are due to improper
compressing after opening or leaving a puddle in the bottom as one throws,
causing the clay to become un- compressed.
Robin in WV.
John K Dellow wrote:
> ----------------------------Original message----------------------------
> Ok here is my thoughts on what might be happening. While drying
> under plastic for a long time , the water from the drying process
> condenses on the plastic and will run down & collect at the
> bottom. The clay at the bottom ,which has plastic tucked under it
> ,might reabsorb the water which can causing minute cracks. That's
> why I use cloth to cover my pots.
>
> taube wilson wrote:
> >
> > ----------------------------Original message----------------------------
> > Hi,
> > Last night I worked with the student who had been having trouble
> > with spiral cracks around the bottom of her glazed pots.
> >
> > The cracks definitely were there after bisque and opened up
> > during the glaze firings. I watched her wedge, and I think that's
> > where the problem is. She wedged a big spiral into her clay, squared
> > it off a bit, then put it down on the wheel with the spiral
> > facing up.
> >
> > She's drying her pottery under a tent of plastic for at least
> > a week so I don't think it's uneven drying, but I suggested that
> > she tuck the plastic in around the base.
> >
> > I'll let you all know how her next batch of pots is. Thanks
> > so much to everyone who helped us solve this mystery!
> >
> > Taube Wilson
> > tpottery@hotmail.com
> > ______________________________________________________
> > Get Your Private, Free Email at http://www.hotmail.com
>
> --
>
> John Dellow "the flower pot man"
> Home Page http://www.welcome.to/jkdellow
> http://digitalfire.com/education/people/dellow/
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