clennell on mon 19 jul 99
I've said it before and I'll say it again "I've never seen a crack I didn't
like." I just refired two pots in our gas kiln from the throat arch of our
wood kiln. These two pots got wood thrown on them and they were buried in
coals during the firing and for days after. The colour on them is to die
for. Yes, they cracked where the wood hit them , they are my best pots
from the firing. Are they for sale. Yes- reluctantly. Yes because I need
the money, yes because I love the surface and yes I am a crack addict.
cheers,
Tony
Tony and Sheila Clennell
Sour Cherry Pottery
4545 King St.
Beamsville, On. L0R 1B1
Allyson May on sat 23 aug 03
I am new to ClayArt (about 2 weeks) and have really enjoyed the =
discussions thus far. I do email every morning after breakfast and the =
ClayArt mails really get my mind going before hitting the studio. I =
have a question which I hope isn't too amateurish for the group =
resulting in a reprimand and a list of required reading. I have been =
commissioned to make a few medium sized water pitchers. Water pitchers =
not really being in my repertoire, I set out to do my best. The =
pitchers were thrown from cone 6 porcelain and trimmed. The handles =
were pulled from the same clay and attached with scoring, slipping, and =
even a little vinegar to help strengthen the bond. Everything was =
wrapped in plastic and allowed to dry slowly (Mainly because nothing =
dries fast in my basement studio!). As each piece dried a crack =
developed at the top attachment sight of each handle. I repaired cracks =
with APT II Ceramic Enhancer and bisque fired. Most seem OK although 2 =
still show a hairline crack which I hope will be filled with glaze. How =
do I keep these cracks from developing in the beginning? I do a lot of =
hand building in my decorative work (boxes, large vessels, mostly Raku) =
and I don't have problems with cracks so the handle thing is perplexing. =
Any ideas would be appreciated.
As a little side note, the WD-40 and duct tape thing was outstanding. I =
can visualize it cross stitched on a lovely decorative pillow!
Allyson May
Stoney Creek Pottery
Full Time Mommy,
Part Time Potter
Carol Gardner on sat 23 aug 03
Dear Allyson: I have had that problem, too, depending on the clay. It =
may me the difference in the dryness at the top of the jug and the wet =
slip & handle. A friend suggested putting liquid wax on the joints. It =
has worked for me.=20
Carol Gardner
Sunny Denver
----- Original Message -----=20
From: Allyson May=20
To: CLAYART@LSV.CERAMICS.ORG=20
Sent: Saturday, August 23, 2003 8:58 AM
Subject: Cracks!
. How do I keep these cracks from developing in the beginning? =20
Allyson May
Stoney Creek Pottery
Full Time Mommy,
Part Time Potter
=
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william schran on sun 24 aug 03
Allyson wrote: > As each piece dried a crack developed at the top
attachment sight of each handle. I repaired cracks with APT II
Ceramic Enhancer and bisque fired. Most seem OK although 2 still
show a hairline crack which I hope will be filled with glaze.<
I've found working with porcelain on forms with handles often quite a
pain in the butt. Whether cups, teapots or pitchers, I've always had
some develop cracks at the joints at one time or another. Certainly
the different states of moisture content must be the culprit.
Porcelain seems especially sensitive to joining areas of even
slightly different dryness. I usually score the area of attachment on
the body, dab on a little water, then add slurry and attach the
handle. I cover and allow slow drying and this seems to work 80-90%
of the time. When a crack does appear, I have some porcelain paper
clay (made from same clay body) stored as a dry sheet, that I wet to
slurry state and jam into the crack when the pot is dry. This has
always repaired the problem.
I would not rely on the glaze filling the crack and creating a secure
attachment.
Bill
Lee Love on sun 24 aug 03
Sometimes, with small cracks in greenware or bisque, you can burnish them
with a stick and they will seal. A chopstick that you round with
sandpaper or by rubbing on concrete is a good tool. I use a piece of
bamboo for this.
Lee In Mashiko, Japan
Karen Ford on mon 25 aug 03
> Allyson wrote: > As each piece dried a crack developed at the top
> attachment sight of each handle. I repaired cracks with APT II
> Ceramic Enhancer and bisque fired. Most seem OK although 2 still
> show a hairline crack which I hope will be filled with glaze.<
>
> I've found working with porcelain on forms with handles often quite a
> pain in the butt. Whether cups, teapots or pitchers, I've always had
> some develop cracks at the joints at one time or another. Certainly
> the different states of moisture content must be the culprit.
> Porcelain seems especially sensitive to joining areas of even
> slightly different dryness. I usually score the area of attachment on
> the body, dab on a little water, then add slurry and attach the
> handle. I cover and allow slow drying and this seems to work 80-90%
> of the time. When a crack does appear, I have some porcelain paper
> clay (made from same clay body) stored as a dry sheet, that I wet to
> slurry state and jam into the crack when the pot is dry. This has
> always repaired the problem.
> I would not rely on the glaze filling the crack and creating a secure
> attachment.
> Bill
>
> ______________________________________________________________________________
> 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.
I work In Porcelain as well; have you tried using wax to cover the joints
where the cracks usually appear? It really helps dry even slower than just
covering the mugs. Also using "Magic Water" instead of Apt II for joining
just about anything at any state of dryness helps.
Magic Water
1 gallon water
3 tbs Sodium Silicate
3 tsp Soda Ash
Just mix and store in smaller batches. It doesn't evaporate easily.
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