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warping mugs

updated thu 28 jan 99

 

Chris Schafale on mon 25 jan 99

Hi folks,

OK, now I've solved my cracking problem, and my glazes (knock wood)
seem to be sticking to my pots, I'm turning my attention to another
nagging issue. I like making mugs, and I've made quite a few. I
even enjoy pulling handles and I think I'm moderately good at it.
However, some not-insignificant proportion of my mugs end up not
quite round. I would swear that they're fine immediately after
I've put the handle on, while they're still leather hard, but
they seem to warp as they dry or perhaps sometimes in the
bisque. I suspect it has something to do with the handle attachment,
or maybe the stress created by the weight or tension of the handle as
it dries. My handles are usually oval in cross-section, making them
quite a bit thicker than the wall of the pot they are attached to,
and I usually have an even heavier area right near the upper
attachment, where the handle blends into the rest of the pot (for the
"growing out of the pot" look).

Any suggestions? Thanks in advance.

Chris
Light One Candle Pottery
Fuquay-Varina, NC
candle@nuteknet.com

John K. Dellow on tue 26 jan 99




> David leach pushes his cups out of round to compensate for the weight of
> the handle. The idea is for the cup to be pulled back into round by the
> handle during the glaze firing.

--

John Dellow "the flower pot man"
ICQ : #2193986 {jacka}
E-mail : dellow@usa.net
25 Hugh Guinea Ct, Worongary Q 4213
Ph:+61-7-55302875 Fax:+61-7-55253585
Home Page : http://welcome.to/jkdellow

Lili Krakowski on wed 27 jan 99

Oy. Ok. Taking it from the top. Some clay bodies seem to warp more
than others. As I assume you are buying the body, try a couple of others.
Your may be throwing too thin. If you wear a backpack you will understand
what I am saying next. The handle is like a backpack. A great big pack
on a little bitty skinny person is going to make it hard for that person
to walk. Right? A backpack has to be in proportion to the person
carrying it--or why several camping supply houses tell you what size
person the specific pack is for. You may be distorting the mugs yourself
as you put the handles on. Support the inside of the mug well as you
squoosh the handle on. You may be drying the mugs too fast and in a
drafty condition. Remember: the mug is thinner, dries faster than the
handle. You may be waiting a bit too long before you put the handles on;
see previous explanation. Try drying your mugs slowly under plastic on
isde a styrofoam cooler. Whatever you do, not near a heater, kiln, fan,
door, window where there is draft or unequal heat. Buy a rubber ball.
Stick it GENTLY into the top of the mugs and give a little turn. This
will put it back in the round. But it must be done while the mug is still
pretty damp or it will crack.

Last: GENTLY GENTLY. I am amazed with students how they slam and bang
thir pots about. Treat each little pot like a newborn baby. Handle it as
gnetly as you can.

Good luck

Lili Krakowski