keramik on tue 30 oct 01
Tommy Humphries wrote
>Message: 1
Date: Mon, 29 Oct 2001 20:28:25 -0600
From: Tommy Humphries
Subject: wedging, puzzles, and throwing straight from the pug
I was making some 2 and 3 gallon pickle jars Sunday at work. 14 and 18
pounds respectively...balls of clay cut directly from the pugs, no =
wedging
or work of any kind. Same way as always... never have any S cracks, or =
ring
cracks... only the very occasional crack straight across, and that from =
not
getting them turned over in time.
I believe the secret is a well compressed bottom, very well sponged =
out(no
standing slip), and turning the pot over at the earliest possible =
moment.
Had a fellow watching me for an hour or so, 3rd year pottery student at =
some
University somewheres...don't remember the name right now. Took a lot =
of
pictures, couldn't believe that you could throw clay that hadn't been
wedged, and then coned 3 or 4 times once it was on the wheel. Told him "
hell if you do all that to the clay, it will be overworked before you
start!" I don't think he was convinced even after watching it =
done...over,
and over again.
I think that the way you treat the pot after it is made is the secret in
avoiding cracks, not in the way you treat the clay before. After all,
everything you do to that clay will be undone when you start throwing =
water
and centering, and opening the ball. The only part of the clay that will
remain unchanged is that minute amount at the bottom that is stuck to =
the
wheel head as the ball is thrown down.
Tommy Humphries
I have always been doing that, especially with big dinner plates and =
larger flat bowls.=20
When I mention it to people they throw their hands up in horror, so I =
stopped saying anything.=20
It works for me, it was shown to me by my tutor,=20
who comes from an industrial ceramics background and who is a production =
potter,=20
neither he nor I have every any problems with this method.
I reckon whatever works.....
Angela
UK, Essex
Bruce Girrell on tue 30 oct 01
I always throw the pugged clay without wedging, but I do two things prior to
beginning to form the piece.
1) I read (on Clayart) about turning the pug sideways to avoid S cracks and
I do that. I take the pugged clay and mash it down until its height is about
the same as its width, then turn it and form it into a squat cylinder in
such a way that the axis of the pugmill screw will be lying horizontally on
the wheelhead.
2) I cone the clay, usually about three times, before the final centering.
I can't remember the last time that I had an S crack. I don't know if either
or both of the above practices have anything to do with that or not, but
without the time to do a real study on it, I'll take mel's approach - do
what works and don't worry about why.
Bruce "despite all outward appearances, I actually can take a practical
approach" Girrell
in northern Michigan, where the wind and rain have stripped the leaves from
the trees. Maples, beeches, birches are all bare. Only the oaks hold on. The
white oaks put on quite a show this year - yellows, golds, maybe even some
oranges. They'll never match the maples for color, but definitely stood
apart from their more drab cousins, the red oaks.
Jeff Tsai on wed 31 oct 01
Yeah, I don't usually wedge my clay either. I just throw straight out
of the bag or pug mill. I used to have s-crack problems witht he
clay, But I just started being more careful to compress the bottom
well and the problem never really happened again.
-jeff
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