vince pitelka on thu 14 jun 01
> No matter how you cut it, the spout is going to twist in the opposite
> direction from which it was thrown.
Lisa -
This can be confusing for some people. Most of us throw with the wheel
going counter-clockwise, which means that the throwing spiral, created by
drag on the clay, is going clockwise, and the spout will twist further in
the same direction as the throwing spiral. As I understand it this is
because the clay shrinks more across the grain than with the grain, and the
grain structure follows the throwing spiral. During vitrification the
greatest shrinkage in the walls of such a form is on a diagonal opposite
the diagonal of the throwing spiral. The end result is that the spout
twists even further in the same direction that it was already twisted by the
throwing spiral. The smaller the diameter of a thrown form as compared to
it's height, the greater the twist. I learned this the hard way in
production in California when I made a big load of tall slender porcelain
candlesticks that each had a handle connecting base and rim. In the
glaze-firing the shafts twisted and every one of those handles yanked loose.
So you are correct - if the spout is thrown with the wheel turning
counter-clockwise, then the spout will twist clockwise during vitrification
shrinkage. For an average spout the additional twist seems to be about 30
degrees, but for a shorter spout it will be less and a longer one it will be
more.
Did I just further confuse things? Did I obfuscate rather than illuminate?
I hope not. Sometimes more information is too much information, although it
is always hard to know when to stop. In class I always know when I am
providing too much explanation when my students all adopt that 1000-mile
stare, otherwise known as GES (glassy-eye syndrome), when they are gazing
right through me at some wonderful place deep within their imagination.
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
http://www.craftcenter.tntech.edu/
Cat Jarosz on thu 14 jun 01
Hi y'all... got a question about teapot spouts that common sense has not
been able to play a part for me .... I'm hoping that I wont have to lose
these teapots while I learn first hand and with your help maybe I wont have
to...
What I'm doing is taking a regular thrown off the hump spout , when it is
leather hard I cut it at an angle and re- attaching it at a 45 degree
angle... (this is done before its attached to t-pot. so here I have a
spout that normally would twist in high fire but now its been altered
severely ... is it still going to twist? which way ? ps have not put
any birdie lips or cut the end of the spout I left it round like I threw
it... I'm guessing that if it was gonna go in any direction it would be
counter clockwise as it was re attached that way... Has anyone had first
hand experience with this type of spout ? Clay memory is long and clay
has a way of making everyone humble... Thanks for taking time to read this
and answer.
Cat in the hot humid carolina mnts .... gonna get pictures taken of moi in
studio today for advertising purposes and for Clay times sept /oct issue
!!!! thanks to clay art , nceca and russel Fouts slide show in the clay
art room in charlotte !!!! This is a great resource is it not !!!
{{{{HUGS}}}}
dan mickey on thu 14 jun 01
cat,
i use to do spouts that way and never gave the idea much thought. I am
assuming that by cutting @ 45 deg. angle you mean the middle of the spout. I
always reattached them and just stuck them on the way i do any spout, at 11
oclock. i found out that they both just kinda balanced each other out in the
end, or maybe the bigger bottom part just had more torque? maybe someone who
makes these spouts can elaborate more than me, i am sure. by the way
congrats on the claytimes article, can't wait to see it. so nice to see
another guild member in print!
shane mickey
_______________________________________________________
Send a cool gift with your E-Card
http://www.bluemountain.com/giftcenter/
L. P. Skeen on thu 14 jun 01
Cat,
No matter how you cut it, the spout is going to twist in the opposite
direction from which it was thrown. Since you have cut the spout and
re-attached, each PIECE of the spout should twist. I did this kind of thing
once as an experiment making salt pigs, at ^10, but had no trouble w/ the
twist. OTOH, that could have been dumb luck. If you are using a wheel
that spins counterclockwise, the spout will twist clockwise. :)
Lisa in flatter NC. Wish I was up there where you are. Come to think of
it, I could be. Where are you exactly? Is it day-trippable? Surely there
are more potters than just you up there....Sarah HOuse is up there somewhere
too......
L
----- Original Message -----
From: Cat Jarosz
>so here I have a spout that normally would twist in high fire but now its
been altered
> severely ... is it still going to twist? which way ?
Cat Jarosz on mon 18 jun 01
Dear Shane thanks :o) sure appreciate the answer... Yours was
problebly the most understandable LOL... dang clay is a visual medium is
it not !!!! Hard to say with words what is sooooo easily done with your
hands ... the good thing is I found out I am not alone in not being able to
explain some things clearly with words... thanks for taking the time
to read and answer my request for imfo, it really helped me... CAT
| |
|
