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warpage of a teapot spout

updated thu 3 feb 11

 

Elisabeth Maurland on tue 1 feb 11


I have made many teapots with a long, drawn-out shape - very long spout, =
=3D
and very long handle. I cut the tip of the spout on a diagonal to =3D
further elongate the look.=3D20

=3D
http://www.elisabethmaurland.com/www.elisabethmaurland.com_index.html/Gall=
=3D
ery.html (bottom two pictures).

The clay shrinks, of course, and that makes the spout twist a little in =3D
the kiln, so that the diagonal cut isn't in the same place as it was =3D
when I put it in - it's twisted over to the - right? Left? That's the =3D
problem. I can't remember!=3D20
Last night, I was cutting the spouts, and to make up for the twisting, I =
=3D
always cut it crooked, so that it twists to where it's supposed to be. =3D
But suddenly I couldn't remember whether to cut it on the right side or =3D
the left.=3D20
I looked at some of the images for my first such teapots, but since they =
=3D
are on slides I can't tell which way is right.
I tried to think it out, but I'm not sure if I'm thinking about it =3D
logically. I throw in the standard direction.

Does anyone understand what I mean? What I ended up doing is cut the =3D
diagonal on the left a little (looking at the spout head on), thinking =3D
it will twist to the right and be on top where it's supposed to be. But =3D
I will be putting a lot of work into decorating the teapots, and I'd =3D
hate to waste days of work on something that will be useless.=3D20

Can someone help me think this out logically?

Thanks!

Elisabeth=3D

Hank Murrow on tue 1 feb 11


On Feb 1, 2011, at 9:12 AM, Elisabeth Maurland wrote:

> I'd hate to waste days of work on something that will be useless.=3D20
>=3D20
> Can someone help me think this out logically?

Dear Elisabeth;

The longer the spout the more it will twist.

If you look at the front of the pot, I find that cutting it with a slope =
=3D
down and to the left of around 15 to 12 degrees will bring it around =3D
straight after the fire. That is at Cone 10. Cone 5 may not require so =3D
steep a cut, as those clays are not as 'wet' in the fire.

Cheers, Hank=3D

Elisabeth Maurland on tue 1 feb 11


Hi Jeff,=3D20

That was how I was thinking, but I wasn't sure it was correct. I went =3D
with it anyway, so I'm happy to hear that I did it right. On to =3D
decorating!

Elisabeth
On Feb 1, 2011, at 12:33 PM, plasterjfl@aol.com wrote:

> Hey Elisabeth,
> =3D20
> The spout will "untwist" counter to the direction in which it was =3D
pulled. When I throw the wheel spins clockwise. I've "pulled" the spout =3D
in the opposite direction. As it fires it will unwind in the clockwise =3D
direction.
> =3D20
> By "standard" I presume you mean to say you throw in the counter =3D
clockwise direction? Your spouts will then unwind in the counter =3D
clockwise direction as well.
> =3D20
> If that makes sense?
> =3D20
> Good Luck
> =3D20
> Jeff Longtin
> Minneapolis
> =3D20
> In a message dated 2/1/2011 12:22:29 P.M. Central Standard Time, =3D
elisabeth@ELISABETHMAURLAND.COM writes:
> I have made many teapots with a long, drawn-out shape - very long =3D
spout, and very long handle. I cut the tip of the spout on a diagonal to =
=3D
further elongate the look.=3D20
>=3D20
> =3D
http://www.elisabethmaurland.com/www.elisabethmaurland.com_index.html/Gall=
=3D
ery.html (bottom two pictures).
>=3D20
> The clay shrinks, of course, and that makes the spout twist a little =3D
in the kiln, so that the diagonal cut isn't in the same place as it =3D
was when I put it in - it's twisted over to the - right? Left? That's =3D
the problem. I can't remember!=3D20
> Last night, I was cutting the spouts, and to make up for the twisting, =
=3D
I always cut it crooked, so that it twists to where it's supposed to be. =
=3D
But suddenly I couldn't remember whether to cut it on the right side or =3D
the left.=3D20
> I looked at some of the images for my first such teapots, but since =3D
they are on slides I can't tell which way is right.
> I tried to think it out, but I'm not sure if I'm thinking about it =3D
logically. I throw in the standard direction.
>=3D20
> Does anyone understand what I mean? What I ended up doing is cut the =3D
diagonal on the left a little (looking at the spout head on), thinking =3D
it will twist to the right and be on top where it's supposed to be. But =3D
I will be putting a lot of work into decorating the teapots, and I'd =3D
hate to waste days of work on something that will be useless.=3D20
>=3D20
> Can someone help me think this out logically?
>=3D20
> Thanks!
>=3D20
> Elisabeth=3D3D

Elisabeth Maurland on tue 1 feb 11


Hi Vicki,

This was a great way to express what I mean, and I should write it down. =
=3D
Then I did it right! Phew! I have done this so many times before, but =3D
suddenly I forgot.=3D20

Thank you.

Elisabeth
On Feb 1, 2011, at 12:30 PM, Victoria E. Hamilton wrote:

> Hi Elizabeth -
>=3D20
> I always cut my spouts on a diagonal, starting from the bottom at =3D
about 5
> o'clock and ending up at the top at about 11 o'clock. This should put =
=3D
the
> bottom "point" of the spout at about 6 o'clock when the spout unwinds =3D
to the
> right during your firing.
>=3D20
> Hope this helps.
>=3D20
> Vicki Hamilton
> Seattle=3D20
>=3D20
> -----Original Message-----
> From: Clayart [mailto:Clayart@LSV.CERAMICS.ORG] On Behalf Of Elisabeth
> Maurland
> Sent: Tuesday, February 01, 2011 9:13 AM
> To: Clayart@LSV.CERAMICS.ORG
> Subject: Warpage of a teapot spout
>=3D20
> I have made many teapots with a long, drawn-out shape - very long =3D
spout, and
> very long handle. I cut the tip of the spout on a diagonal to further
> elongate the look.=3D20
>=3D20
> =3D
http://www.elisabethmaurland.com/www.elisabethmaurland.com_index.html/Gall=
=3D
er
> y.html (bottom two pictures).
>=3D20
> The clay shrinks, of course, and that makes the spout twist a little =3D
in the
> kiln, so that the diagonal cut isn't in the same place as it was when =3D
I put
> it in - it's twisted over to the - right? Left? That's the problem. I =3D
can't
> remember!=3D20
> Last night, I was cutting the spouts, and to make up for the twisting, =
=3D
I
> always cut it crooked, so that it twists to where it's supposed to be. =
=3D
But
> suddenly I couldn't remember whether to cut it on the right side or =3D
the
> left.=3D20
> I looked at some of the images for my first such teapots, but since =3D
they are
> on slides I can't tell which way is right.
> I tried to think it out, but I'm not sure if I'm thinking about it
> logically. I throw in the standard direction.
>=3D20
> Does anyone understand what I mean? What I ended up doing is cut the
> diagonal on the left a little (looking at the spout head on), thinking =
=3D
it
> will twist to the right and be on top where it's supposed to be. But I =
=3D
will
> be putting a lot of work into decorating the teapots, and I'd hate to =3D
waste
> days of work on something that will be useless.=3D20
>=3D20
> Can someone help me think this out logically?
>=3D20
> Thanks!
>=3D20
> Elisabeth=3D3D
>=3D20

Jeff Brown on tue 1 feb 11


Hi Elizabeth,
teapot spouts twist in a clockwise direction when thrown righthanded with=
=3D
the=3D20
wheel going counter clockwise.

the cut on your spout should be higher on the right side as you look stra=
=3D
it into=3D20
the opening of the spout.

the photo link below shows the direction your spout will twist:
http://www.jeffbrownpottery.com/spout.jpg

Thank you,

Jeff Brown
1423 Pottery Highway 705
Seagrove, NC 27341
http://www.jeffbrownpottery.com



On Tue, 1 Feb 2011 11:12:39 -0600, Elisabeth Maurland=3D20
wrote:

>The clay shrinks, of course, and that makes the spout twist a little in =
=3D
the=3D20
kiln,=3D20

Snip...
I couldn't remember whether to cut it on the right side or the left.=3D20
I throw in the standard direction.
>
>Does anyone understand what I mean? >
>Can someone help me think this out logically?
>
>Thanks!
>
>Elisabeth

Jeff Brown on tue 1 feb 11


Actually, clay tightens as it shrinks...the clay particles go closer to e=
=3D
ach=3D20
other... so the spout tightens If a spout "unwinds' then clay would be=3D20=
=3D

expanding.

from my experience...=3D20

>On Feb 1, 2011, at 12:33 PM, plasterjfl@aol.com wrote:
>
>> Hey Elisabeth,
>>=3D20=3D20
>> The spout will "untwist" counter to the direction in which it was pull=
=3D
ed.=3D20
When I throw the wheel spins clockwise. I've "pulled" the spout in the=3D20=
=3D

opposite direction. As it fires it will unwind in the clockwise direction=
=3D
.
>>=3D20=3D20
>> By "standard" I presume you mean to say you throw in the counter=3D20
clockwise direction? Your spouts will then unwind in the counter clockwis=
=3D
e=3D20
direction as well.
>>=3D20=3D20
>> If that makes sense?
>>=3D20=3D20
>> Good Luck
>>=3D20=3D20
>> Jeff Longtin
>> Minneapolis
>>=3D20=3D20
>> In a message dated 2/1/2011 12:22:29 P.M. Central Standard Time,=3D20
elisabeth@ELISABETHMAURLAND.COM writes:
>> I have made many teapots with a long, drawn-out shape - very long=3D20
spout, and very long handle. I cut the tip of the spout on a diagonal to =
=3D
further=3D20
elongate the look.=3D20
>>=3D20
>>=3D20
http://www.elisabethmaurland.com/www.elisabethmaurland.com_index.html/Gal=
=3D

lery.html (bottom two pictures).
>>=3D20
>> The clay shrinks, of course, and that makes the spout twist a little i=
=3D
n the=3D20
kiln, so that the diagonal cut isn't in the same place as it was when =
=3D
I put it=3D20
in - it's twisted over to the - right? Left? That's the problem. I can't=3D=
20=3D

remember!=3D20
>> Last night, I was cutting the spouts, and to make up for the twisting,=
=3D
I=3D20
always cut it crooked, so that it twists to where it's supposed to be. Bu=
=3D
t=3D20
suddenly I couldn't remember whether to cut it on the right side or the l=
=3D
eft.=3D20
>> I looked at some of the images for my first such teapots, but since th=
=3D
ey=3D20
are on slides I can't tell which way is right.
>> I tried to think it out, but I'm not sure if I'm thinking about it log=
=3D
ically. I=3D20
throw in the standard direction.
>>=3D20
>> Does anyone understand what I mean? What I ended up doing is cut the=3D2=
0=3D

diagonal on the left a little (looking at the spout head on), thinking it=
=3D
will twist=3D20
to the right and be on top where it's supposed to be. But I will be putti=
=3D
ng a lot=3D20
of work into decorating the teapots, and I'd hate to waste days of work o=
=3D
n=3D20
something that will be useless.=3D20
>>=3D20
>> Can someone help me think this out logically?
>>=3D20
>> Thanks!
>>=3D20
>> Elisabeth=3D3D

Vince Pitelka on tue 1 feb 11


Jeff Brown wrote:
Teapot spouts twist in a clockwise direction when thrown righthanded with
the wheel going counter clockwise. The cut on your spout should be higher o=
n
the right side as you look straight into the opening of the spout. The phot=
o
link below shows the direction your spout will twist:
http://www.jeffbrownpottery.com/spout.jpg"

Jeff is correct, and I thought a little more explanation might be
appreciated. When you throw a pot, you are holding the clay back while the
wheel is trying to spin it, so if the wheel is turning counterclockwise, th=
e
grain structure of the clay in a thrown pot is a very steep clockwise spira=
l
up the pot. Because clay shrinks most across the grain structure, the clay
shrinks slightly more in a clockwise direction, because the greatest
contraction between platelets is in a steep clockwise spiral down the pot,
across the grain structure. Larger diameter pots do not even show this
shrinkage across the grain structure, but very small-diameter thrown forms
like candlesticks and teapot spouts can show it in very dramatic fashion.
When I was a studio potter I once tried to make "jack-be-nimble"
candlesticks, each with a handle extending from the edge of the candle cup
out to the outer edge of the attached "saucer." These were made in
porcelain, which of course has the highest firing shrinkage. They came out
of the kiln with every one of the handles ripped right off the edge of the
saucer, and the stems bent from the force of shrinkage. The next batch, I
just formed a handle that was attached entirely to the rim of the saucer,
like an actual "jack-be-nimble" candlestick, and that worked just fine.
- Vince

Vince Pitelka
Appalachian Center for Craft
Tennessee Tech University
vpitelka@dtccom.net; wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka

Jeff Longtin on wed 2 feb 11


Hey Elisabeth,

I haven't thrown in years. When I did throw teapots were my thing. (Teapots
have also become my thing since becoming a slip caster.)

I had few failures when I was a wheel thrower, and I thought I applied
logic to the "twist" issue, but comments by Vince and Jeff suggest my memor=
y
does not serve me well.

I responded offline only because I was basing my advice on memory and not
sure if I was correct.

I stand corrected.

Jeff Longtin
Minneapolis

ps. I don't recall having many twist issues to begin with. For most of my
wheel throwing years I threw on a kick wheel. I wonder if the slower speed
reduced the twist exerted on the spout?



In a message dated 2/1/2011 2:14:09 P.M. Central Standard Time,
elisabeth@ELISABETHMAURLAND.COM writes:

Hi Jeff,


That was how I was thinking, but I wasn't sure it was correct. I went with
it anyway, so I'm happy to hear that I did it right. On to decorating!


Elisabeth

On Feb 1, 2011, at 12:33 PM, _plasterjfl@aol.com_
(mailto:plasterjfl@aol.com) wrote:



Hey Elisabeth,

The spout will "untwist" counter to the direction in which it was pulled.
When I throw the wheel spins clockwise. I've "pulled" the spout in the
opposite direction. As it fires it will unwind in the clockwise direction.

By "standard" I presume you mean to say you throw in the counter clockwise
direction? Your spouts will then unwind in the counter clockwise direction
as well.

If that makes sense?

Good Luck

Jeff Longtin
Minneapolis


In a message dated 2/1/2011 12:22:29 P.M. Central Standard Time,
_elisabeth@ELISABETHMAURLAND.COM_ (mailto:elisabeth@ELISABETHMAURLAND.COM) =
writes:

I have made many teapots with a long, drawn-out shape - very long spout,
and very long handle. I cut the tip of the spout on a diagonal to further
elongate the look.

_http://www.elisabethmaurland.com/www.elisabethmaurland.com_index.html/Gall=
e
ry.html_
(http://www.elisabethmaurland.com/www.elisabethmaurland.com_index.html/Gall=
ery.html) (bottom two pictures).

The clay shrinks, of course, and that makes the spout twist a little in
the kiln, so that the diagonal cut isn't in the same place as it was when =
I
put it in - it's twisted over to the - right? Left? That's the problem. I
can't remember!
Last night, I was cutting the spouts, and to make up for the twisting, I
always cut it crooked, so that it twists to where it's supposed to be. But
suddenly I couldn't remember whether to cut it on the right side or the
left.
I looked at some of the images for my first such teapots, but since they
are on slides I can't tell which way is right.
I tried to think it out, but I'm not sure if I'm thinking about it
logically. I throw in the standard direction.

Does anyone understand what I mean? What I ended up doing is cut the
diagonal on the left a little (looking at the spout head on), thinking it =
will
twist to the right and be on top where it's supposed to be. But I will be
putting a lot of work into decorating the teapots, and I'd hate to waste d=
ays
of work on something that will be useless.

Can someone help me think this out logically?

Thanks!

Elisabeth=3D