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Teapot Spouts 'unwinding' When Fired?


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Another question...

 

I made my first teapots last year and noticed that the spouts have twisted slightly. The two pots in the photos (blue one was first rather immature attempt at stripes) were made with a basic grogged stoneware both reduction fired (>12) in the kiln where I did my evening class.

 

Looking from the front (attached images) they have twisted a few degrees clockwise Pretty sure they weren't like that when I stuck em on!

 

Could this be down to the clay unwinding from being wedged and /or thrown?

 

  • QUESTION:  If so, what on earth can I do to avoid it happening again?

 

In future my pots will be fired in my new electric kiln at cone 6 and prob made with ungrogged buff stoneware or white stoneware.

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I can't comment on the twisty spouts but I adore the blue teapot! Did you brush the glaze on?

Both pots were dipped, the blue one in shiny blue then a matt white over the top of it, leaving bands of darker blue showing, I also rubbed off some of the top layer of white glaze in places.

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I have had to deal with the unwinding quite a bit on teapots. You can do as others have said here, by putting it on crooked, or by cutting after it is on. Myself, often I don't cut the spout as the cut is usually an aesthetic thing. For me it does not effect the way the pot functions. If wanting to cut, your have to think of the spiral and the unwind So for a counter rotating wheel, in most case my cut is about 5 to 8 degrees toward 90 when looking at the pot with the spout pointing at me.

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The spouts aren't unwinding, they are actually winding further. Imagine holding onto the top of the spout as your wheel slowly spins (clockwise) and twisting it. It continues to twist in that direction when fired. As the Vince article says, it has to do with the orientation of the clay particles. Damn those pesky platelets!

 

If you don't cut the end of the spout at an angle, the twist won't show. But if you do cut it at an angle, a good place to start is to put the bottom edge of the cut at about 5 o'clock as you look into the spout. Different clays will twist differently, and your throwing technique will also affect the twist. I have some students whose spouts twist a lot, others who barley get any twist.

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Very interesting, because my pots when you look at them from the front, the spouts have both twisted clockwise which is the way they must spiral/twist on the wheel (assuming wheel goes anti-clock which mine does). It seems counter-intuitive.

 

But I can imagine that if the clay expands in firing, the spiral opens up further, as it later cools the platelets don't want to return and get a bit stuck???

 

The spouts aren't unwinding, they are actually winding further. Imagine holding onto the top of the spout as your wheel slowly spins (clockwise) and twisting it. It continues to twist in that direction when fired. As the Vince article says, it has to do with the orientation of the clay particles. Damn those pesky platelets!

 

If you don't cut the end of the spout at an angle, the twist won't show. But if you do cut it at an angle, a good place to start is to put the bottom edge of the cut at about 5 o'clock as you look into the spout. Different clays will twist differently, and your throwing technique will also affect the twist. I have some students whose spouts twist a lot, others who barley get any twist.

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Very interesting, because my pots when you look at them from the front, the spouts have both twisted clockwise which is the way they must spiral/twist on the wheel (assuming wheel goes anti-clock which mine does). It seems counter-intuitive.

 

But I can imagine that if the clay expands in firing, the spiral opens up further, as it later cools the platelets don't want to return and get a bit stuck???

 

The spouts aren't unwinding, they are actually winding further. Imagine holding onto the top of the spout as your wheel slowly spins (clockwise) and twisting it. It continues to twist in that direction when fired. As the Vince article says, it has to do with the orientation of the clay particles. Damn those pesky platelets!

 

If you don't cut the end of the spout at an angle, the twist won't show. But if you do cut it at an angle, a good place to start is to put the bottom edge of the cut at about 5 o'clock as you look into the spout. Different clays will twist differently, and your throwing technique will also affect the twist. I have some students whose spouts twist a lot, others who barley get any twist.

 

 

Yes, it is counter-intuitive. You would think they would untwist, but they continue to twist in the same direction as the torque/twist applied during throwing. It's not really about the torque/twist so much as it is about clay particle orientation due to the pressure of your fingers.

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as your wheel slowly spins (clockwise) and twisting it. It continues to twist in that direction when fired...

 

...a good place to start is to put the bottom edge of the cut at about 5 o'clock as you look into the spout...

Neil,

 

Very good points. But just to avoid further confusion... The usual counterclockwise rotation of the wheel would require placing the bottom (front) cut point at 5 o'clock.

 

It's like when you continue winding an existing steel spring, it will tend to become shorter (tighter). The clay "spring" (thrown cylinder), while drying/firing, becomes shorter, and it causes it to wind more.

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Guest JBaymore

See the .pdf reference that Norm posted above.

 

Every clay body, firing schedule, and person's particular throwing sdkills will affect the amount of the twist. So you have to "learn" your own situation.

 

We're back to that ole' "test, test, test" thing again.

 

best,

 

.............john

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as your wheel slowly spins (clockwise) and twisting it. It continues to twist in that direction when fired...

 

...a good place to start is to put the bottom edge of the cut at about 5 o'clock as you look into the spout...

Neil,

 

Very good points. But just to avoid further confusion... The usual counterclockwise rotation of the wheel would require placing the bottom (front) cut point at 5 o'clock.

 

It's like when you continue winding an existing steel spring, it will tend to become shorter (tighter). The clay "spring" (thrown cylinder), while drying/firing, becomes shorter, and it causes it to wind more.

 

 

 Yes, I was referring to the cut edge at the tip of the spout. The bottom edge should aim to 5 o'clock. Good drawing!

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Just to add to what everyone else has said ... aim the bottom edge of the spout lip at 5 o'clock if you are right-handed. Left-handers should aim for 7 o'clock.

 

It's not about handedness. It's about which direction the wheel was spinning when the spout was made. Left handed potters do not necessarily throw clockwise. None of my left handed students thrown clockwise. Western cultures tend to throw counter-clockwise, eastern cultures clockwise.

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I'm left handed,Marcia is left handed, Michael Cardew was left handed. We all throw with the wheel turning counter clockwise. I have made a heck of a lot of teapots I my time. I don't bother trimming the tip. They look fine. It has nothing to do with handedness, but the rotation of the wheel.

TJJ.

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Just to add to what everyone else has said ... aim the bottom edge of the spout lip at 5 o'clock if you are right-handed. Left-handers should aim for 7 o'clock.

 

It's not about handedness. It's about which direction the wheel was spinning when the spout was made. Left handed potters do not necessarily throw clockwise. None of my left handed students thrown clockwise. Western cultures tend to throw counter-clockwise, eastern cultures clockwise.

 

 

You're right, I should have said, anyone who throws with a clockwise wheel should aim for 7 o'clock.

 

In my local circle, the righties throw counter-clockwise and the lefties throw clockwise.

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Just to add to what everyone else has said ... aim the bottom edge of the spout lip at 5 o'clock if you are right-handed. Left-handers should aim for 7 o'clock.

 

It's not about handedness. It's about which direction the wheel was spinning when the spout was made. Left handed potters do not necessarily throw clockwise. None of my left handed students thrown clockwise. Western cultures tend to throw counter-clockwise, eastern cultures clockwise.

 

 

You're right, I should have said, anyone who throws with a clockwise wheel should aim for 7 o'clock.

 

In my local circle, the righties throw counter-clockwise and the lefties throw clockwise.

 

 

The reason I urge my lefties to throw counter-clockwise is because there are a lot of studios out there that still have old wheels that only run that direction. You never know when you might end up at a workshop and have to deal with it.

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I can't comment on the twisty spouts but I adore the blue teapot! Did you brush the glaze on?

Both pots were dipped, the blue one in shiny blue then a matt white over the top of it, leaving bands of darker blue showing, I also rubbed off some of the top layer of white glaze in places.

 

Even with the slightly wonky spout I think it's Fab! And thanks for telling how you glazed it. I can't really say that I've actually glazed anything...with the exception of a 3hr dip-a-thon to wrap up a miserable 6wks beginner pottery course at the local community college. I can't count that as experience and keep a straight face!

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