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Help Keeping Clay Centered On Wheel


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I am pretty new to the wheel, but I can center the clay perfectly. Sometimes when I start to open the pot/drop the hole, I notice that the inside gets off center although the outside stays just fine. I can't quite pinpoint what I'm doing wrong, other than that I might be pulling my hands off too quickly. As I keep working, I tend to get wobbly walls that frustrate me. Any tips?

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welcome, there have been many questions re: centering and opening.  if you try looking from the first page for posts about centering, you will find lots of good advice.  the biggest thing is to keep your hands on the clay through the entire process once you open the clay.  jerky movements result is jerky clay.  even if you are not doing more than following the clay upwards without squeezing or anything, keep your hands on it.

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Couple of things can help correct this:

 

  • Use the same position for your left hand as when centering, and then use the right hand braced against the left at the wrists to give support. If using the thumb, or fingers, use the top thumb section of the left to support the thumb/finger while opening.
  • Use a moderate, but not fast wheel speed
  • Stiffen the finger/fingers, and don't let them snap away from each other while opening
  • Always move hands away from the clay slowly so as to let the clay readjust to center after pressure, which pushes is off slightly.

 

 

best,

Pres

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Pres:

 

I watched all 3 videos on your blog.. some questions?

 

In the second video when you being making pulls--- from 1:00 to 3:30 primarily.  This is where I get concerned when I throw. I can see the clay spinning slightly out of round as I pull up, and I feel the need to correct. This is the area where I seem to falter the most: my natural inclination is to stop and bring it back to center. Thoughts?

 

Nerd

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In the first video, which is more about the opening up, you will notice that the clay is pretty well centered, but not perfect. I used to obsess over having the clay perfectly centered before throwing. Actually this piece of clay was a trimming chuck for another large bowl, that I had centered, dried a bit with a towel, and then turned a bowl upside down on to trim it. . . . .no, . . . I don't always use a Griffin Grip. :D So I brought it back to center after trimming the first bowl, and then started the opening up. You will notice though that I was negligent in my wedging, as I had one large air pocket that was causing problems in the form. I repaired the area twice, finally resolving the problem.

 

Now on the second video at the 1-3 area, which is where I think you are asking your question, a few things to point out.

  • I did one pull in there where I really did not push to thin the walls, but used the pull to recenter the form.
  • I took a minute or two to trim the top and recenter, re-compress the top rim before expanding the form more.
  • I am not good working these large bowls without a rib. . . my favorite you see me using is the bamboo spoon that I cut the handle off of and drilled a hole in the center for a gripping area. I can work this back and forth quite well to shape the inside of the bowl, and keep things even by bracing both hands together while working. No I do not support the outside to the bowl when doing this.
  • When working with any bowl shape. . . best to throw the form similar to a cylinder, but having it going slightly outward, not coned in like in a cylinder. Always keep a very thick rim, as this is the area that has to expand the most as the bowl gets expanded outward during shaping. 
  • Don't try to throw the bowl thin in the pulling except to get clay out of the base. The walls when the form is expanded have to have expansion clay for the form. Otherwise it will want to collapse.
  • This bowl was expanded even more once I set it aside for an hour and then went back to it once the clay had set up slightly. I going to trim it and raffle it off as a door prize for the class along with the other one.

 

Hope this helps answer your question, I am always willing and happy to try and explain why and how I do something.

 

 

best,

Pres

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Pres:

 

Ty for the explanations. One thing about watching your throwing videos, I have the luxury of asking questions about specific parts: most helpful.

Don't try to throw the bowl thin in the pulling except to get clay out of the base. The walls when the form is expanded have to have expansion clay for the form. Otherwise it will want to collapse.

 

This is where I am making my mistakes. I think I am trying to pull too much clay up in one pull???

How many pulls total did it take you to reach your finished height?

How much clay do you leave at the top-to further expand?

What was the wall thickness of the final thrown piece?

 

Matthew V pointed out to me that I was not opening my form wide enough before I began to pull up. Now you are addressing my other weakness- not controlling my pulls.  Very much appreciate you taking your time to help me fine tune my throwing skills.

 

Nerd

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Pres:

 

Ty for the explanations. One thing about watching your throwing videos, I have the luxury of asking questions about specific parts: most helpful.

This is where I am making my mistakes. I think I am trying to pull too much clay up in one pull???

 

When pulling anything, start with a stronger than you think pressure, and  get a healthy roll to start moving, then ease up on the pressure to move this thickness into the walls, not for added height in the beginning, then as you pull this "extra" clay is there to extend and thin the walls.

How many pulls total did it take you to reach your finished height?

They usually take about 4 pulls +/- one.

How much clay do you leave at the top-to further expand?

Rim of the raw form is between a 1/2 to 3/4.

What was the wall thickness of the final thrown piece?

Wall thickness is 1/4 to 3/8

 

Matthew V pointed out to me that I was not opening my form wide enough before I began to pull up. Now you are addressing my other weakness- not controlling my pulls.  Very much appreciate you taking your time to help me fine tune my throwing skills.

 

Nerd

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In the beginning of your third video I had noticed that you scored the inside of the pot. Later in the same video at about 1:30 I noticed what looks like you are poking the inside wall with a needle tool.

 

On the first I'm guessing you are repairing a defect?

 

In the second are you checking the wall thickness?

 

If not, whatcha  doing?

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As this piece of clay had been a throwing chuck for a previous large bowl, I had not wedged it as well as I should have. The scoring was the first attempt at resolving the air pocket(quite large). The second pin hole, was the final step in removing it almost completely. I usually wedge the clay at least 300 turns before throwing, in this case it was maybe 100 turns. At the same time though, teachable moments. It is possible to throw the pot with air bubbles, and it is possible to remove the air bubbles. At the same time we should also realize that air bubbles do not cause a pot to blow up. This bowl will be trimmed this weekend, and given as one of the door prizes for the class.

 

 

Hope I answered your question,

 

 

best,

Pres

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Yes you did, more than you may realize.

 

Two days ago my wife had thrown a pot that she was quite please with. While she was ribbing she found an air pocket also from not wedging properly. Disappointed, she decided she would wire the pot in half to see how she was doing, When she looked at the side walls she said she wished it could have been fixed.

 

Now I can tell her its possible to fix.

 

She trimmed the top and I'm betting she could have used that clay for the repair.

 

Thanks

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If she is still in beginner to intermediate mode there, she probably learned quite a bit about the pot from cutting it in half. I used to cut so many demonstrations pieces in half for students to see the way things should be, and yet I also looked at everyone of thee with my very critical eye. I learned quite a bit about the rhythm of my pulls, the amount of clay I left in the bottom, and the bottom sides, and rim thicknesses. These lessons have helped me to fine tune my own throwing. 

 

 

Glad I was able answer your questions in a way that may help her.

 

best,

Pres

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