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Looking For Alternative Ways To Hold Down Pots For Trimming

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Those blobs of clay seem to get in the way no matter how small.

A griffin grip with its knobs doesn't seem any better.

I have a vacuum chuck for my wood lathe but I'm sure I'd collapse the clay bottoms if I'd try it.

 

There's gotta be a better way that everybody knows but me.

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How are the blobs of clay getting in the way? You should only need to trim the bottom inch or so.

 

You can trim without any anchors. You just have to push hard enough on the bottom. Put a Snapple lid on there to distribute the pressure over a greater area and you can push really hard.

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It must be the woodturner in me, I seem to like to trim the outside from top to bottom to get a better curve. I need to look at differently

 

I tried using a lid with no anchors, I must have not held it down hard enough. I'll try that again.

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Bill van Gilder has a Youtube video where he puts clay on the wheelhead, presses it flat, then uses his finger at different distances from the center to make concentric rings.  This pad is about a half inch thick.  The surfaces of the raised ridges need to be scraped with a metal rib so they're not sticky. The pot to be trimmed is centered and held down with a hand on the bottom, or a poker chip or snapple cap or round piece cut from an old credit card.

 

There are also foam bats made for trimming.  Look for one on a supplier's website.

 

Cynthia

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Thanks Marcia - I tried that and the pot ran away from me, I'll try again I think I'm being too gentle. I also tried a non-slip shelve liner (my wife didn't find out yet) to no avail. Is it possible my wheel head is slippery because its new? Maybe I can scuff it up.

 

Thanks Cynthia I'll give those a try.

 

I was thinking of making a concave MDO bat, has anyone tried that?

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Unless I have missed the best time to trim (wait too long) I typically can get away with just dampening the bat head and pressing slightly down on it and it will almost vacuum seal it to the head. If you trim while still slightly damp you do not have to put as much pressure on your tool so it is not as likely to move.

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Thanks Marcia - I tried that and the pot ran away from me, I'll try again I think I'm being too gentle. I also tried a non-slip shelve liner (my wife didn't find out yet) to no avail. Is it possible my wheel head is slippery because its new? Maybe I can scuff it up.

You just dampen the lip , hold it for one or 2 complete spins, it should be stuck. Read Misfit. It is the same procedure.

Marcia

 

Thanks Cynthia I'll give those a try.

 

I was thinking of making a concave MDO bat, has anyone tried that?

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The picture doesn't look like much but the neoprene disc works extremely well to hold pots down. Damp sponge on the wheelhead, put the neoprene disc on it then damp sponge on the top surface. It holds most forms except for tall skinny ones with no wads of clay. It also works to hold onto and grab wood batts with foam on top. Sometimes I have to burp the neoprene to get the pots off. The only drawback is you can't tap center as the pots won't slide easily. (I run my finger on the damp top to make a circle roughly the diameter of the pot rim that I will be sticking down to get it pretty close then adjust it if necessary) This one is about 20 years old, no adhesive on the back. For the past few years I've seen them at Seattle Pottery Supply with an adhesive backing to stick them onto batts. These came out long before Giffen Grips and are getting harder to find. 

http://www.seattlepotterysupply.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=sps_ecat&Product_Code=42084&Category_Code=

post-747-0-46035600-1480549464_thumb.jpg

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Interesting bciskepottery thanks

 

Min I have a roll of neoprene somewhere, something to try, thanks

 

Mistfit, I think you may be on to something, I may have waited too long before trimming and need to slow down the drying a bit.

 

Marcia were you planning on posting something that got lost?

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ronsa, if you have dried it beyond perfect for trimming, put the pot inside a plastic grocery bag with a sort of wet sponge.  not touching the pot, but in some container that will keep the liquid from touching the pot.  you just want to humidify the thing.  it might be fine the next day.

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I've used a lot of methods, from the little bearinged disk that sits on the top of the pot in the center, to the damp wheel head, to the clay chocks when I first learned how to trim. By far, for me, is a Griffin Grip. Most items are quick on it, and easy to use. Sometimes I even reverse trim putting the sliders on the inside of the pot so that I can trim all the way down to the rim. This acts much the same way as a chuck does where the pot sits upside down over the chuck. All in all, you just have to find a method that works for you. If you are trimming bowls and trimming them down to the rim, you could throw a disk, cut the outside diameter of the disc to the inside diameter of the bowls, and trim away.

 

 

Good luck,

Pres

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One more little trick and I do this often with no problems, wait to cut the pot from the batt and do an initial trim right side up if for any design reason you want to trim the top, sides or even the inside. Then cut the piece free and finish trimming with any of the other methods. One more technique I use especially on pieces with small tops is to throw a heavy chuck with fresh clay on the wheel to fit my needs and when done trimming I finish throwing the chuck and turn the chuck into my next pot.

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Hi RonSa.  I like to trim down to the rim on bowls as well.  I think it gives a more uniform look.  Some glazes, in fact, look a little different on trimmed vs untrimmed surfaces, especially with grogged clay.  I do get the best vacuum when the pot is fairly moist, but I must be a bit heavy handed since I've ended up with a slight but noticeable slump on the inside of the bowl.  I have the most consistent results when I use the giffen grip for all but the last inch, then take the bowl off the grip (or switch wheels), remove the grip and finish the rim with a lip dip and vacuum seal.  I know this would be far too fussy for production pottery, but it works for me.

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I usually stick mine to the wheel head - a just damp wheel - damp sponge run around the pot rim a couple of times - centre on wheel and tap down as firmly as you can without distorting the pot - if I can turn the wheel by holding the pot I know it's stuck well enough to trim - the rim will almost certainly need a touch up with a sponge when you've finished.

 

If the clay is too hard or soft to stick I'll make a clay chuck and fit the pot on that, (that's how I was taught to do it).

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It looks like my clay was too dry. My studio is a 5 minute drive from where we live. We typically get there about 10ish and leave 2-3ish and our thrown clay from the day before dries a bit too much.

 

Today I placed what I threw into a closed cardboard box in hopes that this will slow down the drying

 

ronsa, if you have dried it beyond perfect for trimming, put the pot inside a plastic grocery bag with a sort of wet sponge.  not touching the pot, but in some container that will keep the liquid from touching the pot.  you just want to humidify the thing.  it might be fine the next day.

 

This worked well to soften up the clay and when I applied a little water on the lip trimming went a lot smoother.

 

I didn't find my roll neoprene that Min suggested to try, but I found a few compressible rubber blankets that are used on printing presses, These guys have a sticky back which makes mounting on the wheel head pretty simple. This worked reasonably well and I didn't have to dampen the lip of the bowl.  I plan on making a bunch of MDO bats and I'll dedicate one for the rubber blanket and I'll draw some concentric circles to aid in centering. Right now we have 4 bats for the two of us and we've been wiring them off a hump. We quickly learned that you can't have too many bats.

 

I like the idea that a few of you mentioned about throwing a disc on the wheel and mount the item on the soft clay so I can trim right down to the edge. I'm going to give that a try tomorrow.

 

Pres, once I get the other things made that we need for our new studio I may make a griffin grip and give it a try.

 

Thanks to all for your suggestions

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It looks like my clay was too dry. My studio is a 5 minute drive from where we live. We typically get there about 10ish and leave 2-3ish and our thrown clay from the day before dries a bit too much.

 

Today I placed what I threw into a closed cardboard box in hopes that this will slow down the drying

 

ronsa, if you have dried it beyond perfect for trimming, put the pot inside a plastic grocery bag with a sort of wet sponge.  not touching the pot, but in some container that will keep the liquid from touching the pot.  you just want to humidify the thing.  it might be fine the next day.

 

This worked well to soften up the clay and when I applied a little water on the lip trimming went a lot smoother.

 

I didn't find my roll neoprene that Min suggested to try, but I found a few compressible rubber blankets that are used on printing presses, These guys have a sticky back which makes mounting on the wheel head pretty simple. This worked reasonably well and I didn't have to dampen the lip of the bowl.  I plan on making a bunch of MDO bats and I'll dedicate one for the rubber blanket and I'll draw some concentric circles to aid in centering. Right now we have 4 bats for the two of us and we've been wiring them off a hump. We quickly learned that you can't have too many bats.

 

I like the idea that a few of you mentioned about throwing a disc on the wheel and mount the item on the soft clay so I can trim right down to the edge. I'm going to give that a try tomorrow.

 

Pres, once I get the other things made that we need for our new studio I may make a griffin grip and give it a try.

 

Thanks to all for your suggestions

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I made a bat on some roofers felt by spray gluing down a thin piece of foam on it and drawing on some concentric circles as it spun around.  It works really well for bowls as long as they're heavy enough or wide enough.  Next one I'll use denser foam.  

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It looks like my clay was too dry. My studio is a 5 minute drive from where we live. We typically get there about 10ish and leave 2-3ish and our thrown clay from the day before dries a bit too much.

 

 

I have a bun rack bought from restaurant supply house that has a zippered plastic cover. Stands about 5 feet and couple feet wide and deep. Cut 6 3/4 plywood shelves and it holds tons of pots and slows down drying when I want to. To further stop drying I cover pots with plastic and pretty much slows drying to a crwal. It cost $120 and is also on wheels so can easily be moved around the studio. I also use it (per Mark C) to put handled pots for the first day.

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Stephan, I have something similar. Its a cart with 24 shelves, 6 shelves on each corner, where each shelve has its own hardboard shelves and holds a full case of paper (10 reams of 8-1/2x11). Its on wheels. So far the boxes seem to be working to slow down the drying a bit. Plastic bags does slow the drying a bit to much.

 

Thanks for your input.

 

ronfire, I'm having trouble visualizing how your setup looks. Are you using the wood block in place of clay?

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