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Rebekah Krieger

Trimming Issues

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I have been making long neck bottles and vases.  I have been unable to get them to stay put when trimming. The bottom of the vase is larger than the top, so they tend to not hold steady even if I use clay to hold it still. I have thrown a "chuck" But since the clay is soft on the chuck, it doesn't seem strong enough to keep the form still, top-heavy when upside down.  I also have trouble with the chuck clay sticking too much to the pot that I am trying to trim.  I have tried using stoneware to mount the white porcelain so it has a stronger clay body to hold it up, but I have the same issues and it leaves ugly brown marks on my porcelain what require scraping and sponging off…. 

 

Does anyone have a solution? 

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What about doing the trimming by under cutting at the base while it is on the bat, before wiring it off?

I use one of those metal triangular trimmers on the long rod and wood handle.  set it on the bat at the bottom of the bottle and let it do the work.  Makes a nice shadow line and takes away the extra clay at the bottom edge.

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I have been doing a little "pre trim" with the wood throwing tool but not fully. I was hoping to get a foot and to remove clay from the bottom center of the pot.  

 

I feel like a cheater when I don't fully trim the bottom and I just "thumb off" the edges of a pre trimmed pot… It's hard to break that mindset.  

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Have you tried trimming when the chuck is leather hard?  If I'm on the ball, throw a chuck before I throw anything, and time it so that the chuck is as hard if not a little harder than the pieces I need to trim.  If I'm having trouble getting things to stick, I'll put down fresh clay buttons of the same body to hold things in place.

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Have you tried trimming when the chuck is leather hard?  If I'm on the ball, throw a chuck before I throw anything, and time it so that the chuck is as hard if not a little harder than the pieces I need to trim.  If I'm having trouble getting things to stick, I'll put down fresh clay buttons of the same body to hold things in place.

No- this is a great idea. The only problem I have with that is I usually have no idea what the dimensions of my pots will be until they are made.  I would love to be able to throw something that looks like a drawn out plan with measurements.  But It is a goal to aim for

Celia UK likes this

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I suggest learning to tap center 1st but you can do this without that

the way to trim a form other than the actual bottom is  pat bottom of pot so its very slight concave or flat but not domed on bottom

wet wheel head with a mist and tap center and let clay grab surface (dry slightly)-then trim 

I have done pitchers this way for 40 years.

Mark

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When you throw a throwing chuck, make it pretty hefty. Works well when the bottle is leather hard. Dry the top edge of the chuck with a dry sponge before placing the bottle upside down in the chuck.  Some bottles can be trimmed when upright and held on the wheel head with water. However those formed with steep undercut are best trimmed upside down.

 

I made a chuck for my griffin grip out of plumbing parts, PVC pipe, flange, rubber seal and foam seat ring. It works really well for my chalice stems, and would do the same for bottles. And not griffins are not evil, and every tool has a place, as the griffin does for me.

clay lover and Darcy Kane like this

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as far as a gif fen grip learn to center by tapping (look this up on web)

learn the good skills 1st

after you are very proficient and you need to trim lots of things at once then and only then get the giffin

If you do it now it will be a crutch and you will never learn the right way.

Mark

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I can tap center and trim a bowl or mug upside down. I am having trouble with gravity when my items are either tall or bottom heavy (like a long neck bottle or small spout) (because inverted they are top heavy when trimming)  I think the leather hard chuck and the idea of making a thicker more heavy duty chuck might help. 

 

 

These items were particularly hard for me to trim, I am so used to making bowls and mugs, I am re learning how to trim shapes like this.  

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post-19612-0-16289900-1398826870_thumb.jpg

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Those items can trim easy with the wet the wheel head and trim upright when they stick to the head after tap centering.

Unless you need to trim the bottom and if thats the case I'm in the camp that says make some chucks of various sizes and use them

For me get the bottom thickness right and tap center them on wet wheel head then trim sides near bottom if thats where it needs trimming.

Mark

Rebekah Krieger likes this

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Tall tapered Bisque chucks with thick round lip.  Will allow narrower bottle to slide in deeper to hold better.   If you use bats you could dedicate one to trimming only and leave chuck on it to speed up future centering.

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You can leave the bottles centered on your bat, then trim the sides of the bottle while it is still right-side-up. Then you only need to trim the very bottom of the pot upside-down. This is how I approach tall cylinders and small-neck pots. The triangular metal trimmer that claylover mentions is very useful for this.

 

Giffin grip is a great tool. It is not a substitute for clay skills. For me it only saves me the time of putting down clay wads to hold down my pots for trimming. It's method of holding small-neck pots upside-down is very effective, but nothing more than a chuck that can be adjusted for size.

Marcia Selsor likes this

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You could improvise by making a chuck from a coffer can or bucket, center it secure it with clay, put a thick coil on the rim and trim it to evenly support you pots. Making chucks in the long run is a good idea and good to have the right tools when you nee them. Mea's trimming upright is also a good time saver.

 

 

Marcia

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I use a bisqued chuck of sorts. I usually have several tall, vase or utensil holder shaped items waiting for glaze. I just use some clay to center the holder (one deep enough for the neck of the bottle), then put the bottle in, stabilize it with a clay ring, and trim the bottom of

the bottle. I'd just do a picture, but I'm not at my shop :)

 

Lee

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I keep several bisqued chucks in the studio of various sizes so I always have one when I need one. Just center up the chuck, anchor it with clay lugs, and center up the pot in the chuck. To hold the pot steady you have to put a lot of pressure on it while you trim. To keep from pushing through the pot with your finger, put a Snapple lid on the pot and push on it. Use 1 finger and let the lid spin with the pot. Make sure the shoulder of the pot is firm enough that it won't collapse or get marred by the chuck. Keep your speed up while trimming. If the wheel is going too slow the pot will be more likely to go off center.

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I want to make pots, not chucks.  I am happy to use a Giffen Grip, it keeps the rims of my pots smooth like I threw them and aids in making more pots.  I don't see it as a crutch, anymore that plugging in the wheel rather than using a kick wheel.  To each his, or in this case, her, own. :-)

 

Why not check the bottom depth closely before raising the walls and then trim the outside when you finish throwing ?  It would not give you a foot ring, but would take care of bottom weight and I don't usually see fr's on bottles.

Pres and Rebekah Krieger like this

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I made a chuck for my griffin grip out of plumbing parts, PVC pipe, flange, rubber seal and foam seat ring. It works really well for my chalice stems, and would do the same for bottles. And not griffins are not evil, and every tool has a place, as the griffin does for me.

 

Hey Pres, could I bug you for a photo of that PVC chuck for griffin grip?

clay lover likes this

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Similar to Pres and Marcia, But I use firm plastic plantpots with a ring of cloth and sponge to soften where the pot meets the "chuck" ,  large no. of pots, use this within the Giffen grip.

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When i throw a chuck i make it thick then i put wet strips of newspaper on the chuck rim, and place the pot on the newspaper covered chuck. After trimming the pot i remove the paper and throw a pot out of the thrown chuck.

 

Also you can make a flared(think of the shape of three mile island neclear towers) thick walled bottomless cylinder as a chuck, bisque and permenantly center mount it to a bat ...i keep saying i am going to do this but never get around to it.

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I made a chuck for my griffin grip out of plumbing parts, PVC pipe, flange, rubber seal and foam seat ring. It works really well for my chalice stems, and would do the same for bottles. And not griffins are not evil, and every tool has a place, as the griffin does for me.

 

Hey Pres, could I bug you for a photo of that PVC chuck for griffin grip?

 

I have included a couple of pics of the chuck on the wheel. I did not have any stems to trim of late so you can't see that yet. However, for those of you that use the GG I think it explains itself. I find that it works better for me using the base pads to hold it in place rather than longer stems and pillows. The parts are simple, flange, Pipe head donut, and a soft rubber seal. The pipe I saw using a cutoff to keep it square resting on the GG top with the flange around it. There is not glue, so you could take it apart and put different lengths of pipe in. This is all 3" pipe. I hope you can understand how it is used, and it probably would work for bottles, candle holders, and other long stemmed objects. As I throw off the hump and don't always get an even cut, this allows me to even up the base with a hack saw blade held perpendicular to the base of the stem pressing evenly across, in a matter of seconds it will even out the base.

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post-894-0-23069700-1399001148_thumb.jpg

post-894-0-03586600-1399001158_thumb.jpg

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