[Kohaku]

On a whim today, I decided to throw a whole mess of vessels to use as glaze testers. (Yes- there are more efficient ways to make glaze test pieces!).

I don't know that I'd ever tried to trim anything with that particular size/shape (more or less like a tall shot glass). Proper nightmare! Between the lack of mass and the high center of gravity, the slightest 'grab' of my tool to the clay and the vessel would want to go flying.

Out of 50 vessels, I lost twelve, and two went flying clear across the room. The dog stuck its head in and nearly got brained.

Thing is- I can't think of a better way to do this. Some kind of chuck? Any suggestions?

[Kabe]

Kohaku, on 06 November 2012 - 08:52 PM, said:

On a whim today, I decided to throw a whole mess of vessels to use as glaze testers. (Yes- there are more efficient ways to make glaze test pieces!).

I don't know that I'd ever tried to trim anything with that particular size/shape (more or less like a tall shot glass). Proper nightmare! Between the lack of mass and the high center of gravity, the slightest 'grab' of my tool to the clay and the vessel would want to go flying.

Out of 50 vessels, I lost twelve, and two went flying clear across the room. The dog stuck its head in and nearly got brained.

Thing is- I can't think of a better way to do this. Some kind of chuck? Any suggestions?

You can throw a centered cone, like when you first center your clay. Make it tall enough and small enough to set your vessels onto and you can use that to trim you work. Cover it with Plastic food wrap so it does not stick to you green clay. You can take the plastic back off if you need to adjust the size to fit your bowl. There are probably better way to do it but that works for me. Happy firing Kabe
We would hate to have you abducted by the Humane society for braining your dog.
I think small vessels are great test tool. I have started to throw all my glaze mixing bowls, cups large enough to hold 100 gram of glaze and a mixer beater. Part of it is because it is fun to have all these home made test cups and secondly I can use them to test glaze combinations. Like double dip rims. I number my glazes and put the number of the combination on the bottom of the cup with a wet mixture of red Iron oxide and bentonite with a small brush. Say glaze 101/402 that way if I want to repeat it It is easy to find. Plus it is good practice at throwing things the same size..

[oldlady]

i have done these same shapes for glaze tests. how are you throwing them that they even need trimming? if you make the pot tall and thin enough you can "trim" them as you finish the throwing. similar to making a mug with an untrimmed bottom. that last pass of the tool at the bottom can remove enough clay to make them have even walls and bottom.

[neilestrick]

I trim a foot onto every pot I make. I have a series of bisque fired chucks in various sizes to accomodate just about anything I make.

[Kohaku]

oldlady, on 06 November 2012 - 07:08 PM, said:

i have done these same shapes for glaze tests. how are you throwing them that they even need trimming? if you make the pot tall and thin enough you can "trim" them as you finish the throwing. similar to making a mug with an untrimmed bottom. that last pass of the tool at the bottom can remove enough clay to make them have even walls and bottom.

I'm throwing off the hump, taking the vessels off using a blade. This leaves some significant clay on the bottom, which I'd rather trim if possible. Heck, I'm 'into' feet (although not in a Quentin Tarantino sense).

I like the idea of throwing and bisqueing a series of chucks- I may go that route.

[spoggy]

Kohaku, on 07 November 2012 - 12:52 PM, said:

On a whim today, I decided to throw a whole mess of vessels to use as glaze testers. (Yes- there are more efficient ways to make glaze test pieces!).

I don't know that I'd ever tried to trim anything with that particular size/shape (more or less like a tall shot glass). Proper nightmare! Between the lack of mass and the high center of gravity, the slightest 'grab' of my tool to the clay and the vessel would want to go flying.

Out of 50 vessels, I lost twelve, and two went flying clear across the room. The dog stuck its head in and nearly got brained.

Thing is- I can't think of a better way to do this. Some kind of chuck? Any suggestions?

For an instant chuck you may have a fired pot already that you can use. But in future trim the test pots on the wheel with a tool before cutting off wheel head, so minimal trimming at leather hard stage, is needed if at all.

[Lucille Oka]

I make small vessels for testing also. I don't use a chuck (not that I couldn't use one now and then) but what I do is wait hours before I trim. I let the vessels dry a bit, and then I press a thick coil of clay around the upside down vessel to lock them centered on the wheel head.

Oftentimes a finger holding down the center of the vessel as it spins can keep it from flying off the wheel.

Sometimes I only have to dampen the bat and the lip which helps the vessel stay put. I also give each vessel a foot and a trough to catch potentially runny glazes. I also trim the foot with the wheel spinning slowly using various tools.

[Pres]

Kohaku, on 06 November 2012 - 08:52 PM, said:

On a whim today, I decided to throw a whole mess of vessels to use as glaze testers. (Yes- there are more efficient ways to make glaze test pieces!).

I don't know that I'd ever tried to trim anything with that particular size/shape (more or less like a tall shot glass). Proper nightmare! Between the lack of mass and the high center of gravity, the slightest 'grab' of my tool to the clay and the vessel would want to go flying.

Out of 50 vessels, I lost twelve, and two went flying clear across the room. The dog stuck its head in and nearly got brained.

Thing is- I can't think of a better way to do this. Some kind of chuck? Any suggestions?

I throw chalices in two pieces. The cups I trim on the GG, but the stems I trim in a thrown cylinder-thick. I trim all of the stems first, then as each cup is trimmed on GG I center the stem on and join. The thrown cylinder always gets thrown into a large jar or vase after the trimming is done.

When face with trimming something very small, I just create a cone off a hump, rib it, and start trimming. After trimming all pieces rib the hump and start throwing.

[Diane Puckett]

I recently saw this technique in a video, but I cannot remember who is was. They had made a chuck which was basically a bottle with a narrow neck and slightly flaired lip. The chuck was bisqued. When they needed to trim pots, they would first center the chuck on the wheel, sticking it in place with coils of clay. A smaller clay coil was securely placed around the lip of the chuck. The pot to be trimmed was placed on the chuck, with the clay coil on the lip of the chuck holding it in place. From what I remember, they used this technique to avoid distorting the opening on a teapot.

After spending much of today trimming glaze test cups, I think I need to make one of those chucks. Thanks for triggering my memory!

[perkolator]

Griffin Grip works wonders for items like this

[Kohaku]

perkolator, on 07 November 2012 - 02:26 PM, said:

Griffin Grip works wonders for items like this

Not in this case. The base holders were too low for the center of gravity, and the extensions held the vessels right where I wanted to do my trimming.

In general, I'm all about the G.G. For this specific application, however, I think the idea of a thrown cone (covered in saran wrap) sounds like the best odds. I'll be trying tomorrow.

[Pres]

Kohaku, on 07 November 2012 - 08:56 PM, said:

perkolator, on 07 November 2012 - 02:26 PM, said:

Griffin Grip works wonders for items like this

Not in this case. The base holders were too low for the center of gravity, and the extensions held the vessels right where I wanted to do my trimming.

In general, I'm all about the G.G. For this specific application, however, I think the idea of a thrown cone (covered in saran wrap) sounds like the best odds. I'll be trying tomorrow.

I often use a 2-3 inch thick circle of foam under the pot on the GG. This allows the sliders to hold down the foam, and the rods and pads to hold the pot. I did not think it would work in this instance-too close.

[Idaho Potter]

Before owning a Giffin Grip, I used various sized chucks. I always made the chucks double ended--different shapes--so I could use whichever end suited the piece to be trimmed. One problem after awhile was that the chucks became so dry sitting around waiting to be used, that I had a hard time getting the pot to stay in place. Now, I wash the dust off the chuck (chuck is no longer dry) which makes the clay wads stick in place and everything works just fine. As much as I love my GG, I make things that do not fit it, so back to chucks.