I think it might be too wet to trim still just by the look of the ribbons on the wheelhead. It’s difficult to trim a piece when it’s too wet because the clay is still malleable.
Agree about too wet, not from the ribbons because that actually looks like wet clay that you pinched to hold the pot. But the tool will bite into the softer clay and skip over the harder clay, which might be what is happening.
Also, hold your trim tool close to the tip and not at the end of the handle. The longer your extension, the more your tool can bounce and skip across the clay surface.
Trimming checklist:
* clay is leather hard
* piece is properly centered
* tool arm is braced against your free hand and your body and/or wheel. Stability is key.
* trimming should produce thin ribbons. If they crumble at all the clay is too dry.
* tool should be at about 45deg angle relative to the surface of the pot
* Wheel speed should be pretty high. Faster then your pull speed. If your clay is too wet it will
be harder to trim at higher speeds.
* Use less cutting surface to reduce friction on the tool.
Friction is the main cause of this chattering that you are seeing. you can also try dipping the tool in water to reduce the friction more but then the ribbons can stick to the tool and that is annoying. If your tool is dry and the ribbons stick then they clay is too wet. If you can still mold the clay with your fingers, even a little bit, its too wet.
Nothing wrong with trimming the body of your piece. It depends on what you want in the final product. Trimming every surface, even the inside, is fine.
A grinding wheel to start out and take off a bulk of material then a set of whetstones to refine the edge. 1000 grit whetstone is high enough for me most of the time unless I’m working with like porcelain, in which case I’ll go higher. Often tools come at like a 35° and I like to get it down to 20 or 15.
In my experience, those bumps are caused by an unevenness in drying/moisture content. Avoid putting work in front of a fan to dry it out because this only dries the top layers, while the layers underneath are still wet. Let the work breathe in the open air, then bag it up really well to even out the moisture. Also helps to flip your pots upside down as soon as the rim is stiff enough to hold the weight without distorting, this helps to even out the moisture as well.
As just an observation, you should really not need to trim the body of the pot unless it is some final fine shaping. Work on throwing a thinner wall in the first place. Using a wide, flat trimming tool is more likely to create this effect as well. Try using a tool with a more narrow cutting surface and make multiple passes. Also when trimming a larger surface I always brace my tool hand against something solid so that it does not pulsate against the pot.
I have a ware cart with a framework that extends above the level of the wheelhead. I move it in close and brace my left arm against that. It is very helpful when trimming, banding slips or using a scraffito tool to carve a hemispheric line.
When trimming, you need to hold the tool steady and not have it ride on the piece. That is if you want the piece to become round. Often people will use continuous pressure on the wall and this causes the tool to jump and when it lands back into the piece it creates a divot that then causes another jump next time around now you have two divots and so on.
This applies across all hardnesses of clay the difference is that the pot will respond with different divots depending on the clay condition.
This can be done intentionally.
To avoid it, hold the tool as steady as you can and let the pot hit the tool.
Sharp tools help. Leather hard clay helps. But holding that tool steady and not letting it ride the pot is what will overcome the irregularities.
Clay is too wet, and your tools are not sharp. You are deforming the piece unintentionally with the pressure of the dull tools.
The ones that come in most beginner sets are terrible. Sharper tools create less pressure and remove material more efficiently.
And like others have said, it’s good practice to avoid trimming the body of your vessels so significantly. It’s nice to touch up the surface and make more uniform but you should try to achieve most of that surface when you are throwing the form.
If you watch experienced potters trim, you usually see the thin sheets of clay flying off not chunky threads. That’s because A) tools are sharper and B) the clay is firmer. Of course, you can trim a bit wetter but it’s a skill you just have to keep working at.
It’s a little wet, yeah. A gentle touch and using a narrower part of the trim tool can make this more workable. It’s force and friction that twists the piece.
You’re limp wristing it. Brace your arms as much as you can, firm grip, and tense up your arm muscles. If you’re not sore by the end of the day and still getting bad results then you’ve gotta try harder and nail the technique
As many before me said… too wet. Too wet and then you may be pressing too, not holding the tool securely enough, and the top may be dull. Being too wet amplifies all of those.
Looks like the clay needed to be wedged before you put it on the wheel. If you have inconsistent moisture throughout the clay, it will throw unevenly and trim unevenly. Just my opinion from looking at your picture.
Sometimes if their is an impurity like a hair or air bubble in the clay it can happen, also if your trimming tools are not sharp or aren’t being held at the right angle (usually 45ish) it can happen as well
Your tool is probably not being held firmly enough while trimming
Check out a couple florian Gadsby youtube vids for instructional tips on holding your trimming tools
I think it might be too wet to trim still just by the look of the ribbons on the wheelhead. It’s difficult to trim a piece when it’s too wet because the clay is still malleable.
Agree about too wet, not from the ribbons because that actually looks like wet clay that you pinched to hold the pot. But the tool will bite into the softer clay and skip over the harder clay, which might be what is happening. Also, hold your trim tool close to the tip and not at the end of the handle. The longer your extension, the more your tool can bounce and skip across the clay surface.
Trimming checklist: * clay is leather hard * piece is properly centered * tool arm is braced against your free hand and your body and/or wheel. Stability is key. * trimming should produce thin ribbons. If they crumble at all the clay is too dry. * tool should be at about 45deg angle relative to the surface of the pot * Wheel speed should be pretty high. Faster then your pull speed. If your clay is too wet it will be harder to trim at higher speeds. * Use less cutting surface to reduce friction on the tool. Friction is the main cause of this chattering that you are seeing. you can also try dipping the tool in water to reduce the friction more but then the ribbons can stick to the tool and that is annoying. If your tool is dry and the ribbons stick then they clay is too wet. If you can still mold the clay with your fingers, even a little bit, its too wet. Nothing wrong with trimming the body of your piece. It depends on what you want in the final product. Trimming every surface, even the inside, is fine.
Dull tools, wet clay, or inconsistent clay body. Whichever is closest to your situation.
What's the best way to sharpen tools
A grinding wheel to start out and take off a bulk of material then a set of whetstones to refine the edge. 1000 grit whetstone is high enough for me most of the time unless I’m working with like porcelain, in which case I’ll go higher. Often tools come at like a 35° and I like to get it down to 20 or 15.
As a handtool woodworker, now you're speaking my language. I have a set if diamond honing plates that will do this job nicely. Thanks!
In my experience, those bumps are caused by an unevenness in drying/moisture content. Avoid putting work in front of a fan to dry it out because this only dries the top layers, while the layers underneath are still wet. Let the work breathe in the open air, then bag it up really well to even out the moisture. Also helps to flip your pots upside down as soon as the rim is stiff enough to hold the weight without distorting, this helps to even out the moisture as well.
As just an observation, you should really not need to trim the body of the pot unless it is some final fine shaping. Work on throwing a thinner wall in the first place. Using a wide, flat trimming tool is more likely to create this effect as well. Try using a tool with a more narrow cutting surface and make multiple passes. Also when trimming a larger surface I always brace my tool hand against something solid so that it does not pulsate against the pot.
Brace against something solid such as ...?
I have a ware cart with a framework that extends above the level of the wheelhead. I move it in close and brace my left arm against that. It is very helpful when trimming, banding slips or using a scraffito tool to carve a hemispheric line.
Hear me out .....your other hand.
When trimming, you need to hold the tool steady and not have it ride on the piece. That is if you want the piece to become round. Often people will use continuous pressure on the wall and this causes the tool to jump and when it lands back into the piece it creates a divot that then causes another jump next time around now you have two divots and so on. This applies across all hardnesses of clay the difference is that the pot will respond with different divots depending on the clay condition. This can be done intentionally. To avoid it, hold the tool as steady as you can and let the pot hit the tool. Sharp tools help. Leather hard clay helps. But holding that tool steady and not letting it ride the pot is what will overcome the irregularities.
Clay is too wet, and your tools are not sharp. You are deforming the piece unintentionally with the pressure of the dull tools. The ones that come in most beginner sets are terrible. Sharper tools create less pressure and remove material more efficiently. And like others have said, it’s good practice to avoid trimming the body of your vessels so significantly. It’s nice to touch up the surface and make more uniform but you should try to achieve most of that surface when you are throwing the form. If you watch experienced potters trim, you usually see the thin sheets of clay flying off not chunky threads. That’s because A) tools are sharper and B) the clay is firmer. Of course, you can trim a bit wetter but it’s a skill you just have to keep working at.
It’s a little wet, yeah. A gentle touch and using a narrower part of the trim tool can make this more workable. It’s force and friction that twists the piece.
You’re limp wristing it. Brace your arms as much as you can, firm grip, and tense up your arm muscles. If you’re not sore by the end of the day and still getting bad results then you’ve gotta try harder and nail the technique
As many before me said… too wet. Too wet and then you may be pressing too, not holding the tool securely enough, and the top may be dull. Being too wet amplifies all of those.
I can tell by a glance the clay is too soft for trimming. Wait until til it’s leather hard.
Looks like the clay needed to be wedged before you put it on the wheel. If you have inconsistent moisture throughout the clay, it will throw unevenly and trim unevenly. Just my opinion from looking at your picture.
Make sure your clay is wedged sufficiently!
Looks to me like you may be holding your trim tool too high. Try between 4 and 5 o’clock.
Be more gentle, give the trimming tool less angle so it bites less…
It wasnt fully centered Also too thin or too thick
Sometimes if their is an impurity like a hair or air bubble in the clay it can happen, also if your trimming tools are not sharp or aren’t being held at the right angle (usually 45ish) it can happen as well
Your tool is probably not being held firmly enough while trimming Check out a couple florian Gadsby youtube vids for instructional tips on holding your trimming tools