Trimming Wheel Thrown Work

[Plattypus]

Hi everyone,

 

I guess you would call me an advanced beginner... I have had some throwing success lately but when it comes to trimming I sometimes feel like I ruin them. The bottoms become uneven and I also sometimes get this repetitive grooving... is it called "chattering"? Anyway I just made my decent casserole uneven!!! Very frustrating.... any ideas on what I might be doing wrong? I'm using a Giffen grip and a Dolan 310 trimming tool...

[Deb Evans]

Sorry, I'm not a fan of the grip except when it comes to really uneven rims like pitchers or carved rims.

Anyway... all you need is some foam and a wood bat = glue a foam disk ( 2 inches thick, 1 inch shorter in diameter than the bat), center it and glue it to wood bat. then take a sharpe pen and draw circles - like a bulls eye every 1 inch going out from the center. Make sure your bat is drilled to fit wheel.

To use - just put the pot on, center it - gently, very slow, use index finger of 1 hand on the center of the pot to stabilize, other hand has the trim tool. Can be used for lefty or righty!

note - invest in some good steel trim tools like dolans, kimpers need to be sharpened and they wear out fast.

 

 

The problem w' the grip is that the piece has to be perfect and not everyone's pot are even.

I tell students - if you want perfect and even - go to walmart!

 

The chattering you're getting = pots a bit too dry, so trim a bit earlier.

and no high speed!

 

 

I like to finish by going over trim area w/ a rib so that the trim marks are elemenated.

 

This trim bat has been used by students for 15 years and still going strong.

What's nice is that your rim doesn't flatten out.

Hope this helps,

clayfully

Deb

[Username]

Sharpen your trimming tool.

[Plattypus]

Sorry, I'm not a fan of the grip except when it comes to really uneven rims like pitchers or carved rims.

Anyway... all you need is some foam and a wood bat = glue a foam disk ( 2 inches thick, 1 inch shorter in diameter than the bat), center it and glue it to wood bat. then take a sharpe pen and draw circles - like a bulls eye every 1 inch going out from the center. Make sure your bat is drilled to fit wheel.

To use - just put the pot on, center it - gently, very slow, use index finger of 1 hand on the center of the pot to stabilize, other hand has the trim tool. Can be used for lefty or righty!

note - invest in some good steel trim tools like dolans, kimpers need to be sharpened and they wear out fast.

 

 

The problem w' the grip is that the piece has to be perfect and not everyone's pot are even.

I tell students - if you want perfect and even - go to walmart!

 

The chattering you're getting = pots a bit too dry, so trim a bit earlier.

and no high speed!

 

 

I like to finish by going over trim area w/ a rib so that the trim marks are elemenated.

 

This trim bat has been used by students for 15 years and still going strong.

What's nice is that your rim doesn't flatten out.

Hope this helps,

clayfully

Deb

 

 

I hear what you are saying about the grip. However, this has happened to me when I am using luggs of clay and centering by tracing with a pin tool also... as far as dryness goes, I was concerned it was too wet. It was quite moist. Can anyone give advice on sharpening the tool?

[Seasoned Warrior]

Sorry, I'm not a fan of the grip except when it comes to really uneven rims like pitchers or carved rims.

Anyway... all you need is some foam and a wood bat = glue a foam disk ( 2 inches thick, 1 inch shorter in diameter than the bat), center it and glue it to wood bat. then take a sharpe pen and draw circles - like a bulls eye every 1 inch going out from the center. Make sure your bat is drilled to fit wheel.

To use - just put the pot on, center it - gently, very slow, use index finger of 1 hand on the center of the pot to stabilize, other hand has the trim tool. Can be used for lefty or righty!

note - invest in some good steel trim tools like dolans, kimpers need to be sharpened and they wear out fast.

 

 

The problem w' the grip is that the piece has to be perfect and not everyone's pot are even.

I tell students - if you want perfect and even - go to walmart!

 

The chattering you're getting = pots a bit too dry, so trim a bit earlier.

and no high speed!

 

 

I like to finish by going over trim area w/ a rib so that the trim marks are elemenated.

 

This trim bat has been used by students for 15 years and still going strong.

What's nice is that your rim doesn't flatten out.

Hope this helps,

clayfully

Deb

 

 

I hear what you are saying about the grip. However, this has happened to me when I am using luggs of clay and centering by tracing with a pin tool also... as far as dryness goes, I was concerned it was too wet. It was quite moist. Can anyone give advice on sharpening the tool?

 

 

Emery paper wrapped around a pencil or other suitable stick would help a lot or you can take an piece of fine emery paper an glue it to a piece of glass or a tile. I like to use fine wet-dry emery paper in about a 440 grit and use it wet, it stays open and cuts better. Be careful it can make the tool extremely sharp. Rub the tool across the emery papaer the same as if you were taking a cut with the tool that way you will not develop a burr. Chatter marks indicate that the tool is not cutting easily. I personally love my Gffen Grip and use it for trimming all the time, it is so handy to have and holds much more firmly than foam.

 

Regards,

Charles

[Plattypus]

Sorry, I'm not a fan of the grip except when it comes to really uneven rims like pitchers or carved rims.

Anyway... all you need is some foam and a wood bat = glue a foam disk ( 2 inches thick, 1 inch shorter in diameter than the bat), center it and glue it to wood bat. then take a sharpe pen and draw circles - like a bulls eye every 1 inch going out from the center. Make sure your bat is drilled to fit wheel.

To use - just put the pot on, center it - gently, very slow, use index finger of 1 hand on the center of the pot to stabilize, other hand has the trim tool. Can be used for lefty or righty!

note - invest in some good steel trim tools like dolans, kimpers need to be sharpened and they wear out fast.

 

 

The problem w' the grip is that the piece has to be perfect and not everyone's pot are even.

I tell students - if you want perfect and even - go to walmart!

 

The chattering you're getting = pots a bit too dry, so trim a bit earlier.

and no high speed!

 

 

I like to finish by going over trim area w/ a rib so that the trim marks are elemenated.

 

This trim bat has been used by students for 15 years and still going strong.

What's nice is that your rim doesn't flatten out.

Hope this helps,

clayfully

Deb

 

 

I hear what you are saying about the grip. However, this has happened to me when I am using luggs of clay and centering by tracing with a pin tool also... as far as dryness goes, I was concerned it was too wet. It was quite moist. Can anyone give advice on sharpening the tool?

 

 

Emery paper wrapped around a pencil or other suitable stick would help a lot or you can take an piece of fine emery paper an glue it to a piece of glass or a tile. I like to use fine wet-dry emery paper in about a 440 grit and use it wet, it stays open and cuts better. Be careful it can make the tool extremely sharp. Rub the tool across the emery papaer the same as if you were taking a cut with the tool that way you will not develop a burr. Chatter marks indicate that the tool is not cutting easily. I personally love my Gffen Grip and use it for trimming all the time, it is so handy to have and holds much more firmly than foam.

 

Regards,

Charles

 

 

Thank you so much for the responses... I really appreciate them and I will sharpen my tools!

[~janie]

I have had pots become uneven when I don't get them centered just right. A little off makes a lot of difference. I am interested in trying the foam. This is the first I have heard of that. I learn so much here!

[GEP]

I have two other suggestions, not sure if they apply to you.

 

If you are using a new Dolan after using less expensive trim tools before (such as a Kemper or a Blue Heron), the Dolan blades are made of a different material and behave differently. When I first started using Dolans I had a chattering problem too. It helps to adjust the angle of the tool, i.e. hold the handle of the tool more tangentially to the pot with the blade more perpendicular to the pot. But I don't think that's the complete answer. The complete answer for me was "time," after a while my body adjusted to the new tool and the chattering went away.

 

And this one contradicts what others have said, but I think it's possible the tool is "too sharp" for you. It is cutting your pot too quickly, and you are not braced enough for it, and therefore it bounces. So I would also suggest using less pressure and bracing yourself more.

 

Of course, this doesn't mean I'm right and others are wrong, this is just another suggestion for you to try.

 

I do agree with everyone who said slow down your wheel speed.

 

Mea

[Plattypus]

I have two other suggestions, not sure if they apply to you.

 

If you are using a new Dolan after using less expensive trim tools before (such as a Kemper or a Blue Heron), the Dolan blades are made of a different material and behave differently. When I first started using Dolans I had a chattering problem too. It helps to adjust the angle of the tool, i.e. hold the handle of the tool more tangentially to the pot with the blade more perpendicular to the pot. But I don't think that's the complete answer. The complete answer for me was "time," after a while my body adjusted to the new tool and the chattering went away.

 

And this one contradicts what others have said, but I think it's possible the tool is "too sharp" for you. It is cutting your pot too quickly, and you are not braced enough for it, and therefore it bounces. So I would also suggest using less pressure and bracing yourself more.

 

Of course, this doesn't mean I'm right and others are wrong, this is just another suggestion for you to try.

 

I do agree with everyone who said slow down your wheel speed.

 

Mea

 

 

Hi Mea, Your comments are very interesting... (and of course I already put a bit of effort into sharpening that Dolan, but haven't tried it yet)

 

I had a class a couple of years ago by a well respected potter. When I trim I hear her voice telling me to speed up so of course I always do... and I do feel like I am more successful with the cheaper tools... looks like I need to be more attentive to the variables and note wheel speed vs which tool etc... Thanks so much... I'll try looking at the angle with the Dolan.

[Pres]

Hi everyone,

 

I guess you would call me an advanced beginner... I have had some throwing success lately but when it comes to trimming I sometimes feel like I ruin them. The bottoms become uneven and I also sometimes get this repetitive grooving... is it called "chattering"? Anyway I just made my decent casserole uneven!!! Very frustrating.... any ideas on what I might be doing wrong? I'm using a Giffen grip and a Dolan 310 trimming tool...

 

 

I use a variety of trimming options when working. One of my first options is the Griffin Grip which I love in many cases. I have found that some of my work is held very well in the tool for trimming pitchers, bowls, plates, chalice bowls, and I even trim chalice stems with it. At other times I use the bat pad that I use with my wooden bats. I just soak it in a little water, stick it on the wheel head and finger nail a mark the diameter of my pot to be trimmed. place the pot on the pad and trim holding down with the thumb. Other times I just trim on the bare wheel head holding the pot down with an old lid pressed upside down with a dash of oil or hand cream inside. This allows me to hold down the pot and have little friction on the finger. I use this most often on irregular bowls and mug type forms.

 

A lot of times people make the mistake of not balancing the drying of a pot. This will often effect the trimming of the pot. I always turn pots upside down after initial set to help balance out. Also, it helps not to make thin rims on the pot. GGs can warp the pot if the rim is thin. Especially if you are trimming when the pot is turning cheese hard, which is a good time to do your trim.

 

Sharpening tools is easy with a dremel tool if the tool itself is placed in a vice. with a little practice you can get a clean straight edge, and sharpen the tool easily. Hint here is to use a fine rubber type polishing wheel instead of a grit wheel it will not eat up the tool. Takes a little longer, but works very well.

 

I make my own tools using hack saw blades and a torch. With a little heat, the blade can be bent to 90 then shaped with a grinder, and sharpened. This allows you to make tools with any sort of shape you want. I even have one with a foot ring bead in it.

[Username]

^{Sharpness is key in surgery and the tonsorial arts.}

[Plattypus]

^{Hi Plattypus,}

 

^{Sounds like you have all the right tools for success, they just need to be tweaked.}

^{First, what do YOU mean when you use the term “uneven?†To me this could mean a couple of things :}

• ^{The foot of the piece is not level, which causes the piece to have a tilt (the rim is not level) when you right it.}
• ^{The width of the foot rim is not consistent around the circumference.}

 

^{Which of these problems do you have, or do you mean something else?}

 

^{Dolan tools are great, they come sharp, and can be re-sharpened as necessary. The sharper the tool the better; I have tried, but failed, to come up with an application where a sharp tool is a detriment. Woodworking, Ceramics, cooking, the tonsorial arts, surgery, guillotining - all benefit from the sharpest tool available. Mankind has spent many, many, hours trying to understand sharpness and how to get it. There is a reason for this, and besides, sharpening takes time, material, labor. Why would Dolan and many other makers take so much effort to give their products a sharp edge if it was not necessary?}

^{There are a couple of ways to get the Dolan tools sharp :}

 

• ^{Send them back to Dolan for sharpening. If you have three or four of them, you can have them in rotation, where you use a couple while the other two are out at Dolan for sharpening. This is probably cost and time prohibitive.}
• ^{Do it yourself. It is not that hard, and the tools you buy for it can be used on other tools, like knives, chisels, axes, garden tools, etc.}

  ^{Using a wet stone (water or oil) or a diamond stone is a good way to sharpen them. One of the fastest ways to ruin a good blade on a trimming tool, knife, or chisel is to use a mechanical aid, such as a grinder, grinding stone in a drill, or the dreaded Dremel tool. These will remove too much material, and more to the detriment, will overheat the blade, removing the temper, and ruin the blade for good. You only need to remove 0.001†of material to achieve sharpness, this doesn’t require high speed tools.}

  ^{Use the wet/diamond stone, then strop on leather or a medium grain, dense wood like basswood, and you are good to go.}

  ^{To keep them sharp, you can do quick touch ups with diamond files like these :}

  ^{http://www.rockler.c...=diamond%20file}

   

  ^{I use these to dress my trimming tools WHILE I am trimming, for the best edge possible. They are pretty good, but are plastic backed, and will “dish†over time, making it harder to use.}

  ^{Find stones at :}

  ^{http://www.sharpeningsupplies.com}

  ^{I, like you , had many troubles with trimming until I found out I was not letting the clay dry enough, and my tools were too dull – I am VERY fussy about my (pot) feet, I like them as neat, tidy and precise as possible, and I had trouble getting there until I developed some patience and discipline about my tools. Now, I love to trim almost as much as throwing itself, and sometimes more.}

  ^{You will get there too!}

 

 

[Plattypus]

You raise a good point, Username. I meant the former in my post but I must admit that the latter is sometimes true. I haven't been working much and am trying to get back to it... Many of the pieces I trim belong to Middle School students using the wheel for the first time so my memory may be mixing with those. In general though, I think I have both issues. Thanks for your post.. it is not too often when surgery and the tonsorial arts are mentioned when I discuss pottery. Thanks for the chuckle and the advice :-)

[Guest JBaymore]

For another approach for trimming, maybe take a look at learning to use the Japanese kanna and umakaki trimming tools. I have been trimming about 99% with these types of tools for many, many years. When I give demos at workshops and in my college classes, people are usually amazed at the way they work.

 

The D shaped umakaki is a tool that most westerners are not familar with, but when they see it, they find it a pretty good solution for trimming the flat starting point on off-the-hump pieces. I also usually use it for the first passes on the sides of my large bowls (24"- 26" diameter) because it will take off large swaths very quickly.

 

Kanna take some getting used to, since they are supposed to be VERY sharp when used (I sharpen them before each trimming session with a diamond stone) so the contact angle between the cutting blade and the clay surface is very slight. They cut the clay, not drag and abrade it like so many common cheap American tools do.

 

Best part is kanna are not all that expensive. And a single one lasts a LONG time even with constant sharpening. They don't shatter if you drop them like some other expensive tools tend to do.

 

At first you will likely decide that they are absolutely uncontrollable...... but with a bit of practice...... you'll swear by them. Most people (including Dolan tool users) find that at first the kanna tool "dives" right into the clay, and will gouge out a single deep divot.

 

You can take off anything from hair-thin sheets to big chunks without any significant downward/inward "pressure" imparted into the piece. That allows you to trim very thin without deforming the leather-hard clay form if you so desire.

 

As has been discussed already, I too think sharpness is a key factor for a good trimming tool.

 

best,

 

..............john

[Pres]

For another approach for trimming, maybe take a look at learning to use the Japanese kanna and umakaki trimming tools. I have been trimming about 99% with these types of tools for many, many years. When I give demos at workshops and in my college classes, people are usually amazed at the way they work.

 

The D shaped umakaki is a tool that most westerners are not familar with, but when they see it, they find it a pretty good solution for trimming the flat starting point on off-the-hump pieces. I also usually use it for the first passes on the sides of my large bowls (24"- 26" diameter) because it will take off large swaths very quickly.

 

Kanna take some getting used to, since they are supposed to be VERY sharp when used (I sharpen them before each trimming session with a diamond stone) so the contact angle between the cutting blade and the clay surface is very slight. They cut the clay, not drag and abrade it like so many common cheap American tools do.

 

Best part is kanna are not all that expensive. And a single one lasts a LONG time even with constant sharpening. They don't shatter if you drop them like some other expensive tools tend to do.

 

At first you will likely decide that they are absolutely uncontrollable...... but with a bit of practice...... you'll swear by them. Most people (including Dolan tool users) find that at first the kanna tool "dives" right into the clay, and will gouge out a single deep divot.

 

You can take off anything from hair-thin sheets to big chunks without any significant downward/inward "pressure" imparted into the piece. That allows you to trim very thin without deforming the leather-hard clay form if you so desire.

 

As has been discussed already, I too think sharpness is a key factor for a good trimming tool.

 

best,

 

..............john

 

I was just finishing up some trimming, and noticed a few things that I do without even thinking about it. First off, I often have pots that are in various stages of dryness-especially this time of year since me garage is heated only by an electric heater. I noticed that I use sharp tools when working with the leather hard pots, taking of clay quickly, developing the form and then use a duller tool to smooth up the surface, and refine the form of the foot ring and base. When working with the pots that are cheese hard, I use the duller tools. I have a Dolan spade shape that is great for taking off clay quick, and then I use dull loop tools for finishing.

 

I always start by using a hack saw blade held across the center evenly with both hands to flatten the base, then proceed to the trimming. The hack saw works well with tooth side down in the beginning, and then the flat side to finish. They are cheap and will make a variety of L shaped trim tools those you call the "kanna". I have been using manufactured tools of this type for several years and prefer them to the loop tools due to their comfort and ease of sharpening. I think my first one was an old "Trim Jim" some of these are made with springy blades for chattering in a decorative manner, others-especially the Dolan's I have are very stable, and stiff-I prefer them.

[Deb Evans]

just to throw this idea out there. I use to trim by hand and sometimes was just faster than setting up trimming on the wheel.

just would sit down and carve w/knife, lightly sponge texture away at the end.