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David Kruk

Trimming A Foot For Bowls

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David Kruk    0

Greetings! This will be my first time posting, so I hope this question is relevant.

 

I was in the studio today doing some trimming. Trying to create a small foot, I ended up trimming too much and went through to the inside of the bowl. I tried to salvage it by bandaging it up with some more clay, hopefully it holds up.

Is there any way to tell at what point to stop trimming (taking into consideration the weight of the bowl)? I really like the aesthetic of a small foot and the visual effect of the bowl looking like it's hovering. However, I end up trimming too much when trying to achieve this effect.

Thanks!

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There are a couple of "tricks" that you will see people use, but the reality of the situation is that experience is your best friend, or practice rather. Some will tap on the pot to judge thickness, some will watch the quality of trimmings (more fluid trimmings=wetter clay->safe to trim, shorter stiffer trimmings=drier clay->exterior face of wall), there's probably a couple of other "tricks..."   The best way to know what to trim is to know the form you're trimming, and trim based on the landmarks available to you. The overall weight of a bowl should have a lot more to do with how you're throwing than how you're trimming. There's a lot more information packed into the walls of a bowl than the foot, especially in regards to weight.

 

I guess the answer is to spend time with the form before trimming, take a shot at it and evaluate afterwards. In the process of learning, don't be afraid to take a couple of shots at trimming.

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I agree with Colby, but...before trimming, you can stick a push pin, the kind for bulletin boards, through the bottom of the bowl from the inside. When you begin to feel the pin, you have trimmed enough. You can even stick another pin on the side if you are trimming there. Just make sure you smooth over the hole on the inside of the bowl. This technique can be good until you learn how to tell in other ways.

 

I also like small feet on bowls, but if feet on functional bowls are too narrow, the bowls tip over in use. Irritating with salad, even more so with soup.

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Biglou13    202

Practice, you must

Numerous the cylinders, must end up cut in half.

 

There is no fast track secret.

But scour the Internet and you tube. There are measuring systems

 

You could read the rest below, or stop,here and just re read and practice the first two lines.

 

I use needle tool to measure bottom and wall thickness,

Then place same measurements by marking clay on side and bottom.

I subtract , approx finished wall thickness an mark on side

This mark is absolute do not trim below this.

Then memorize shape of inside of bowl

Outside should match

With needle tool and bowl spinning mark approx foot size.

Then I first trim down to line at outside diameter. I begin tapping at this point to get a feel for thickness

Then I trim inside of foot to depth and diameter, tap check

Then trim and shape of bowl, tap check

Fine tune transition of bowl to foot, tap check

Clean it all up. Tap check

 

For now .Throw bottoms a little thick approx 1/2 inch, dry slowly

 

In actuality I needle check depth and make the marks, trim to depth, from there on its intuitive, and feel, after awhile you will know how thick your throw , how thick you trim. As of late ill needle check thickness then, fly by the seat of my pants and trim on pure blind faith. (Or just faith)

 

But above all practice, cut many in half, and keep,few to none

 

There is some saying about a thousand bowls.......

I'd like to add 1000 cylinders before those 1000 bowls....

(Im still working on my cylinders every time I throw, it's become 1medtitation, I will cheat and throw a bowl,every now and again)

 

 

Dave , welcome.

Tell us where you are from

Pottery experience

Pottery influences

Post images in gallery

Etc etx

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Chantay    101

When I need the thickness of the bottom of the pot to be pretty accurate I take several steps.  First, I have a very small needle tool.  I place a small ball of clay on to the tip of it.  With the pot sitting on a flat surface I push the tip of the needle tool through the bottom till I hit the hard surface beneath.  When I pull the needle tool back out I can see how far the little ball has slid up the needle.  I then use the needle tool to mark into a piece of clay that I keep on the edge of my splash pan so I can see the thickness of the bottom.  After several months of doing this I and getting a feel for the sound of thumping the clay I mostly "wing" it.  If I am having a hard time judging how far down I have trimmed I will lay a chop stick across the foot of the pot while it is still on the wheel.  Hope this helps.

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Benzine    610

Biglou, was that whole thing written in Haiku?

 

Great advice though. I use tapping, while I'm trimming, then I'll pick up the ware and tilt it back and forth in my hand, to feel the weight.

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Babs    386

Hit the trimming button at the top rhs of this forumand there are extensive discussion on this topic.

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Nancy S.    21

I hate to say it, because I hate to hear it, but it's really true:  Practice, practice, practice. The more bowls you throw, the more you'll get a feel for how thick your bottoms are, and the more you'll be comfortable with trimming.

 

I don't so much mind trimming, I just HATE centering!!

 

(FWIW, I have never had a bowl dry well when I've messed up the trimming...)

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Mark C.    1,807

This is an easy thing to learn.

In one day Throw 30 cereal bowls next day tap center and trim 30 cereal bowls and before you are done you will know how to tap center and where to stop trimming-its rteally that simple.

Cut a few on 1/2 to see what they look like as well.

Forget patching just cuck out any that are over trimmed.

Pots are not precious just throw more

If you do not have it mastered in 30 do another 30 until you do.

The needle tooling and pin pricks are all somewhat like a crutch and I suggest learning without them-and in the end you will just get it

one last note as to small feet-the best foot is one that feels right for each shape -sometimes overly small makes the bowl tipping as does wide makes them look heavy. Getting it right is an art.

Learning YOUR foot is key. I spent a year  on and off with my mentee on feet. In the end she owned her own foot and it worked and look great.

The only way is lots of feet under the bridge.

Mark

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JBaymore    1,432

But above all practice, cut many in half, and keep,few to none

 

There is some saying about a thousand bowls.......

I'd like to add 1000 cylinders before those 1000 bowls....

(Im still working on my cylinders every time I throw, it's become 1medtitation, I will cheat and throw a bowl,every now and again)

 

 

You have learned well. :)

 

best,

 

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

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JBaymore    1,432

Mark (and Lou) has (have) cut to the chase.

 

These are the 'hard things to say'.... we don't like to hear them...... but the thoughts are necessary.

 

There is no "magic".  You don't "play with clay" (had to get that line in there ;) ).... you work at it.  Put in a bit of work, and you'll see the rewards.

 

Early in your ceramic studies the "product" is not the tangible pieces that you happen to be able to produce.  The important product is the learning that takes place.  Amassing skills... one at a time.  It is nice to keep some stuff as a reminder of progress......... but focusing on the OBJECT at the goal is a bit of a mistake.  The learning is the goal... the object is the by-product of the learning. 

 

If you let the products become 'prescious' to you  ('Myyyyyy Preasiousssssssssss" )...... you will not tend to take risks with them..... and that can seriously impede learning.  One of my favorite "lines" in intermediate and advanced throwing classes is, "What happens if you hit it with a 2x4 ?"

 

best,

 

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

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Benzine    610

 

If you let the products become 'prescious' to you  ('Myyyyyy Preasiousssssssssss" )...... you will not tend to take risks with them..... and that can seriously impede learning.  One of my favorite "lines" in intermediate and advanced throwing classes is, "What happens if you hit it with a 2x4 ?"

 

best,

 

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

That's why after my throwing demo, Right before I cut the piece in half to illustrate consistent thickness, I preface it with saying "Now don't freak out". Even though the piece isn't their's, the feel so connected to it. I'll usually follow it with, "Sometime(s) you'll have to do something similar to your own."

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I just air on the side of caution and tell myself I meant to make it bottom heavy for stability  ;)

 

I find it useful like others have said to mark a line on the outside of the pot that shows where the bottom of the pot is and how far you can dig into the bottom.

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Welcome David!

 

I just learned another trick, from Antoinette Badenhorst: measure the thickness of the bowl in penetrating the wall with a toothpick. Then cut the toothpick to the wall thickness and stick that small piece into the bottom of your bowl. Now trimm until you hit the toothpick and then stop trimming....

 

And of course, practice, throw 1000 bowls and practice....

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GEP    863

When I trim a foot ring, I also like to measure the pot thickness with a needle tool first. I find this is a big time saver. I measure in three places: the outer edge of the foot ring, the inner edge of the foot ring, and the middle of the floor. Once I know these measurements, then I trim straight to the right answer. No hesitating or guessing, and no trimming through the pot.

 

A lot of the pots I make in multiples do not have foot rings, for those pots I skip the needle tool. Instead I eyeball the shape of the interior, then trim the exterior to match the shape of the interior. (my point is ... foot rings are not required, unless you want them.)

 

Anyhow, whether I'm measuring with a needle tool or not, I always gauge the "dentability," i.e. when the wall is the correct thickness, it can be dented with a press of your finger. I taught my students "when it's right you should be able to do this" then I'd make a big dent in the pot with my thumb. When everyone stopped gasping, I'd invite them all to dent my pot, so they know how it should feel. Then I explain how to check for dentability without making a visible dent ... press until you feel the wall begin to give, then stop, it will bounce back. I will also make sure to say "if you press and it still feels like a solid object, keep trimming."

 

This is similar to what others are saying above, teach potters that pots can be ruined and life goes on. It just means you get to make another one.

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schmism    21

I use a motion with a finger that is half a tap and half a press test as GEP mentioned.

 

My issue is as i throw once a week at a studio i take classes at,  I have to wrap all my wares in plastic to slow down drying.   As such due to thrown differences they will be a different dry states (while generally leather hard, some are softer and some are harder)   so its difficult to get an idea of the "right sound" with a tap test as the sound changes as the clay gets harder,   at the same time the press test can also be misleading.  But one thing is for sure,  the press test WILL tell you when your really close to breaking through if your stopping frequently enough to test.  It has saved several pieces for me in the past.

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Karen B    26

I sometimes use calipers on the wall of the bowl. Starting at the wall closest to the foot and slide up to the rim, I can see how much I need to remove. It gives me a good visual.

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Biglou13    202

Anyone ever use something like this.

 

Ultrasonic thickness gauge?

http://www.defelsko.com/utg/positectorutg.htm

 

When I was struggling with trimming I thought of it.

I even found some wide mouthed digital calipers.

 

I'm glad I didn't spend the cash. I finally figured it out old school style. Like the ancient potters before our time.

 

Don't get me wrong I'm not diss'n the technology...

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Min    783

I 100% agree with all the posts about practice, tapping and pressing the base. I can appreciate that there are times before you have perfected this that it's nice to have a pot with the proper weight.

 

Simple method using pencils and a tape measure here: http://ceramicartsdaily.org/clay-tools/pottery-trimming-tools/tips-for-trimming-bowls-on-the-pottery-wheel/

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PSC    54

I use the push test too. Just push lightly on the side or bottom and look for slight movement.

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Hi David,

 

Not to beat a dead horse, but practice is the best thing you can do for your trimming. The tap method that others have brought up is great when working on a new form, but once you've thrown and trimmed the same form a bunch of times, you'll just start to know how much you want/need to trim.

 

Here's a link to a video by Hsin Chuen Lin focused on achieving even thickness through trimming. He shows you how to make an easy DIY measuring tool that is more accurate (albeit more complicated) than basic calipers.

 

Cheers,

 

Chris

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