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docweathers

Sharpening Loop Trimming Tools

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I have an over supply of dull loop trimming tools. I have previously used a small diamond impregnated metal sharpening tool. This is very slow and laborious, particularly on the non straight tools. Has anyone come up with an easier way to sharpen these gadgets?

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Hey,

I've tried sharpening them from the outside, and from the inside not very successfully. Sometimes they're easier to sharpen as you go...before they become too dull. Sometime you can take Emory cloth, wrap it around a dowel to sand the inside.. The metal blade is only a ribbon that gets dull in one area, so once I took the blade from the handle, shortened the blade to get a fresh surface. This all was done on the larger loop tools.

 

On the long slender trimming tools I use the dowel and sand paper to sharpen the loop end. Sometimes I remove the blades and re-use the wooden handles. To remove the small blades, run a bic lighter flame around the end for 3 seconds then pull out...they seem to be glued in. I have taken disposable razors apart and attached the blades to the handle... But they're flimsy, and one mistake will slice a finger or an opposable thumb. To make an incising tool from this long handled(8.25) inch tool, cut the blade into, heat one side and remove the blade, ànd sharpen the other one left. I made a point to mention the length since I use tools of known lengths to measure the heights of cups and other cylinders!!

 

 

Most wooden handles are used for homemade needle tools. Just drill a small hole and insert a sharpened welding rod or sharpened and shortened car antenna. I knew if I didn't put "shortened" someone would say they're having trouble using a 3 foot needle tool! :)

 

I have thought about making changeable blades using thin band saw blades but haven't so far.

 

I trim a lot, and judge wall thickness from applying pressure on trimmed leather hard surfaces, and the tone from tapping the side, top to bottom. Not too thick nor thin!!

 

Good luck, as we all have to decide to sharpen or buy new all the time!

 

See ya,

Alabama

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Buying a really good loop tool is what I have found to work best at keeping an edge (Dolan or Kemper Pro) still a pain to sharpen with a file. I did start making my own trim tools out of hacksaw blades since I have an abundance of used ones from work. I saw Hsin-Chuen Lin video on YouTube

and I am sold on making and using them. They do not stay as sharp as long but I can sharpen 10 or so on the bench grinder and be good for a while. I also like how fine of a ribbon I can make.  

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Mark / Matthew

 

So how many tons of clay can be trimmed with carbide loop tools before having them sharpened? I have seen the price tags on these and wondered are they worth it? What brand do you use?

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what, if you have never used a Bison tool, you have been missing something special.  

 

i would love to find some kind of metal worker who can reproduce the old, very old tool i use for carving.  the closest i can come today is a nib from Speedball that they sell for scratchboard.  it is only adequate, needs to be shaped like an eagle's claw and as sharp at the point.  clay just rolls off the curved center section and the lines are precise.

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I have been using special made  ones that are double ended and look like a R2 kemper 6 inch ribbon tool.They are made by Phil at Bison tool in Las Vegas.

He makes his line of tools and mine are not in that line.

I sent him the tool I needed as a much up-he has made 3 for me so I always have a new one.I have worn out 3 of them in about 10-12 years

I used to buy Kemper R2 buy the gross (40% off ) and go thru that in a few years.These carbide tools are not for everyone because they are fragile and when its not in my hand its in a plastic tube next to trim wheel. If you drop stuff avoid these tools.One drop and its broke at 50$ per end.

I have been working with 10 tons a year approx and a tool lasts about 2-3 years unless you drop it.

Then its worn out and needs a new end

I only suggest using these if you trim lots of clay-If you are a hobbist they are not worth the expense 

I work with porcelain 

You can buy them direct from Xiem with exchangeable tips although the choices are limited on shapes

I have given a few of these  to other potters.

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I bought 2 bison trimming tools for my birthday last year. Spent around $150 all together. Probably the best money I have spent on tools since I started. I use them every day. They are hands down worth every penny. They seem as sharp as the day I got them and I have trimmed a lot of pots with them. 

 

I used to hate trimming my metal tools. Got so old. I used a diamond round file, and it took a while.

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Suppose it takes 5 minutes to sharpen a trimming tool, which is pretty quick if you're planning to do a good job. In reality I would probably spend closer to 10 minutes to get it done right, so it cuts without leaving lines. But let's stick with 5 minutes for this argument. In that amount of time I can throw 3 mugs or 3 tumblers or 2 bud vases, or 1 medium vase, etc, which comes out to about $22 worth of production done in the amount of time it takes to sharpen a $5 tool. Even for a $14 Dolan it's not worth the time. Throw it away and buy a new one. Support another business.

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Suppose it takes 5 minutes to sharpen a trimming tool, which is pretty quick if you're planning to do a good job. In reality I would probably spend closer to 10 minutes to get it done right, so it cuts without leaving lines. But let's stick with 5 minutes for this argument. In that amount of time I can throw 3 mugs or 3 tumblers or 2 bud vases, or 1 medium vase, etc, which comes out to about $22 worth of production done in the amount of time it takes to sharpen a $5 tool. Even for a $14 Dolan it's not worth the time. Throw it away and buy a new one. Support another business.

 

This is how I feel. Excellent way to put it.

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Bison tools are very very nice. They fit in the hand beautifully and are a joy to use. They allow you to trim stiffer pieces and to a thinner wall. How long they last will depend on how you hard you trim and if your clay has grog in it. This year I switched to Newcomb 6 which is finely grogged --it is hard on the edges.

 

I do most of the rough trimming with Kemper steel loops and the finishing with the Bison. My plan is to continue using them and donate the worn out ones to the open studio.

 

I'll agree and disagree with Neil. It may not be "worth the time" but I mentally cannot throw all day long. Doing a mundane thing (reclaiming, sharpening, cleaning) is better than doing nothing. And if you pile up a dozen dull tools into a box, the task will happen fast enough to be time-valuable. If you can resharpen twelve $10 tools in an hour... that is equivalent to earning $120/hr.

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One thing that has not been mentioned is when I went thru many many grosses (actually more than that) of Kemper R2 6 inch ribbon tools I never sharpened them as they wore thru (wore out first). I always wore out the loop end before the straight end. I trim say bowls on the outsides with the loop and do the inner foot with the straight side

I still wear out my bison loop end first . I never was a 8 inch tool man always 6 inch.

I have steel trim tools hanging on a spinning tie rack by my trim wheel but they are NEVER used.

 

As a production potter time is worth $ so bison tools add up in so many ways for me. Using one tool vs burning thru grosses of them.

That whats happens when you have lots of clay to trim.Three # 5 gallon buckets week of trimmings is the norm here.

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I use to sharpen the classroom kemper trimming tools. For my own, the loop ends wore out first.Still putting an edge on them did help their function. I am going to try my diamond core drill bit and see hot that goes. There is always jewelers files.

Marcia

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At Marcia's suggestion,  have tried using my bench grinder with a 600 grit wheel. It works very well. The cut is very smooth and slow enough that you feel like you have good control but fast enough to get the job done quickly.

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It sounds like you have found a solution that works for you. Here is another method that may help, I do make my own tools and sharpen them.

 

Sharpening will be a lot faster with multiple grits. I would use at least three grits Coarse, Medium, and Fine. In my shop I would use 100 180 and 220. If I was feeling ambitious the fourth would be a coarse fast cutting jewelers rouge compound applied to a hard felt buffing wheel.

 

Set the new bevel with  a coarse grit power sander, 80 to 100 grit, this operation with practice, should take one to two seconds.

A disk sander for the flat areas. For the curved areas a small Dremel drum sander attachment mounted in a drill press for control. Have a can of water close to dip keep the tool cool after each grinding operation.

 

Once the bevel is established

You progress to a medium 100 to 220 grit sand paper, Your goal in each of the succeeding steps is to remove the coarse scratches from the previous step. Ten to twenty swipes starting with the coarsest grit should do it. With practice this should take less than a minute or two. The fine grit sand paper could be 220 to 600 grit. As the grit gets finer you hand work doubles. If you took ten swipes with your medium grit it will take twenty swipes over the fine grit to remove the medium grit scratches.

 

Use 3M super 77 adhesive to attach sand paper to a tempered glass panel, a flat ceramic tile, or a flat cast iron table for the flat areas. Glue sand paper to a dowel rod for the curved areas.

 

A swage block that matches the contour of your tool can be made from wood and will make sharpening a specific shape quick. Your sandpaper glues to the shape cut from a nice hardwood like Hard Rock Maple. With some imagination a swage block with various contours could be made from pressing various shapes into clay and then fire the clay to make it sturdy.

 

As an example:

for a 1/4 round 3/8"  swage, you would drill out a piece of hard wood to 3/8". Quarter the wood so that 1/4th of the drilled radius remains then glue sand paper to your new swage that matches the 3/8" outside diameter perfectly.

 

The final stage would be a buffer with Jewelers rouge. I would use 4" to 6" felt disk because the edge on a clay tool is not very wide. The felt buffer disks can be used on a buffer or a drill press with a proper mandrell. A sewn fabric disk would work on a high speed buffer, but it may rip the tool from your hand easier. Dremel makes small drum type felt buffer tips for the curved areas if you have trouble using a regular buffer disk.

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what, if you have never used a Bison tool, you have been missing something special.  

 

i would love to find some kind of metal worker who can reproduce the old, very old tool i use for carving.  the closest i can come today is a nib from Speedball that they sell for scratchboard.  it is only adequate, needs to be shaped like an eagle's claw and as sharp at the point.  clay just rolls off the curved center section and the lines are precise.

I use some old Gare clean up tools that sounded similar to what your describing but the blade is rather wide. I looked at Georgies website because I knew Kemper made a version of the tool I use and I think the dcl, dcs, and k26 look like a more "claw like" version of the blade in various sizes. Hopefully helpful? http://www.georgies.com/gcc-shop-tool-ceramic.shtml

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thank you, twinrocks, there are several tools that look somewhat like what i want.  the problem is that none of them offer the double curve, the hook point that does the cutting and the edge that is curved inward so the clay peels off in long curls.    if i could find a vise that could be set to a narrow wedge instead of parallel faces, i could make one from one of these curved, pointed trimming tools.

 

the speedball imitation is shown in the pen holder in the lower section.  if i look for it's number this post will disappear forever.  maybe i can enter it and edit.  did that, it is called scratch and lift.

 

if i could find a narrow, pointed bullet and slice it lengthwise, i think i would have 2 of them.

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Ah, I see. A dapping iron might do it, but that could also dull the edge at the same time. The k27 looks like it might be shaped more like what you are describing but it's hard to tell from photos, the Cls is sort of spoon like but might be too wide. I sometimes use a cheap set of Japanese block printing gouges for scgraffito, they are pretty much the same as a Speedball linoleum cutter, but the blades are heartier in my opinion & they hone easily with a slip strop. Might be a pleasing alternative to try before finding a custom tool?

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