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Toothy edge - Scotch brite belt(1)
#1
I used worn Blaze 120 grit(about 15 degree), and Super fine scotch brite belt.(higher degree) 

   

   

Center sharpness: 197, 301, 209 BESS.(Average is 236 BESS)

Fail
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#2
I've found that 120 grit is just too gnarly.  Because I enjoy a toothy edge I've played with down to 40 grit and have found that below 150 becomes problematic.  I know you said "well worn" but FWIW that's my experience.

Looking at your images I see obvious LOW which will drastically reduce sharpness where LOW exists.  The yellow arrow in the image looks to be free of LOW, but the red arrows show where it exists.  See the difference?  LOW is present on both your images.

   

Give the blade a few more light passes on the Scotch-Brite.  That's where the SB belt shines.  It is can actually remove it.  Too much SB will dull the edge so it takes a bit of practice but it does work and if you figure it out it works well.  It can grab onto that crap and lift it off the bevel.

Then give it a couple of light passes with the rough side of a leather belt.  You may find the sharpness numbers drop by 100 points or more.  I haven't taken the time to figure out exactly why the leather works so well, but it can and does.  Maybe it's removing existing burr and cleaning the edge or maybe straightening the edge or maybe both.

I am not seeking sub 100 sharpness and anything 100-150 is fine.  You know, edges less than 150 are so thin they won't be that way after chopping even a couple of carrots, so anything in that range is fine with me.  For me the simple procedure of sharpening with a 150 Cubitron, deburr with Scotch-Brite and finish with a few passes on leather routinely produces edges in that range and generally closer to 100.

While it's interesting and fun, I no longer chase super sharp edges because they don't last with even a little use.  I try to make a useful edge.  I really like sharp, but super sharp to me is more of a challenge and hobby than sharpening for practical use.  

A fun exercise is to get an edge just as sharp as you possible can.  Take 4 or 5 sharpness readings and then let the knife sit overnight without using it.  Then the next day, take sharpness readings again.  Automagically it will be considerable duller.  Then let it sit abound for a week and do the same.  You will probably be surprised by the results.  
Please see: http://bessex.com/forum/showthread.php?t...84#pid3684

I would be interested in hear your results after finishing the edge with the leather belt and any thoughts you may have on why it works.
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#3
grepper.

I think the fresh ceramic belt is better for making toothy edge. But this time, I tried worn belt.

And I know the effect of clean leather belt but I don't have it now. I'll order it soon.

BTW, where can I buy 1x42 150 cubitron? Wasn't it discontinued?
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#4
The 150 grit 1x42 Cubitron belts were discontinued, but it appears they are back in stock here:

https://www.rshughes.com/p/3M-Cubitron-7...111_67951/

Smile

If you don't have a clean leather belt use whatever you have on hand.  I mean, the idea is that you just don't want to use too much fine abrasive so as to avoid removing tooth.  It's possible to use a bit of soap and water and scrub the belt with a brush to remove compound buildup.  Once it's dry, use a bit of oil to condition the belt again so it won't crack and is supple again. 

The leather belt I'm currently using still has white color from a few years ago.  I was making a polished edge so I put some Tormek PA-70 on it.  The PA-70 is AO, 1-3 micron and I'm quite sure any remaining abrasive has long since worn out and has very little if any effect.  Nonetheless it still has some white discoloring but I just use it and don't worry.  It seems to work.

This stuff isn't rocket science.  You have a microscope so you can check the edge and see if whatever procedure you are using is smoothing the teeth or not.  You just gotta play around and check the results so you understand what's happening.  You'll get it.
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#5
Thank you, grepper. I'll keep trying. Smile
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#6
My two cents here Sharpco and that's all it's worth because you're already conversing with the gold-standard of the toothy edge, Grepper. I say use your thumb across the edge of your toothy sharpening efforts in order to judge success. The sensation is unmistakable to me when compared to the feel of polished edges. For kitchen knives, I use the 150 cubitron and then the finest grade Scotch Brite belt available. This results in 140 edge sharpness for me while Grepper usually finds himself around a 100 on a regular basis.  Grepper is just more meticulous about the whole process than me. I say this because if he is meticulous at all, he's more meticulous than me. I bring a dozen knives from our kitchen in to the shop here every three or four months and a half hour later they're done. Once back home, I warn Joan that they've just been sharpened but that warning doesn't seem to reduce her reliance on band-aids.

The magic of the Scotch Brite is simply this; it removes the LOW and the balance of the burr while preserving the tooth and does all this expeditiously.

Even at 140 - the knife is sharper than any brand new blade the home chef has ever experienced and the tooth - oh, the tooth, - makes any pork loin or tomato tremble with fear.
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#7
Mike.

Grepper use worn very fine SB belt.(blue) Do you use same thing? The finest SB belt is super fine. It's grey.
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#8
To tell you the truth Sharpco, I couldn't even testify to the fact that the belt we use is Scotch Brite brand. It's blue,  looks like a Scotch Brite, smells like a Scotch Brite and tastes like a Scotch Brite but the name Scotch Brite isn't on the catalog page or the product. We bought it from McMaster Carr on-line https://www.mcmaster.com/catalog/125/2726 and is described as follows:

Nylon Mesh Cushioned Sanding Belts
Very Fine Grade—For Extra-Smooth Finish
1"  42"  Blue  Aluminum Oxide  Nylon Mesh  Steel, Wood  47505A116  14.29


I'm sure that we put some wear on this belt prior to using it for burr removal by simply holding a steel bar against it ,while running,  for an extended period of time. Then use a light touch, flipping the knife four or five times and voila' - no burr with tooth remaining.

We did try a coarser grade and it was Scotch Brite brand and while certainly removing the burr and preserving the tooth - it turned out edges in the 220 - 240 area. While most people who frequent this forum would turn up their noses at 220, in my opinion, if every knife, in every home chef's knife drawer was 220 and toothy -   there would never be another knife sharpening gizmo or machine sold - but lots of band aids.
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#9
I just sharpened a Henckels paring knife.  I think I sharpened it before a long time ago, but it was really dull.  Took quite a few passes on the A100 belt (180 grit) before I finally got a full length burr on both sides.  

I deburred with a VF scotchbrite (blue) and then bare rough leather.  Edge seemed pretty good.  Sliced phonebook decently.  But I decided to take it to the BESS.  I knew half way through I had a problem.  Too much force was required.  Sure enough, it scored a 500!  Jeez...

So I slid my thumbnail down the side of the blade towards the edge, feeling for a burr.  Sure enough I found, not a normal tiny burr, but a "step" that my thumbnail bumped over.  I'm pretty sure this would have looked like Line Of Weld under a microscope.  Back to the VFSB.  This time I felt each time with the thumbnail slide.  I checked both sides, did some more shallow angle strokes on both sides and... I could no longer detect any "shelf".  I considered doing leather, but I could not see any burr or feel it.  Let's try the BESS again:  150!  Really?  Let's try another spot (nearer to the tip):  155.  Ok, I'm satisfied with that.  Smile

Apparently I need to spend more time with the VFSB and less with the leather.  This steel is pretty soft, so I'll keep that in mind in the future.  Harder steels will probably behave differently.

I'm very happy to have discovered this combination of tools, measurement, and advice (Hi Grepper!).  

Brian.
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#10
Hi back Brian. Smile  Good job!  It sounds like your sharpening technique is good too as evidenced by consistent readings along the edge.  A 5 point variance is extremely good.   I’m always happy with a 150 edge.  IMHO, 150 is about perfect for a general purpose blade.  It’s my feeling that much sharper doesn’t buy much because the edge is so thin that it will roll more easily.  

I have little doubt that the ridge you described is indeed what has been here described was indeed LOW.  And, you are correct that leather won’t remove it.  Once I saw it under the microscope I did a LOT of experimenting on the best way to remove it.  That LOW pile of crud metal is well stuck to the bevel and most materials just ride over it.  Scotch-Brite and its ilk was the only material that reliably grabbed on to it and lifted if from the edge.  

http://bessex.com/forum/showthread.php?t...an#pid4341

FWIW, LOW can be worn away with fine abrasives, but that will remove the toothy edge under it.  More importantly, fine abrasives can actually sharpen the LOW to a very sharp edge.  The problem with that is that LOW is crap for metal and the edge will dull immediately with little effort.  Even if the desired end result is a polished edge, it’s important to remove the LOW before finishing with the fine abrasive polishing operation.

I deburred with a VF scotchbrite (blue) and then bare rough leather.  Edge seemed pretty good.  Sliced phonebook decently.  But I decided to take it to the BESS.  I knew half way through I had a problem.  Too much force was required.  Sure enough, it scored a 500!  Jeez...

LOW can be deceptive, but checking the sharpness told the story.  Unless the LOW has been polished it has a rough surface and will cut paper well because it can grab and tear the paper fibers when the paper is sliced.  LOW is weak junk metal and the edge won’t last and but I’ve been fooled by paper slicing too.  

Apparently I need to spend more time with the VFSB and less with the leather.  This steel is pretty soft, so I'll keep that in mind in the future.  Harder steels will probably behave differently.

Every knife is seems to be a different beast when it comes to deburring.  Bevel angle, size of the burr and hardness will all effect deburring.  I never know exactly what to expect and just take it one knife at a time.  

I’ve found that deburring with S-B is a bit of an art form and takes some practice.  It’s easy to dull the edge with it, but once mastered it works extremely well and consistently even where other methods fail and/or take longer.  

Just guessing Mr. Brian, but a couple of passes on each side with the leather at sharpening angel may have turned that 150 edge to 130.  I always finish with a couple passes with leather at sharpening angle and then a few firm swipes on my jeans against my thigh.  More often than not the edge gets a bit sharper.  I think what’s going on is that it cleans things up a bit and straightens the edge after the S-B.

Really happy to hear the tools and methods are working well for you!  Once you see it work and get the hang of it the process makes more sense and becomes easier and quicker.  Very cool.
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