Ultimate sharp test

TheOne45 said:
I see Mr. ronbowusmc gave us a nice bone to chew.



The burr could be aligned with the apex so you won't feel it with your fingers. It will shave and slice tomato but as soon as you hit a harder material (like pine cutting board) the burr will fold and there goes the sharpness.
In this case the BESS tester would show there is a burr. The burr will fold over when hitting the wire.

But; what test can you do if you don't have a BESS tester? Apparently ''I can't feel the burr with my fingers'' test is not very reliable. How about paper test? This aligned burr can also cut paper if it can shave and cut tomato.
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As an indicator/help for me when I am establishing an edge during a build is to cut up cardboard boxes. Then afterwards I go into my final clean up and sharpening....
 
cudgee said:
A good magnification device preferably with an inbuilt light.
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I do have 60x loupe with inbuilt light and sometimes I can't see the burr but I know it's there. If I drag the edge a few times across pine or spruce wood the knife won't cut news print across the grains smoothly.
But if I deburr the edge properly I can shave and whittle oak wood and the knife will cut any paper in any direction after that.
 
I recall reading an interview with Phil Hartsfield about how he finished his sharpening to eliminate the bur. He said he would cut thick cardboard with every knife after sharpening to ensure there was no bur at the apex. Not sure how accurate or true it is, but his knives were definitely sharp!
 
navman said:
I recall reading an interview with Phil Hartsfield about how he finished his sharpening to eliminate the bur. He said he would cut thick cardboard with every knife after sharpening to ensure there was no bur at the apex. Not sure how accurate or true it is, but his knives were definitely sharp!
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It has helped me.
 
navman said:
I recall reading an interview with Phil Hartsfield about how he finished his sharpening to eliminate the bur. He said he would cut thick cardboard with every knife after sharpening to ensure there was no bur at the apex.
Click to expand...

Was he cutting the cardboard to remove the burr?
 
TheOne45 said:
I do have 60x loupe with inbuilt light and sometimes I can't see the burr but I know it's there. If I drag the edge a few times across pine or spruce wood the knife won't cut news print across the grains smoothly.
But if I deburr the edge properly I can shave and whittle oak wood and the knife will cut any paper in any direction after that.
Click to expand...
I know exactly what you mean, when you have properly deburred, the knife will slice paper with nearly a silent swoosh sound. You know straight away, but if there is even the slightest burr still there, it just doesn't sound the same. The burr, the bane of sharpeners. :rolleyes:
 
cudgee said:
I know exactly what you mean, when you have properly deburred, the knife will slice paper with nearly a silent swoosh sound.
Click to expand...
Well, sort of. I sharpened my PF719 to have a nice smooth edge and indeed it goes through the paper like there is no paper.
But usually I like toothy edges with a bite. You know, the edge bites in your fingers when doing three finger test. There is no burr (after wood whittling test) and the knife shaves and cuts paper cross grain but it makes this sound you can hear those small teeth biting the paper.
Such edge won't do a push cut 90 degrees cross fibers through news print with his own weight but it will shave and aggressively bite in anything.
Cliff Stamp made a video sharpening a knife on a very rough stone (#36 grid or similar) which is used to refresh/straighten sharpening stones. That's an edge it can chew through anything.
 
Try holding a page from a phone book vertically from the top of the page in front of you. Try seeing how far away from your hand you can push cut (without cheating) from the top of the page on down. The last I checked, Gunmike1 was able to get 6 inches.
 
TheOne45 said:
I see Mr. ronbowusmc gave us a nice bone to chew.



The burr could be aligned with the apex so you won't feel it with your fingers. It will shave and slice tomato but as soon as you hit a harder material (like pine cutting board) the burr will fold and there goes the sharpness.
In this case the BESS tester would show there is a burr. The burr will fold over when hitting the wire.

But; what test can you do if you don't have a BESS tester? Apparently ''I can't feel the burr with my fingers'' test is not very reliable. How about paper test? This aligned burr can also cut paper if it can shave and cut tomato.
Click to expand...
Yes and. If you have a pretty good idea of how your steel and sharpening method are going to interact, then that is not that big of a deal. I'm pretty sure I can't get a burr aligned like that free hand, and even if I could, I'd be noticing something on the finishing strop passes, in fact, I usually do notice the asymmetry at that point, but it gets corrected by the paste.
 
gadgetgeek said:
Yes and. If you have a pretty good idea of how your steel and sharpening method are going to interact, then that is not that big of a deal. I'm pretty sure I can't get a burr aligned like that free hand, and even if I could, I'd be noticing something on the finishing strop passes, in fact, I usually do notice the asymmetry at that point, but it gets corrected by the paste.
Click to expand...
I see. I somehow missed you are using strop at the end of sharpening.
 
Crag the Brewer said:
I think so, it's pretty abrasive. And the slicing motion might wear down burrs and catch points.
Click to expand...
Interesting approach.
I have somehow reversed approach. I strop at the end of the sharpening and then I cut some wood. If there is a burr it will fold or partially tear off. Then I do a paper test cross grains. If the knife stutters or tear the paper I strop some more till the edge is burr free.
 
TheOne45 said:
Interesting approach.
I have somehow reversed approach. I strop at the end of the sharpening and then I cut some wood. If there is a burr it will fold or partially tear off. Then I do a paper test cross grains. If the knife stutters or tear the paper I strop some more till the edge is burr free.
Click to expand...

I finish off every knife on a large Gossman steel. It's slightly more aggressive than stropping. It makes a huge difference after diamond plates and stones.

With paper, cardboard, and occasionally hardwood crosscuts.
But I finish on steel
 
Crag the Brewer said:
I finish off every knife on a large Gossman steel.
Click to expand...

I tried micro bevel a few times. I did it a few times on the same diamond plate I was sharpening and a few times I did it on finer diamond plate. It technically works but somehow I don't like a micro bevel concept.
I also tried all sorts of loaded strops - cork, wood, cardboard and jeans. They work but I didn't like the feedback. Loaded leather strop gives me the best feeling.

I've seen the results of steeling on ribbed and smooth steel on SEM images but I never tried it. I somehow don't like the idea of dragging the edge against metal.
 
TheOne45 said:
I tried micro bevel a few times. I did it a few times on the same diamond plate I was sharpening and a few times I did it on finer diamond plate. It technically works but somehow I don't like a micro bevel concept.
I also tried all sorts of loaded strops - cork, wood, cardboard and jeans. They work but I didn't like the feedback. Loaded leather strop gives me the best feeling.

I've seen the results of steeling on ribbed and smooth steel on SEM images but I never tried it. I somehow don't like the idea of dragging the edge against metal.
Click to expand...

From what I've read, Scott's steel isn't so much burnishing the edge.... It apparently takes tiny tiny shavings off?

I tend to use very Hard heat treatments, and it still works with steel treated to 64HRC

I hand grind, hand sharpen my blades.
So without fixtures my edges are going to be convex.

On my most recent EDC experiment, for myself, I attempted to grind a chisel edge. It was from 8670 treated at 60HRC.

I couldn't keep the true chisel edge free of developing a burr in use. I think that steel needs a harder edge for a chisel geometry.

I added a tiny micro bevel on the flat side. Just a few swipes on the stone. It has helped tremendously. And it's not terribly visible.
Worked good.
 
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