Sharpening Gurus: Need Help

I

ICCW

Joined
Aug 6, 2010
Messages
46
I'm having problems in my quest for the sharpest possible blade. I take a coarsely sharpened factory edge, sharpen it using a DMT aligner system or even the Spyderco Sharpmaker. I sharpen the blade from coarse to fine, then strop the edge until it literally shines. Once I'm done, however, the shiny, sharp, razor-like edge just isn't as sharp as an edge created with a coarse stone or even the factory edge.

Am I doing something wrong? Any help would be greatly appreciated.
 
Also, sometimes a very fine edge will feel less sharp at some tasks because it doesn't have any teeth to "grab" the material being cut. For some cutting tasks, a 300 grit edge works the best and feels the sharpest.
 
Also, make sure you are holding the correct angle when you strop and don't apply too much pressure when you strop.
 
Sorry if it is obvious in the text, but i don't see what kind of knife you are sharpening. Could be the knife and not you.

Sometimes, the knife just doesn't have a correct heat treat and won't hold an edge.

Have you tried doing the same thing on more than one knife with the same results?
 
res1cue said:
When you start with your coarsest hone, are you getting a burr on each side?
Click to expand...

Raising a burr has nothing to do with sharpness.
If the edge isn't chipped or deformed, raising a burr only wastes metal.
A few leading edge strokes are all that's needed the vast majority of the time.
 
What exactly do you mean by "isn't as sharp"? How well does it cut newsprint? Will it shave? If you rest the egde on your fingernail, can you slide the blade across your nail or does it bite and want to stay put?

The factory edges are usually 120 grit, very coarse, and will feel very aggressive if you are touching the edge with your fingertips. A polished edge won't feel quite like that, but it should still feel sharp.

The things to look at are: is there a burr remaining on the edge, and is the stropping rounding over the edge (too high angle and/or too much pressure).

Burrs can be hard to see, but even tiny ones can make the edge feel dull. To get rid of a burr, you make alternating edge-leading strokes on the stone with light pressure, gradually reducing the pressure to zero. Intermittently during this, I run the edge with moderate pressure over a piece of hardwood. I do this on each stone as I move through the grits. On the final stone, I do this and then at the very end, I increase the angle just slightly (like 1 or 2 degrees) for a few alternating strokes, using very light pressure. This creates a tiny micro bevel and removes any remaining burr.

As for stropping, are you using a hard-backed strop or something floppy like a belt? If the leather gives too much, it will curl around the edge as you strop and round the apex of the edge. You can control this by the amount of pressure you use, and less is more. You also want to strop at the same angle, or even slightly less, than you use on your sharpening stones. If you raise the spine up too much, you can round the edge.
 
Buck_110 said:
Raising a burr has nothing to do with sharpness.
If the edge isn't chipped or deformed, raising a burr only wastes metal.
A few leading edge strokes are all that's needed the vast majority of the time.
Click to expand...

I heartily disagree, and here's why.

For someone who's trying to learn the process, and also trying figure out if the edge is ready (fully apexed), the burr is the best indicator, by far. From my own struggles in learning how to sharpen, I finally figured out most of my troubles were in not attempting (or even seeing the need) to raise a burr first. I never fully apexed my edges. Even now, with a lot more 'experience' under my belt, I still see a very justifiable benefit in making absolutely sure the burr's raised, before moving on. This forum is full of posts from others who've had difficulty in figuring out 'what's wrong' with their blade/process/technique/etc. And so many times, few or none of them are verifying burr formation, and therefore not attaining it either. Making a 'sharp' edge gets infinitely simpler, after the burr's finally been formed and recognized as such.

Insofar as 'wasting metal' goes, that will be minimized greatly, as soon as one learns to look for and recognize the early signs of the burr's formation. That's the visual cue to stop grinding, and change the focus to removing the burr and refining the new edge. More metal gets wasted by those continuing to grind away at an edge, not even realizing they've already created and scrubbed off the burr, possibly multiple times, all the while wondering why the blade doesn't seem to be getting any sharper.
 
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Buck_110 said:
Raising a burr has nothing to do with sharpness.
If the edge isn't chipped or deformed, raising a burr only wastes metal.
A few leading edge strokes are all that's needed the vast majority of the time.
Click to expand...


Most people don't ask "did you form a burr?" because forming a burr is crucial to a sharp edge, they ask so that they know if you apexed the edge or not. The only way we can tell if one properly apexed the edge (without seeing the knife) is if the sharpener is sure they formed a burr. Make sense?
 
Guys, he said he started with a sharp, albeit course, edge from the factory. It was not butterknife dull. If he failed to apex the edge, then he would not have altered the very edge produced from the factory. It should perform the same as before, he will have just worked down the shoulders of the edge.

However, he says he made it duller. So I think maybe he did create a burr, but did not remove it, or he rounded the edge on a strop.

Still, if the edge was rounded he will need to go and apex the edge again, and of course I agree that it is crucial to sharpen to the apex.

ICCW: is there any way you can give us more details on how this was sharpened, and how well does your current edge perform on newsprint? What grits and angle settings are you using on the Aligner/Sharpmaker? Did it get sharper at any point in the sharpening process and then got dull after another step? You are probably very close to getting a great edge, we can help you over the hurdle if you give us enough info.
 
ICCW said:
I'm having problems in my quest for the sharpest possible blade. I take a coarsely sharpened factory edge, sharpen it using a DMT aligner system or even the Spyderco Sharpmaker. I sharpen the blade from coarse to fine, then strop the edge until it literally shines. Once I'm done, however, the shiny, sharp, razor-like edge just isn't as sharp as an edge created with a coarse stone or even the factory edge.

Am I doing something wrong? Any help would be greatly appreciated.
Click to expand...

Before I (or anyone else) get carried away trying to presume what the problem is, perhaps a little more information is needed in regard to how you are gauging and defining sharp.

Guys, he is saying that his final edge is not as sharp as what he gets off the coarse stone...perhaps his problem lies in his expectations of a polished edge vs. a coarse edge?
 
Robs92XJ said:
Guys, he said he started with a sharp, albeit course, edge from the factory. It was not butterknife dull. If he failed to apex the edge, then he would not have altered the very edge produced from the factory. It should perform the same as before, he will have just worked down the shoulders of the edge.

However, he says he made it duller. So I think maybe he did create a burr, but did not remove it, or he rounded the edge on a strop.

Still, if the edge was rounded he will need to go and apex the edge again, and of course I agree that it is crucial to sharpen to the apex.

ICCW: is there any way you can give us more details on how this was sharpened, and how well does your current edge perform on newsprint? What grits and angle settings are you using on the Aligner/Sharpmaker? Did it get sharper at any point in the sharpening process and then got dull after another step? You are probably very close to getting a great edge, we can help you over the hurdle if you give us enough info.
Click to expand...

^This. :thumbup:
Lots of details missing in the OP, so finding the answers to the bolded questions above would go a long ways towards figuring this out.
 
Wow, my sincere thanks to all of you for your posts. I'll try to answer your questions. All of the knives are either Kershaw or Spyderco. I sharpen with either the Sharpmaker or DMT system at about 30 degrees, then strop with a wood-backed strop using the Veritas green compound. During sharpening and stropping, I alternate each side of the blade so I don't think I'm raising a burr.

After reading your posts, I suspect the problem may happen during stropping, because I've been using heavy pressure on the blade (it never occurred to me that I could raise a burr during stropping). The final edge is sharp; it will cut paper or shave hair, but it doesn't seem as sharp as it was before stropping. Unit may be right that I am expecting the edge to retain the qualities of a toothier sharpness. In any case, all of you have given me lots of ideas to test out. Thanks to all of your for your posts and expertise.
 
There's your problem, then!

If you use more that feather-light pressure while you're stropping, you will get your media (in this case, leather coated with an abrasive) rolling up around the edge... and rounding it over!

Really, really light pressure on that strop. :)
 
CrimsonTideShooter said:
Most people don't ask "did you form a burr?" because forming a burr is crucial to a sharp edge...
Click to expand...

Forming a burr by no means guarantees a sharp knife. Leading edge strokes will sharpen without forming a burr.

CrimsonTideShooter said:
The only way we can tell if one properly apexed the edge (without seeing the knife) is if the sharpener is sure they formed a burr. Make sense?
Click to expand...

Impossible! Even if a burr is formed, the actual sharpness of the finished edge does not rely on burr formation.
 
Buck_110 said:
Forming a burr by no means guarantees a sharp knife. Leading edge strokes will sharpen without forming a burr.



Impossible! Even if a burr is formed, the actual sharpness of the finished edge does not rely on burr formation.
Click to expand...


You quite obviously didn't understand my post, go back and read it carefully, then read it again in the proper context.

I am not arguing that burr formation is necessary for a sharp edge...... I am explaining why the question is asked so often in this forum. In no way do I think burr formation is necessary for a sharp edge. Nice try though.


Quote mining like you did makes what I said sound totally different than when it is in proper context. If you really thought I was trying to say that burr formation is crucial to a sharp edge then you have poor reading comprehension skills.
 
Sounds to me like you rounded the edge stropping.
 
ICCW said:
Wow, my sincere thanks to all of you for your posts. I'll try to answer your questions. All of the knives are either Kershaw or Spyderco. I sharpen with either the Sharpmaker or DMT system at about 30 degrees, then strop with a wood-backed strop using the Veritas green compound. During sharpening and stropping, I alternate each side of the blade so I don't think I'm raising a burr.

After reading your posts, I suspect the problem may happen during stropping, because I've been using heavy pressure on the blade (it never occurred to me that I could raise a burr during stropping). The final edge is sharp; it will cut paper or shave hair, but it doesn't seem as sharp as it was before stropping. Unit may be right that I am expecting the edge to retain the qualities of a toothier sharpness. In any case, all of you have given me lots of ideas to test out. Thanks to all of your for your posts and expertise.
Click to expand...

Yep light pressure like the other guys said, and really pay attention to the angle
 
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