Is getting a burr that important?

AFAustin said:
Let me ask a related question. I will often read advice to sharpen one side till a burr is formed, then switch to the other side and repeat the process. But, at least in the case where a blade is dull and a fair amount of steel needs to removed to initially form a burr, aren't you creating an uneven bevel by following this advice? That is, while you would be doing many passes on the first side to get a burr, once that's done and you switch sides, it won't take much to re-form the burr (or flip it over). So, isn't the result an uneven bevel?

On a dull knife, wouldn't it make more sense to do a moderate number of passes on one side, then switch to the other side (even though a burr hasn't formed yet) and do a similar number of passes, and then switch back, and so on till the burr is formed, thus keeping the amount of steel removed from each side about the same?

Andrew
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I think that's why some experienced knife sharpeners examine the knife first and one of the things they check is whether the bevel is uneven. If the bevel is uneven, then they would work on the appropriate side first. If the bevel was already uneven in the first place, your method of switching sides after similar number of passes would only maintain the unevenness of the bevel.

If the knife was a "working" knife, I don't believe the biggest concern is the unevenness but rather two things: 1) keeping it sharp and 2) extending the tool life. Given that, if the bevel was uneven, the side to sharpen first would be the one with the shorter bevel. Then the goal would be not to remove enough material so that the bevel would be even but, rather, to fully apex the edge.

Because the whole length of the bevel won't be shaved down at the same time to the point when that side forms 1/2 of an apexed edge and because it is quite difficult to stop the sharpening stroke at exactly the point when that side forms 1/2 of the apex and is just short of one molecule away from forming a burr, it is humanly impossible to not create a burr and have the that side form 1/2 of an apexed edge. The goal then is to remove enough material for that side to be 1/2 of the apexed edge and one evidence of this is that a burr is formed along the edge. Some people recommend to make a large burr to ensure that the bevel is indeed formed to be 1/2 of an apexed edge.

People use stropping as a final step to remove the burrs to "perfect" the edge. This tends to indicate that burrs do occur even if that isn't the main goal that people shoot for.

To answer your question: on a dull knife, if the bevels on either side were even, you would just work either one of the sides until you've removed the minimum material and have 1/2 of the apex. Then you'd work the other side. When you're done, the edge is sharp, the bevels remain even, and only the minimum material have been removed thus prolonging the tool life. If the bevels were uneven, you'd work on the short side first and do as above. The bevels may still not be even after the knife has been sharpened, but continued working the short side first on subsequent sharpenings will address the issue.
 
While technically possible to sharpen an edge without creating a detectable burr, it is by far the most reliable method - most non-burr forming sharpening methods involve relatively thin slurries on powered equipment. For most of us, one the lightest of touch-ups are possible without some form of burr generation (and even then...).

When hand sharpening it is virtually impossible not to do so, might as well embrace it. It does not remove any more steel than failing to decisively cross the apex and one gets the benefit of guaranteeing the new edge. IMHO it also saves a ton of time on QC - easier to raise and remove than to push to the apex trying all the while to avoid creating one. Also, on larger tools how could one possibly have the level of angle control needed to push the entire edge to a new apex without raising a burr, and guarantee doing so, and in a reasonable amount of time.

On heavily worn edges I will go back and forth sides to keep the grinds even, or work whatever side needs it more to make an even grind if it is a consideration.

The ceramic knife analogy is not applicable to sharpening steel tools, steel is ductile and malleable - hence the burr.
 
What I meant in my initial statement was that I don't create any noticeable burr. Cotton swabs don't snag and I cannot feel it with my nail. I alternate stroke for my entire process thus removing any burr the moment it forms. I have gotten hair whittling edges this way using a Wicked Edge. The way I know I have apexed the edge is by using a sharpie to coat the edge, and by running my nail along the edge to detect the difference in "toothyness".

As for AFAustin's question. Yes, if you sharpen only one side till you build a burr, then switch to the other side and do the same you will have an uneven bevel. I myself did this to a few knives when I first got my Wicked Edge.

Hope that makes sense.
 
HeavyHanded said:
While technically possible to sharpen an edge without creating a detectable burr, it is by far the most reliable method - most non-burr forming sharpening methods involve relatively thin slurries on powered equipment. For most of us, one the lightest of touch-ups are possible without some form of burr generation (and even then...).

When hand sharpening it is virtually impossible not to do so, might as well embrace it. It does not remove any more steel than failing to decisively cross the apex and one gets the benefit of guaranteeing the new edge. IMHO it also saves a ton of time on QC - easier to raise and remove than to push to the apex trying all the while to avoid creating one. Also, on larger tools how could one possibly have the level of angle control needed to push the entire edge to a new apex without raising a burr, and guarantee doing so, and in a reasonable amount of time.
On heavily worn edges I will go back and forth sides to keep the grinds even, or work whatever side needs it more to make an even grind if it is a consideration.
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I go this route. It seems to be the best sure fire method. It's sooo small a difference in the amount of metal removed to completely do it that it gives the OCD guys something to worry about. DM
 
the best advice is to do what works for you, if you are happy with a touchup and not going to the burr then so be it. myself ,if I didn't raise a burr I wouldn't have given it my best edge and would not accept it as a sharpened knife just a touched up one. I don't own a knife that is below scary sharp and wont carry one that's not.
 
yepimonfire said:
Just because an edge doesn't reflect light doesn't mean it's fully apexed.
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That's why I personally go mostly off feel. It's hard to explain, but when sharpening I can tell I've apexed the edge just by feeling it. That combined with the other methods I listed have given me consistent effective results.
 
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