Is it necessary to raise a burr?

M

me2

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Oct 11, 2003
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I say no. I tried a new-is-old sharpening method this weekend and it worked like a charm. When I first started sharpening, I did this, but didn't know enough to know why or how it worked. I sharpened until the edge stopped reflecting light, then just polished the edge until it was as sharp as I wanted. I did this for years and got edges that would shave my face. I got this method from David Boye's book Step by Step Knifemaking.

Then I read about burring and removing and pretty much switched to that. Then a member on some other forums I frequent posted a youtube video and recommended not raising a burr, and only going until the edge stopped reflecting light. It still works. I got an edge that would whittle beard hair off my coarsest stone, 220 King, and refining it on my King 1000 stone let me treetop arm hair and whittle hair off my head. This was all done free hand and took about 15 minutes. The knife used was a RADA Cutlery Santoku that had been reground. The time could have been less, but there was some damage to the edge from sloppy regrinding that had to be removed.

I do think a slight burr was raised, but it was by accident, and I couldn't for sure detect it with my normal methods of stropping on cloth and looking for fuzz, or stropping on the back of my head and feeling for the burr pulling my hair. Both these are pretty sensitive methods. I did include one light deburring pass on each side of the blade, just in case, done at an elevated angle.
 
I think raising a burr is just the more fool proof way of making sure you're down to the edge. I reprofile on a DMT blue/red stone. I get as close as I can to a burr with the blue (i.e. not fully to the edge but close), then switch to the red. The red puts a better finish on it but is still coarse enough to get it down to the edge without taking awhile. That seems to work well.
 
A burr could have been raised and sharpened off and you just didn't know it. I don't think a burr has to be felt. Merely, seen and worked off is good enough. DM
 
Burrs that are detectable by my normal 2 methods are not large enough for me to see. One of the most frustrating things about sharpening is chasing a tenacious burr. Not forming one in the first place eliminates that problem.
 
How are you sure to avoid a wire edge? The steel debris has to go somewhere, I'm afraid.
 
Thanks for posting about your technique. Do you sharpen with an edge trailing or edge leading technique?

I don't see how edge trailing sharpening can avoid a burr. Like Benuser posted, the metal removed has to go somewhere and as it hangs over the apex, it forms the burr.

If you are sharpening edge leading, you are still removing metal.

Either way, to get a knife sharp, metal is removed. It's just when a burr is formed, it's a good indicator of when to stop removing metal.

Or I may be totally off base. I find this interesting & would like to hear from the many BF members who are more knowledgeable on this subject than me.

Allen
 
aread said:
Either way, to get a knife sharp, metal is removed. It's just when a burr is formed, it's a good indicator of when to stop removing metal.

Allen
Click to expand...

Thats what I use the burr for, a visual indicator of FAR ENOUGH.
 
As I see things, grinding till the edge stops reflecting light means you are grinding to the apex. Unless you have the ability to stop with uber precision, you are most likely creating a burr anyway. When I'm grinding I look for both, no light from the apex on the grind side, and I need to see the hint at least of a burr forming on the opposite. It is possible in my experience to grind a fresh apex using waterstones without raising an appreciable burr. There is frequently still one present, but it gets disguised by the lapping action of any loose grit on the stone. With careful technique tho it can be avoided entirely. I find it takes longer to carefully grind and observe to this level than it takes to quickly whip up a burr and remove it.
 
HeavyHanded said:
As I see things, grinding till the edge stops reflecting light means you are grinding to the apex. Unless you have the ability to stop with uber precision
Click to expand...

I've felt the same way- why create a burr and then worry about how to get rid of it, just stop before it occurs. Another thing that I've worried about is that your entire edge might not be the same amount of dull. So as you sharpen are you starting to form a burr at one spot before another spot is sharp? Another thing I've wondered about- reading about people that do trailing edge sharpening with paper wheels and strops, maybe you can stop somewhat before a burr is to be formed and then switch to a trailing edge system to finish the edge.
 
I'm also inclined to believe that if you are actually apexing the edge, you are in fact creating a burr, however small it may be. It would take extreme precision to avoid it, if the edge is fully apexed. Think CNC machine-level precision with very close monitoring and feedback; precision like this would be impossible by human hand alone. So, achieving 'true' apex more than likely necessitates detecting the burr first. Otherwise, you've probably stopped somewhat short (or, as mentioned, created and scrubbed the burr away without being aware of it). With more experience, it'll become easier to detect the burr at a much earlier point, before it gets too big.

I've stopped worrying about burrs, beyond making sure I can detect them (and there are many ways to do that, beyond being able to actually see it, or feel it with a fingernail). Get familiar with various means of removing them & refining the edge, and the presence of the burr on the apex becomes a minor point, and much less intimidating. I don't like stopping before knowing the burr is there, because in almost every instance I've done it, I've eventually figured out I could've taken the edge even finer. Stopping short of detecting a burr has always resulted (for me) in edges that aren't as sharp as they could be. This is not to say that stopping just shy of making a burr will result in an unusable edge; it won't. For 99% of typical usage, it'll usually be fine. It's just that there's still some room to make it better. :)
 
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Dont confuse unneccesary with unavoidable. There is also need for distinction between macro and micro burrs. If the magnification is high enough, microburrs are nearly always present, no matter how carefully we deburr. My comments are directed primarily at the large burrs used to detect when sharpening can procede to the next step. There is nothing that says one cant just alternate sides one pass at a time from coarse to as fine as needed.
 
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