Is a bur actually needed?

[s4mpson]

I have read the whole thread and understand the pros and cons of burr based and non burr based sharpening. Picking a side seems a bit silly. I was simply answering the title question.

Forming a burr is not necessary, but if one finds it easier to sharpen by forming one, a sharp knife is better than a dull one. For steels that form a tenacious burr, burr based sharpening makes it more difficult, and knowing how to sharpen without forming one permits use of those steels without special/involved burr removal procedures.

Fair enough my man, carry on.

 

[bucketstove]

Hi,

Again it depends on the thickness, as explained by the diagram. A 0.1 micron thick foil will not break off by stropping it on clean leather, but it will prevent the blade from shaving.(not sure if you know those are my "pictures").

yes I was aware I linked your pictures nice work thanks

I make sure all my burrs are about 0.4 micron

I can't break aluminum food wrap by bending it back and forth, can you?

FWIW,
yes I can't and yes I can it depends how its done, and it can take more than a hundred bends
but unlike a knife
the sheet is a sheet , its uniformly thin
where on a knife the burr is attached to a much thicker piece of metal it can be bent against
and unlike steel
aluminum is more maleable/ductile
and I've never been able to shave with aluminum foil

 

[bgentry]

I'm lost on the point with all of this theory and analogies to different mediums that are not blades. What's the argument here? That somehow there's an edge retention difference between a burr sharpened edge and one that's sharpened without a burr? Or a difference in sharpness?

Can anyone point to actual evidence of some sort of difference? I personally don't think it matters, but I haven't really done much testing on this myself.

Brian.

 

[fjblair]

I'm lost on the point with all of this theory and analogies to different mediums that are not blades. What's the argument here? That somehow there's an edge retention difference between a burr sharpened edge and one that's sharpened without a burr? Or a difference in sharpness?

Can anyone point to actual evidence of some sort of difference? I personally don't think it matters, but I haven't really done much testing on this myself.

Brian.

The knowledge expressed here is deep, but sometimes too pedantic for it's own good. We are talking about sharpening knives.

 

[HeavyHanded]

I'm lost on the point with all of this theory and analogies to different mediums that are not blades. What's the argument here? That somehow there's an edge retention difference between a burr sharpened edge and one that's sharpened without a burr? Or a difference in sharpness?

Can anyone point to actual evidence of some sort of difference? I personally don't think it matters, but I haven't really done much testing on this myself.

Brian.

Amen Brother, I haven't noticed any difference. What's next, an edge lapped with lose grit vs one ground against a fixed abrasive?

 

[HeavyHanded]

What's next, an edge lapped with lose grit vs one ground against a fixed abrasive?

Actually a trick question-loose grit in a slurry makes a sharper, cleaner edge. Is how microtome blades are finished.

 

[JD Spydo]

Cliff is right--you don't need nor actually want a burr. It's just an easy way to tell that you've fully apexed the edge on that side, but a keen eye looking at your scratch pattern can tell you the same thing without having to create a burr.

I couldn't agree more! Even the freehand sharpening I do with my benchstones I rarely ever encounter a burr. Unless I have a really beat up blade that requires an extensive re-profiling which I don't encounter very often. I rarely let one of my blades or edged tools ever get that bad unless I had a very rough job of some sort.

Now occasionally I'll encounter a "burr" using my diamond stones sometimes but most of the time I just don't. Now I do think that the "burr" could be a good indicator for a beginner in the skill of sharpening. But for someone who is knowledgeable about the different blade steels then I don't see any necessity in it at all. I used to rely on it at one time but I haven't in quite a while now.