Can I have a burr on my knife and still whittle hair?

[KnifeCarsen10]

Hey guys, I was wondering if you guys have ever had a burr and still be able to whittle a feee hanging head hair. I can do it, but not extremely consistent, and sometimes not at the tip or heel of the knife. Any advice or suggestions? Thanks!

 

[cchu518]

Yes....that is until you actually use the knife on something harder and the burr folds over in itself.

 

[SVTFreak]

What's he said. It'll seem very sharp. But lose that edge very quickly.

 

[KnifeCarsen10]

So how exactly can I tell when I have a burr on such fine stones? I feel it but don’t feel anything. How can I tell if I have a burr?

 

[Wowbagger]

So how exactly can I tell when I have a burr on such fine stones? I feel it but don’t feel anything. How can I tell if I have a burr?

Go to this Link > > > and page down to the jeweler's visor.
This helps along with some light over your shoulder or placed any other way that helps you see the bur by reflecting light off it.

There is also a sharpening technique called Apex Sharpening where you never actually raise a bur. Takes experience though. Check out some YouTubes about Apex Sharpening. Let me know if you don't find a good one.

Your very best bet is only sharpen really great steel alloys that are properly heat treated; meaning on the hard side (in the 60s as opposed to in the the 50s rockwell hardness scale).
What are these alloys ? : N690, M4, White Paper steel, HAP-40 and good old ZDP-189 are a few.
These alloys loose the bur quick and cleanly as you refine the edge on finer stones.

If you allow your self to slip down into the pit of cheep stainless or low hardness high production stuff . . . learn to "LIKE" the bur is all I can say because you are going to be living with a lot of it.

Sure even a minuscule; almost imperceptible bur is going to whittle hair and then later fold over when you actually use the knife; or if you are lucky the bur will tear off. Usually a bur will only whittle to one side meaning if you take your trusty jeweler's visor and observe single hairs that are still in your arm you may be able to cut curls off one in one direction but not if you flip the knife over and try it on another hair going in the opposite direction using the other side of the blade edge. That is one way to tell you aren't done refining the edge if the knife whittles hair only on one side.

 

[wootzblade]

We have developed a method to differentiate wire edge from the clean apex - it is detailed in the Quality Control chapter of our Knife Deburring research http://knifegrinders.com.au/Manuals/Knife_Deburring_book.pdf

Even if you do not own a BESS sharpness tester, you can do a simplified test for wire edge by cross push-cutting a stretched fluorocarbon fishing line, and checking under good light or with a loupe if the very edge has got a micro-dent in the point of the cut – wire edge will dent, while the cleanly deburred apex will not. The fluorocarbon fishing line must be 7 LB 0.21 mm or near that.
This simplified method works for mainstream knives, but not for high-end hard-alloy steels.

Because the wire edge is too weak to cut the fishing line, it crushes on it and, as we increase the downward pressure, mushrooms against the line allowing to apply more pressure onto the widening point till the line gets finally severed. In the point of testing, we see a micro-dent in the edge with the mushroomed apex displaced to the dent bottom.
Microscope image follows, but this dent can be seen naked-eye:

 

[HeavyHanded]

Hey guys, I was wondering if you guys have ever had a burr and still be able to whittle a feee hanging head hair. I can do it, but not extremely consistent, and sometimes not at the tip or heel of the knife. Any advice or suggestions? Thanks!

Short answer, yes.

And in my experience it can hold up for a few in use.