Wire edges?

S

SarcoBlaster

Joined
Jul 1, 2002
Messages
602
How can I tell whether I have a wire edge on my knife or not?

I touched up my AR's edge after bringing it home and now it's hair popping sharp. I made 2 rather large cuts down a cardboard box and it was still just as sharp. Thinking that wouldn't get rid of the wire edge (that is, assuming there was one to begin with), I cut into a piece of polycarbonate and it's still just as sharp. Does this sound like it's alright? I looked at the edge under a magnifying glass and didn't notice anything weird. Also, I used the back of a legal pad and stropped for a little while and the [good] results were the same. Thanks in advance for any help you guys can give.
 
Usually you can feel a wire edge by sort of stropping your finger tips over the side of the edge. One side will feel rougher than the other. Sometimes a sharp wire edge will shave differently when you shave in different directions. I sounds like you don't have a wire edge.

Wire edges tend to develop with extensive sharpening. A little bit of material is getting bent over instead of cut off as you hone. It is a somewhat cumulative effect and you get a longer burr if you have honed away more material. Sometimes it is easier to go through a standard burr-removal step when you are sharpening rather than try and detect the beginnings of a wire edge. I always do a removal step. After honing to what seems like a uniform sharp edge I tip my blade up to a 40 degree angle or so. I lightly hone edge-forwards on alternate sides for about 5 strokes per side. Then I go back and hone about 5 strokes per side at my basic 15 degrees per side. I finish with about 5 strokes per side lightly at 20 degrees. If there was any burr to start with it is gone when I'm done.
 
Cool, I guess the edge is fine then. Both sides feel pretty much the same when I run my fingers over and it shaves very easily both ways on my forearm (down towards my hand and up towards my elbow).

Thanks again for the help!:)
 
Here´s something I do:

Draw the knife gently spine first against something hard, like steeling backwards on a smooth steel, at your sharpening angle or a bit higher, the burr will bend a little and you may feel that it seems sharp on one side and dull on the other, do the other side, and the sharp/dull sides change.

Get rid of the burr by stropping or as Jeff recommends, and this bending/changing sharp sides thing won´t happen.
 
The most useful piece of sharpening equipment I've purchased over the last several years (and I've purchased a lot), was a $10 stropping paddle from Highland Hardware (they're here in Atl, but they have a great website). It has a rough side and comes with a rouge for polishing a sharp edge, and also a smooth leather side for that final touch.
It might not remove a wire edge, (follow Jeff's instructions for that) but it'll polish the edge in minutes to razor sharpness.
 
What's a Wire Edge.

I thought it was what we call a feather edge - when a film of metal sits on the edge and waves from side to side. What you seem to be talking about is a burred edge. The best way to tell is an educated thumb (or 2 really) if the edge doesn't seem right with both thumbs you have a burred edge. By the way the best way to revove a feathered edge is to run it across a rolled up newspaper.
 
I can feel a wire edge with my thumb or finger (meat), often with a finger nail.

Once I learned to detect with a finger, I then was able, through practice, to see it by naked eye, in the form of the way the reflection comes off the knife's edge.
 
Rob is onto the technique I use.

This is what I have developed over time:

Hold the knife horizontally, with the edge away from you, and raise it up in front of your face so that you are looking down on the top side of the blade at about a 45 degree angle. Keep it about as close as you can still focus on the edge.

Using a BLUE L.E.D. flashlight -- I use a Photon Microlight II --shine light onto the edge from up near the level of your eyes, down at that same 45 degree angle to the side of the blade.

If there is no "burr" or "wire" edge, the light will simply reflect off the blade away from you. Any burr that is present on that side of the blade will "catch" some light and throw it back to you, since the way the burr is bent up it will be presenting a face to the light. This will appear as a very thin glow of blue at the very edge of the bevel.

This has been working for me for some time now, and I am always able to detect burrs when sharpening, without having to rely on finger sensitivity, which can vary depending on whether your hands and the climate are dry or moist. I can find and remove burrs on knives that I am sure would feel burr-free to most people's fingers.

---Jeffrey
 
I use my fingernails to feel for the burr, that way I can feel it even if my hands are sweaty. That sounds like a really good idea with the light though peacefuljeffrey, I'll have to give it a try.
 
You must log in or register to reply here.
Back
Top