Ways to test for a burr?

[Jason B.]

That shiny "white line" is the burr. That's what it looks like under bright light. When inspecting the edge you must turn the knife (twisting from the handle) and watch for any reflections or bumps at the apex of the edge. If the edge has no burr it will look almost dark and have a distinct bite into your finger. Grit really doesn't matter but as the edge becomes finer so will the feel of bite in your finger. The "bite" I refer to is when you lay your thumb on the edge and lightly press and pull your finger to the side. (Obviously your feeling a sharp object here so your touch should be feather light)

As soon as the finger is moved the edge should bite into the skin, just remember as the grit of finish increases the bite becomes more instant and upon contact. If the edge does not bite then you still have more work to do.

Did you use push or draw strokes for the micro?

Try putting the Chromium oxide on a piece of hardwood or MDF and doing the micro with that after the 1k. A ceramic rod or a UF SM rod would be much better though.

 

[KennyB]

That shiny "white line" is the burr. That's what it looks like under bright light. When inspecting the edge you must turn the knife (twisting from the handle) and watch for any reflections or bumps at the apex of the edge. If the edge has no burr it will look almost dark and have a distinct bite into your finger. Grit really doesn't matter but as the edge becomes finer so will the feel of bite in your finger. The "bite" I refer to is when you lay your thumb on the edge and lightly press and pull your finger to the side. (Obviously your feeling a sharp object here so your touch should be feather light)

As soon as the finger is moved the edge should bite into the skin, just remember as the grit of finish increases the bite becomes more instant and upon contact. If the edge does not bite then you still have more work to do.

Did you use push or draw strokes for the micro?

Try putting the Chromium oxide on a piece of hardwood or MDF and doing the micro with that after the 1k. A ceramic rod or a UF SM rod would be much better though.

I don't know, no matter what i do I can't see the same little white line under natural light, only with the camera flash. Had my desklamp literally right on top of it and a 30x loupe as well. Is it possible the camera is distorting it or somethign? Not a very good camera...

At this point I think I'm pretty much in the dark in whether I have a burr. Can't feel one in any normal way, the edge definitely bites as you say, and as I said after alternating strokes it shaves hair equally well on both sides. I'm thinking that maybe the edge in general is still just in lousy shape from the leather since that dent is still in there pretty good.

Oh, and I did push-strokes.

I didn't think CrO on MDF would be abrasive enough to do a micro-bevel, but my main concern is that if I'm having trouble feeling a burr now if I would be able to tell if I raised one on CrO.

Edit:

Oh, yeah, and I just checked it under 30x and the edge is pretty dark, can barely see it. Only part of it that comes in really well is the dent that's still left from leather.

 

[Jason B.]

The dent from leather is something I just can't grasp in any way. Considering you used push strokes to microbevel on a waterstone I'd say you hit the edge in that spot.

You wouldn't have to worry about raising a burr with a MDF strop, it would just polish in a sharp edge.

If its sharp and you can't tell in any way that you have a burr then IDK, your probably good.

 

[KennyB]

The dent from leather is something I just can't grasp in any way. Considering you used push strokes to microbevel on a waterstone I'd say you hit the edge in that spot.

You wouldn't have to worry about raising a burr with a MDF strop, it would just polish in a sharp edge.

If its sharp and you can't tell in any way that you have a burr then IDK, your probably good.

Nah, beacuse that dent is the reason I took it to the stone in the first place. It's actually much smaller now than it was right after cutting it too. Left the dent and rolled the edge around it, so maybe that's what those rough spots on the camera are. I don't know, I think I'm going to take it to my coarse stone and see if I can get it all out this time around. I keep raising a burr on the 220, and then it looks like the dent is gone, but after I finish it up it's still there.

But, yeah, I was filleting a little piece out of an old belt, so either it was the leather or the black crud that's on the outside of it. Maybe an impurity in the belt or something? I just figured that I had the edge ground a little too thin.

Either way, this microbevel I added fixed it up. Cut a similar piece out of the same belt last night and it didn't do squat to the edge

The dent is really deep though. I can't get picture of it better than that, but when I look at where the edge is at and where the deepest point of the dent is, it is fairly visible even a foot away from my face. One of the reasons I thought it was a chip at first was because of how large it was originally; if I had to estimate I'd say it was .005-.010" at the deepest. So I think maybe if anything I just need to grind that dent out completely so I make sure the edge I put the microbevel on is pristine to start out with.

 

[Obsessed with Edges]

Kenny,

To me, that dent on the edge looks a lot like the flat-spotting that results from the edge colliding with the backspring/spacer. Yours appears to be in the central portion of the edge? If so, it wouldn't surprise me if the edge sometimes bumps into the 'swell' in the backspring, where the spring's anchor/rocker pin is. I see this a LOT on traditional folders. Usually, if you look inside the handle at the backspring, you'll also see a tell-tale nick in the backspring. As small as they look, they do take quite a bit to smooth out. I usually don't progress beyond 400/600 grit until any sign of the dent is gone. It's very hard to remove it with anything much finer than that.

If this isn't applicable to your situation, please disregard. But, when I saw the pic of the dent, it looked all-too-familiar to me.

 

[KennyB]

Kenny,

To me, that dent on the edge looks a lot like the flat-spotting that results from the edge colliding with the backspring/spacer. Yours appears to be in the central portion of the edge? If so, it wouldn't surprise me if the edge sometimes bumps into the 'swell' in the backspring, where the spring's anchor/rocker pin is. I see this a LOT on traditional folders. Usually, if you look inside the handle at the backspring, you'll also see a tell-tale nick in the backspring. As small as they look, they do take quite a bit to smooth out. I usually don't progress beyond 400/600 grit until any sign of the dent is gone. It's very hard to remove it with anything much finer than that.

If this isn't applicable to your situation, please disregard. But, when I saw the pic of the dent, it looked all-too-familiar to me.

Yeah, that thought had occured to me as well too, but I've already checked this knife for that particular problem so many times I don't think it could be it. Plus, I remember taking a cut off the leather and obsessively checking the edge ( I'm one of those guys that can't even cut cheese without seeing what it did to the edge ) and being shocked when I saw the dent, and even more shocked when I felt the rolled edge.

My guess was that the edge was just too thin. It was a 30* or less inclusive bevel and the width behind the edge shoulder was only .020". The microbevel certainly seems to have helped.

 

[Obsessed with Edges]

Yeah, that thought had occured to me as well too, but I've already checked this knife for that particular problem so many times I don't think it could be it. Plus, I remember taking a cut off the leather and obsessively checking the edge ( I'm one of those guys that can't even cut cheese without seeing what it did to the edge ) and being shocked when I saw the dent, and even more shocked when I felt the rolled edge.

My guess was that the edge was just too thin. It was a 30* or less inclusive bevel and the width behind the edge shoulder was only .020". The microbevel certainly seems to have helped.

You too, huh?

OK. I've been sharpening a Queen Country Cousin that had just such a dent in the edge (from smacking into the backspring), straight out of the box. That's why I brought it up.

Glad to see that things seem to be working out with your edge. :thumbup:

Best regards.