How to remove a burr?

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ryts100

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Feb 19, 2009
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After I sharpen my Benchmade Griptilian, whenever I look at the edge in the light, the very edge is shiny, and I'm assuming it's a burr. Does anyone know how to remove it, or prevent it in the first place? Currently I have 2 DMT Diafolds; EC and C, and F and EF, as well as a leather strop with 6 micron DMT paste, and a leather strop with 1 micron diamond spray. After the EF Diafold, I don't see any burr, but after the 6 micron strop there is, and it's still there after the 1 micron strop. I don't think I'm using too much pressure either.
 
If its a burr, you should be able to catch your fingernail on it as you slide your nail across the cutting edge (from the direction of the spine). It will be on the side of the edge opposite from the side you just sharpened - of that make sense.
 
powernoodle said:
If its a burr, you should be able to catch your fingernail on it as you slide your nail across the cutting edge (from the direction of the spine).
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I know about that test, and I use it when I'm reprofiling, but for this burr it doesn't work, my fingernail just slides off. However, when I drag the knife across my fingernail in a stropping motion, it scrapes some of the enamel off. Since I'm dragging the spine towards me, I'm assuming this means there's a burr?
 
Your not using the strop long enough.
 
ryts100 said:
Since it seems like the strop is forming the burr, wouldn't that be counterproductive?
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This seems odd to me too. I don't think I've ever heard of a strop actually forming a burr (unless maybe it was a powered strop on a grinder/buffer). I'm betting it was already there to begin with (after sharpening on the stone), and the stropping has bent/curled it to one side, making it more noticeable.

As far as removing it goes, you might try cutting into a piece of wood (as if whittling) or into a piece of thick, stiff leather. Draw the blade through the wood/leather, along the full length of the cutting edge. Sometimes that helps to break the burr off. Then return to stropping & check your edge again.
 
Obsessed with Edges said:
This seems odd to me too. I don't think I've ever heard of a strop actually forming a burr (unless maybe it was a powered strop on a grinder/buffer). I'm betting it was already there to begin with (after sharpening on the stone), and the stropping has bent/curled it to one side, making it more noticeable.

As far as removing it goes, you might try cutting into a piece of wood (as if whittling) or into a piece of thick, stiff leather. Draw the blade through the wood/leather, along the full length of the cutting edge. Sometimes that helps to break the burr off. Then return to stropping & check your edge again.
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After the EF Diafold, the whole edge is satin finished looking, and when I hold it up to the light, no part of the edge is shiny. After the 6 micron strop, the entire edge(secondary bevel?) is shiner, and the very very edge is really shiny. I don't have any thick leather or wood on hand right now, unless a paint stir stick works?
 
A abrasive at almost any grit will form a burr and 6 micron is still fairly abrasive so its no exception. When the 6 micron compound is being used after the EF stone it take a minute to reduce the scratch pattern, the finished scratch pattern from the 6 micron should be slightly mirrored with a haze like scratch pattern. If stropped correctly the edge should be hair splitting or real close and feel still a bit toothy but polished.
 
knifenut1013 said:
A abrasive at almost any grit will form a burr and 6 micron is still fairly abrasive so its no exception. When the 6 micron compound is being used after the EF stone it take a minute to reduce the scratch pattern, the finished scratch pattern from the 6 micron should be slightly mirrored with a haze like scratch pattern. If stropped correctly the edge should be hair splitting or real close and feel still a bit toothy but polished.
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That pretty much describes the edge I have after I strop. When you say hair splitting, do you mean dropping a hair on the edge and letting gravity cut it? And yes, it does feel a little toothy.
 
ryts100 said:
After the EF Diafold, the whole edge is satin finished looking, and when I hold it up to the light, no part of the edge is shiny. After the 6 micron strop, the entire edge(secondary bevel?) is shiner, and the very very edge is really shiny. I don't have any thick leather or wood on hand right now, unless a paint stir stick works?
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The paint stick is relatively soft wood, but there's a decent chance it'll still do. If anything, make a few more cuts into it. Don't be afraid to cut DEEP into the wood, then draw the cutting edge through it, from heel to tip. Then strop again & check your edge.

The 'shine' on your edge may not necessarily be a burr in itself. Might just be a microbevel that's been polished by the stropping. If you're not able to feel a burr with your fingernail, another way to test for it's presence is to slice a piece of light paper (such as a telephone book page). Make 3 or 4 cuts, along the full length of the cutting edge. If the edge catches or snags midway through the cut, that's a good sign you have a burr. If, on the other hand, you can repeatedly slice cleanly & smoothly from heel to tip without snagging in the paper, chances are good the burr's gone.

Sometimes I've been able to see a burr 'scrape' little bits of leather from a strop while stropping. If the strop has a layer of colored compound on it, it's all the more visible. When stropping the side with the burr, the burr will 'collect' the compound, much as if you'd scratched the strop with your fingernails and collected compound underneath the nails.
 
Obsessed with Edges said:
The paint stick is relatively soft wood, but there's a decent chance it'll still do. If anything, make a few more cuts into it. Don't be afraid to cut DEEP into the wood, then draw the cutting edge through it, from heel to tip. Then strop again & check your edge.

The 'shine' on your edge may not necessarily be a burr in itself. Might just be a microbevel that's been polished by the stropping. If you're not able to feel a burr with your fingernail, another way to test for it's presence is to slice a piece of light paper (such as a telephone book page). Make 3 or 4 cuts, along the full length of the cutting edge. If the edge catches or snags midway through the cut, that's a good sign you have a burr. If, on the other hand, you can repeatedly slice cleanly & smoothly from heel to tip without snagging in the paper, chances are good the burr's gone.

Sometimes I've been able to see a burr 'scrape' little bits of leather from a strop while stropping. If the strop has a layer of colored compound on it, it's all the more visible. When stropping the side with the burr, the burr will 'collect' the compound, much as if you'd scratched the strop with your fingernails and collected compound underneath the nails.
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I'm pretty sure the shine is a burr. I made about 20 or so cuts through binder paper just now, and it went through just fine the first 10 cuts or so, then started snagging at the start of a push cut. Slice cuts are fine though. Assuming this is a burr, it's not large enough to scrape the surface of my strop.
 
Here are a few pics I managed to take of the edge. Sorry the quality is bad, Im using my laptop webcam with a loupe taped to it :o.
image201006200003.jpg

image201006200002.jpg

image201006200004.jpg
 
ryts100 said:
I'm pretty sure the shine is a burr. I made about 20 or so cuts through binder paper just now, and it went through just fine the first 10 cuts or so, then started snagging at the start of a push cut. Slice cuts are fine though. Assuming this is a burr, it's not large enough to scrape the surface of my strop.
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Another possibility, if the burr is extremely stubborn, is to 'strop' the edge lightly on a ceramic stone, or make a couple of gentle 'slice cuts' (as in sharpening) into the ceramic stone, to break the burr off. I occasionally use my Spyderco 'Double Stuff' stone this way, when the burr won't come off by other means.
 
Obsessed with Edges said:
Another possibility, if the burr is extremely stubborn, is to 'strop' the edge lightly on a ceramic stone, or make a couple of gentle 'slice cuts' (as in sharpening) into the ceramic stone, to break the burr off. I occasionally use my Spyderco 'Double Stuff' stone this way, when the burr won't come off by other means.
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I'll try the paint stick then strop first, and if that doesn't work I'll try the ceramic stick. Your comment brought up another question though. I sharpen and strop with the same motion, spine leading, heel to tip. Should I be pushing the edge into the stone, heel to tip? Obviously not on the strop though.
ETA: I made several cuts threw the paint stick, and drew the edge through it, but the burr is still there. I'll strop it and try the ceramic stick.
 
ryts100 said:
I'll try the paint stick then strop first, and if that doesn't work I'll try the ceramic stick. Your comment brought up another question though. I sharpen and strop with the same motion, spine leading, heel to tip. Should I be pushing the edge into the stone, heel to tip? Obviously not on the strop though.
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Yes, that's what I was referring to. Use an edge leading stroke (into the stone) on the ceramic. If the burr is there, that would hopefully fold the burr underneath, against the stone, and break it off. And, definitely, you don't want to do that on the leather. ;)
 
Obsessed with Edges said:
Yes, that's what I was referring to. Use an edge leading stroke (into the stone) on the ceramic. If the burr is there, that would hopefully fold the burr underneath, against the stone, and break it off. And, definitely, you don't want to do that on the leather. ;)
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I stropped it with the 6 and 1 micron strops, then made 4 passes per side edge-leading on a white Lansky ceramic rod. The burr is still there :mad:.
ETA: I'll get the EF Diafold out, post pics of the edge after I'm done with it, and the same with the 6 and 1 micron strops.
 
I still think you need to strop more and ease up on the pressure. Using less pressure will reduce the formation of the burr and increase the level of polish.

I check for burrs by stropping the edge on my thumb nail, the size of the burr can be felt this way and it will better help you to decide on your next step. In some cases you might not be able to completely rid the edge of a burr at 6 micron, or you might actually need to go back to your EF stone and refine the edge slightly more.

Factors like, how new are your stones? how much pressure are you using with them? how long are you stropping and what steel? What happens when you go to a finer strop?

To me it seems as though you are doing good but maybe expecting results to be faster then your getting them?
 
I'm still wondering if this isn't just a tiny microbevel (that's what it looks like in your pics). I think a burr would've been removed after all this, or at least changed. You were able to make multiple (10) slice cuts into the paper. If a significant burr were there, I doubt you would've gotten that far (in my experience, a burr would usually move/flop to one side or the other after the 1st/2nd/3rd cut, after which the slicing performance would noticeably change).
 
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