Not sure about Burr

A

alwyn

Joined
Aug 7, 2010
Messages
29
Have been sharpening a knife and cannot decide if I've got a burr, or this has just been metal filings. Have tried to drag my nail from spine to tip but still cant be sure.
How do you guys make sure you have a burr?

Alwyn
 
Hang a needle from a thread and let it slide down the side of your blade. If you have a burr it will catch on it. Other things that help are good light and magnification.
 
mongolguy said:
Hang a needle from a thread and let it slide down the side of your blade. If you have a burr it will catch on it. Other things that help are good light and magnification.
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I like that...

Usually I use the edge of my fingernail and run it up the face of the bevel and see if I can feel it catch, but sometimes burrs are too small to catch like that. If you can't find them until they're really big, they'll be that much harder to grind off and to be sure they're not there, so I generally try to stop as soon as i can feel the slightest burr that goes across all the edge.

Another thing someone here taught me ( I believe it was knifenut ) is to slide the bevel face along the surface of your fingernail, if there's a burr on it you can feel it catch. This is more useful to me for another reason ( seeing if there's a stubborn burr still on there that's too hard to see ) but it should help to help you tell when you have one too.

Other thing you can use is some kind of loose cloth or paper towel, and rub that side on it. If there's a burr it should catch fibers, but I don't really like to do this because by the time it does this the burr is usually really big
 
Razorsharp-Travis said:
hold a high power light to the edge, it its shiny (check both sides) right at the edge- its burred :)
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^This.

I find that while I can feel burrs from coarse grit abrasives, I typically won't feel anything from finer abrasives. A good light will show everything from dust to chips, to rolls, blunts, and burrs.
 
i like to use the fingernail method. if it doesn't catch while sliding it down my nail, there is a burr.
 
Noctis3880 said:
^This.

I find that while I can feel burrs from coarse grit abrasives, I typically won't feel anything from finer abrasives. A good light will show everything from dust to chips, to rolls, blunts, and burrs.
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I'm with you on this note, I find anything above 600 grit to me is usually to fine to feel a burr, unless it's really big, so once I get that high in grits I just do a 1-to-1 ratio on both sides
 
you can use a sewing needle with a short length of thread attached to detect a burr. hold the thread close to the eye and hold the needle with the point on the blade just above the edge and slide it down. if there is a burr the needle will catch.
 
With good light and magnification, I can see a burr that is too small to feel. On account of this fact, I remove less material from the blade if I sharpen by inspection, and my knives last longer.
 
tiguy7 said:
With good light and magnification, I can see a burr that is too small to feel. On account of this fact, I remove less material from the blade if I sharpen by inspection, and my knives last longer.
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+1 - me too.
 
The paper towel 'trick' will reveal a lot more, if it's moist/wetted. The wet paper will cling to the edge, and burrs will grab fibers from it, leaving little 'flags' hanging where the burrs are.

Another way I've found burrs, is to slice into the edge of a piece of thin paper (like phone book pages, catalog pages or newsprint). Slice slowly along the full length of the cutting edge, and watch for where the edge snags or grabs the paper; that'll always reveal where the edge needs some more cleaning up or refinement. When you can repeatedly slice cleanly and effortlessly through the paper, using the full length of the cutting edge, that's an excellent indication your edge is ready.
 
IMHO nothing works better than some good overhead lighting and a loupe thats 8x minimum to 15x (6x or less is just too far away for me to see well). I hold the blade straight up and down, edge pointing down, and slowly pivot it back and forth. I can find burrs that are too small to be detected any other way. Since I've gotten access to a fairly high-power microscope, I have yet to find a burr at any level of magnification that wasn't visible to some extent at 15x (surprising really, but so far...). If I really want to get tough, I'll lightly strop the edge on some hardwood at a steep angle a few times and check again - if a burr doesn't "turn up" from that treatment, there isn't one there to see.
 
Use a Q-Tip. The burr will catch on the cotton fibers very easily.
As the blade is finely honed the Q-Tip will not catch and you'll
know it's smooth and sharp.

Bill
 
HeavyHanded said:
...If I really want to get tough, I'll lightly strop the edge on some hardwood at a steep angle a few times and check again - if a burr doesn't "turn up" from that treatment, there isn't one there to see.
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It's kind of funny, I've taken to stropping with a regular 2x4 lately. One time when I was sharpening I noticed that my strop wasn't actually bending the burr back and forth, then I tried with wood and got much better results.
 
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