# Burrs



## gic (Sep 23, 2013)

Because my fingers lack sensitivity, I always have trouble feeling a burr. So I resort to various tricks like cheesecloth or a q-tip but none give me the assurance I would get by actually seeing the burr under magnification.

Can anyone provide me with links to actual images of what burrs look like under magnification so I can compare them to what I am seeing? 

Is there an optimal way to hold the knife to see a burr under magnification? 

Finally, for a typical sized burr would 20X be enough to see it clearly?

TIA


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## tripleq (Sep 23, 2013)

Wow. That's an interesting scenario. I'm afraid I can't offer and direct answers to your questions but as a means of discussion I'll offer the following. 

If your fingers lack sensitivity, have you tried assessing a burr with any other part of your hand? Knuckle? Wrist?

Personally I sometimes have trouble feeling burrs on very fine stones so I only know it is there because it feels or sounds different from the opposite side. Maybe a side to side comparison might help? 

As for comparing burrs to existing photos is it because you don't know what one looks like or because you just want to compare your burr against someone else's? In the case of the former I can't think of any resources. In the case of the latter I think it might be a bit of a misleading practice. Different people will produce different burrs using the same stone and knife. If you have seen a magnified photo of any burr or know what one is supposed to look like you'll definitely see it if it is there. I'm not sure you'll gain and advantage in comparing it to anything else.


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## Ruso (Sep 23, 2013)

I looked at burrs under the microscope just for fun and I have much easier time detecting it with my fingers then under the microscope. 
Did you try non-dense cotton ball?


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## Squilliam (Sep 23, 2013)

Cut tissue. Any snagging or tearing with an otherwise sharp edge indicates a burr or some other issue.

You should be able to see any burr off a 2k or coarser stone with the 20x loupe under a bright light. Beyond that, cut tissue and then strop on bare leather until the edge stops improving. As long as your stropping technique is okay, IMO you can't over-strop an edge on bare leather.


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## Justin0505 (Sep 23, 2013)

Even under pretty high magnification a bur can be pretty tricky to see. It often just looks like a thin silver/ white line that reflects light differently than the steel on the rest of the bevel.

There are 2 scenarios in which I typically want to detect the presence of a bur. 

1) While sharpening inorder to tell when I've reached the edge and it's time to sharpen from the other side.
This, IMO is the easiest type of bur to detect because it's folded over to one side (the side opposite of where you were just sharpening). I can usually feel it with my finger tips, but fingernails are also useful in detecting it.
One method is, with the edge pointed down, parallel to the floor press a fingernail into the side of the blade just above the edge and then scrap downward. You can either do this with your palm facing downward or upward (i think upward might be easier b/c you nail has more flex in that direction). Once you know what it feels like (by comparing it to the non-bur side as well as known, very large burs) it's pretty easy to recognize.
Another method is to "strop" the edge on a thumbnail. BE CAREFUL. If you do this properly there is no risk, but anytime you're rubbing a blade over a part of yourself, there is danger if you're not paying attention / using good technique. I start with the edge pointed toward my hand, place the side of the primary edge bevel near the back of my nail and very lightly and slowly move the knife away from my hand in an edge-trailing direction. The burred side will grab and possibly even slightly scrape your nail leaving failt white scratch marks.

2) After I'm done sharpening and stopping / polishing and I want to make sure that there is no bur left.
In this case it can be very difficult to see or feel a bur because it's very fine and also aligned with the edge (as opposed to rolled to one side when sharpening). The only method that I use other than feel is to draw the blade though some clean, soft, light-colored wood and see what it does (or doesnt) leave behind. A dark grey line in the wood mean that there is / was a bur and that you need to draw it though a few more times until the line looks clear.


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## CrisAnderson27 (Sep 23, 2013)

Justin nailed it .

I strop on my thumbnail when I can't visibly see a burr...and draw through a dense piece of balsa.


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## gic (Sep 23, 2013)

Thanks so much guys, I really think the amount of knowledge on KKF is amazing! I'm going to try all of the tips mentioned above and see what works best for me...


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## EdipisReks (Sep 23, 2013)

I always "strop" with a fingernail, and you can feel the blade drag even with reduced finger sensation (I have that issue in few fingers due to cuts I've sustained over the years).


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## Dave Martell (Sep 23, 2013)

Burrs will glint in light so they're pretty easy to see. Wire edges can't easily be identified even with magnification. 

Remove all burrs seen by cutting into something that's self-healing in nature like dense felt, cork, or soft wood and then reduce your wire edge through finer grit abrasion.


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## jared08 (Sep 23, 2013)

Dave Martell said:


> Remove all burrs seen by cutting into something that's self-healing in nature like dense felt, cork, or soft wood



What does the "self healing" aspect of the material play?


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## Dave Martell (Sep 23, 2013)

jared08 said:


> What does the "self healing" aspect of the material play?




Self healing material grabs the edge through a squeezing action from the sides vs just cutting open a slot. I've found the best deburring materials have great self-healing properties, the denser the material the better. Cleaner edges done faster. Of course the material being used also can't dull the edge....that's pretty important and often overlooked.


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## CrisAnderson27 (Sep 23, 2013)

Dave Martell said:


> Burrs will glint in light so they're pretty easy to see. Wire edges can't easily be identified even with magnification.
> 
> Remove all burrs seen by cutting into something that's self-healing in nature like dense felt, cork, or soft wood and then reduce your wire edge through finer grit abrasion.



I think that's my next real challenge...is making sure I don't have any sort of wire edge going on. I do my best with what I have...but I'm sure there may be residual fatigued metal left.

I haven't been brave enough to try your method yet lol...but I probably will start doing something like that here shortly.


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