Don't create a burr

[jackknifeh]

One thought on sharpening is to do many strokes (10 or 20 for example) on one side then the other. This is ok I guess until you are getting very close to getting your edge sharp. At this point I've heard all my life that you need to create a burr on one side to know you have reached the edge and then you need to sharpen the other side to remove the burr creating a sharp edge. After this you need to check for remaining burr's and grind them away. To remove the final, sometimes very small burrs some people use a strop. I have many times. I'm not talking about strops. What I want to discuss is never creating a burr to begin with.

Let's say you have reprofiled an edg to a lower angle. First of all we'll assume the bevels are the same width indicating the edge is in the center of the blade. When getting closer and closer to the two bevels meeting at the edge, I like to stop using more than one, two MAX strokes per side of the knife. When you only perform one stroke alternating each side you shouldn't create a burr on the opposite side. If you do it should be VERY tiny. It will be immediately removed by the first stroke on the opposite side of the blade. At this point your knife is sharp needing only a few final, very light strokes. One major benefit by doing this you will use up less steel moving the edge up into the blade. This subject was brought to my mind by the thread about sharpening too much of your blade until the tip is exposed when closed. This happened to me and the way to prevent it or delay it is to remove as little steel as possible when sharpening. So, when getting close to a sharp edge don't count on creating a burr to indicate you are getting close. Instead cut some paper. If the bevels haven't met, forming the beginning of a sharp edge the knife won't even cut paper. Perform a couple more strokes ONE SIDE AT A TIME and test again. Keep repeating this until the knife cuts the paper. The two bevels may not meet each other along the entire edge at the same time. The area close to the handle may cut good and the belly or tip won't cut. Then spend time only in the areas that don't cut. When the knife cuts the paper from the heel to the tip of the edge you have a sharp knife and hopefully haven't created a burr. If we think about it, the steel that the burr is made up of is just wasted steel. Who want's to throw away expensive steel? Not me. Once you are slicing printer paper cleanly you have a very workable edge. If you want you can continue to refine the edge so it slices phone book paper cleanly. Work some more and you'll be whittling hair. :) To be able to get your edge to whittle hair requires quite a bit of practice so if you are just beginning to learn to sharpen I recommend these cutting tests. Cleanly slicing printer paper by slicing into the edge of the paper is the lowest level of acceptable sharpness IMO. Cleanly slicing into phone book paper is the next step and is definately only being done when the knife is very sharp IMO. If you want it sharper than this you just need to keep practicing what your are doing. I love this quote "practice makes perfect, but it takes perfect practice". Don't practice bad habits. Practice your good habits and improve your bad ones.

kbuzbee made a good point once when talking about the Wicked Edge sharpener. By it's design it automatically strokes one side then the other from start to finish of the process. On my Edge Pro I can lay the blade down and stroke as long as I want just on one side. This is tempting because it's a little faster than flipping the blade every stroke. Free hand sharpening is similar. Stroking only one side is faster per stroke than flipping the blade every stroke. However, the amount of time you MAY save is not worth the steel that may get wasted by creating a burr when spending too much time on one side.

That thread about sharpening your blade away made me think of posting this for anyone who hasn't given it any or much thought. It's not something I figured out because I'm so smart. It was explained to me by a guy I've emailed back and forth about sharpening. Give this some thought and try it if you want. Maybe there's a better or easier way to not use up the steel. If there is I'd love to hear it.

Jack

[Clip]

I'd asked this a little while ago and found some helpful tips. Also, still need to get a sharpmaker.

http://www.spyderco.com/forums/showthre ... sharpening

[Evil D]

I too was taught to always raise a burr. If you search back on my posts here over the years, you'll find me posting about how important it is to make a burr. Oh the things we learn and the mistakes we make. Your best friend here is a good bright light to check for reflection off the edge. If the edge reflects light then the edge hasn't reached an apex yet. Another thing to consider when making several passes on one side or the other is that you can easily throw the center of the edge out of dead center of the blade.

[xceptnl]

I have learned lots here on the forums and with 90% of my knives now when I reprofile I follow the procedure listed below.
(This is for my DMT or similar clamp system, but it still translates)

Have good lighting
Sharpie edge evenly
Secure clamp and check for symmetry
I make one of two passes to ensure I am hitting the shoulder properly (to lower the bevel)
Then I start to progress thru the stones to lower the bevel, but I do NOT completely apex the edge
I go all the way to the polish on my strops to get a mirror finish
Then I finish with the profile stones (both for fine or just the brown for a course microbevel)
The process for me gives great looks (polished bevels) and simple maintenance (toothy microbevel)

I dropped my XHP Manix 2 nights ago from 36 inclusive to 30 and finished with about a 38 microbevel in about 90 minutes while watching TV.

[jackknifeh]

I'd asked this a little while ago and found some helpful tips. Also, still need to get a sharpmaker.

http://www.spyderco.com/forums/showthre ... sharpening

That did mention not wanting to creat a burr. When creating a burr it means you have gone past the apex point so you have removed steel from the side you contact with the stone in addition to the steel that is wrapped around to the other side. Seeing reflection on the edge is only possible when the edge is wide enough to produce a flat surface. Since the sharp edge is not flat, it won't reflect light back at you like the side or bevel will.

I think that the teaching of needing to create a burr is a lesson for beginning sharpeners that we, I know I have, seem to hang on to even as we get better. It's only been within the last 8 months or a year that I was told the theory of just removing steel until you REACH the apex and no more. Removing more steel is when a burr is created.

[jackknifeh]

One thing about not creating a burr is that it's probably impossible to not ever create a burr at all. I just think that no burr is my goal. Dad always told me when I was in school "If you are happy with a B, you had better try for an A". Of course I was happy with a D, so he said "You'd better shoot for the C (as he shook his head :) ). So shooting for NO burr and we make little burrs we are still saving steel. It's the same old "no such thing as perfect" deal. :)

[razorsharp]

I often feel the edge (3 finger test) and when it feels rstravis sharp , i see if it splits a hair both ways. Usually it does and usually there isnt a burr :)

[jackknifeh]

I often feel the edge (3 finger test) and when it feels rstravis sharp , i see if it splits a hair both ways. Usually it does and usually there isnt a burr :)

I'm going to start a thread about Murray Carter's 3 finger test. Most people seem to know about it and have tried it. I didn't understand what I was supposed to feel for when I first tried it but now I "think" I do. Maybe other's will put their experience or opinions of it so more can understand it better. I think it's a good test but it tells you more than just if your knife is sharp. So check out the "Murray Carter 3 finger test" if you like (coming soon :) ).

[chuck_roxas45]

I often feel the edge (3 finger test) and when it feels rstravis sharp , i see if it splits a hair both ways. Usually it does and usually there isnt a burr :)

There's always a burr trav. We may not be able to feel it but there's always a burr if you reach the edge. I guess that's a bit sharper than yours.

http://www.flickr.com/photos/nanofab/86 ... /lightbox/

That's a razor and these are the cut whiskers.

http://www.flickr.com/photos/nanofab/se ... 758928357/

[GTP2K1]

I always think of a burr and sort of way to check your work (should probably clarify and say a burr you can see or feel). But its not the only way by any means. If you know what your doing, know your reaching the edge, know your getting an even bevel an scratch pattern at the current grit, reaching the desired result (presumably very sharp) or have another means to check with a loupe or microscope or simply experience and know-how. Then hey do what works, Jack!

[jackknifeh]

There's always a burr trav. We may not be able to feel it but there's always a burr if you reach the edge. I guess that's a bit sharper than yours.

http://www.flickr.com/photos/nanofab/86 ... /lightbox/

That's a razor and these are the cut whiskers.

http://www.flickr.com/photos/nanofab/se ... 758928357/

As Chuck said there is always a burr even though you can't see or feel it but I think this is due to our limited amount of control. IF and only IF we were perfect we would be able to tell during a sharpening stroke when the stone reaches the edge yet prior to it shoving steel to the other side (burr). Of course this is about impossible. I just picture the microscopic split second when this happens. Since we can't tell when this actually occurs we can only do as good as possible which is to only perform one stroke per side at a time. Hopefully this one stroke, if it does create a burr it will be small enough that we can't feel it. Then we have done about as good as we can I suppose. In the past though I thought I had done some good sharpening when I created a burr that would snag threads on your clothes. :) I had obviously reached the edge and it was time to work on the other side. :D This burr is the steel I hope to keep on my blade from now on.

[xceptnl]

There's always a burr trav. We may not be able to feel it but there's always a burr if you reach the edge. I guess that's a bit sharper than yours.

http://www.flickr.com/photos/nanofab/86 ... /lightbox/

That's a razor and these are the cut whiskers.

http://www.flickr.com/photos/nanofab/se ... 758928357/

Those are great Chuck. Thanks for sharing

[chuck_roxas45]

As Chuck said there is always a burr even though you can't see or feel it but I think this is due to our limited amount of control. IF and only IF we were perfect we would be able to tell during a sharpening stroke when the stone reaches the edge yet prior to it shoving steel to the other side (burr). Of course this is about impossible. I just picture the microscopic split second when this happens. Since we can't tell when this actually occurs we can only do as good as possible which is to only perform one stroke per side at a time. Hopefully this one stroke, if it does create a burr it will be small enough that we can't feel it. Then we have done about as good as we can I suppose. In the past though I thought I had done some good sharpening when I created a burr that would snag threads on your clothes. :) I had obviously reached the edge and it was time to work on the other side. :D This burr is the steel I hope to keep on my blade from now on.

I guess the pinnacle of sharpening skill is to apex cleanly and step off just before making a burr. :D

Those are great Chuck. Thanks for sharing

Just saw those on BF. Can't take credit. :)

But us knife nut darksiders go dreamy eyed over SEM pics of edges. :D

[Clip]

Note to self: make one of these.

http://www.popsci.com/diy/article/2011- ... microscope

[doctorknife]

I totally agree with "jackknifeh". There is no point of removing unnecessary portions of the blade steel. You may not notice it now, but I assure you after a few sharpenings you'll start to. Generally, it depends on what the steel is and how thin is the blade.

And it's a just a matter of technique and patience and whoever doesn't have it, just practice. It will take longer to sharpen a knife without creating a burr but it's preferable.

And on the finest grids, don't put too much pressure. If you are using stones or whatever, just very light strokes. I actually never put pressure even on the roughest grids.

I have the Wicked Edge sharpener, all of the stones for the Sharpmaker and some Norton stones and I never create a burr. Really, never man, and some of my knives are wicked sharp. I just don't need all of them that sharp, they'll soon lose that sharpness after a few cuts. They tend to get that "working sharpness" which is satisfiable by me. Anyway...I hope you all get the point.

[Zenith]

There's always a burr trav. We may not be able to feel it but there's always a burr if you reach the edge. I guess that's a bit sharper than yours.

http://www.flickr.com/photos/nanofab/86 ... /lightbox/

That's a razor and these are the cut whiskers.

http://www.flickr.com/photos/nanofab/se ... 758928357/

I cant say I fully agree chuck_roxas45.

The first image is a stropped blade, overstropping the edge can create such a burr as seen in the image.

Here is another edge image from the same source at the same scale without a burr. However, no info on sharpening information, but one can see it is possible to minimise the burr dramatically. Only if one goes further into the edge you can see even smaller burrs. But that is only really visible at 200um.

http://www.flickr.com/photos/nanofab/83 ... /lightbox/

[chuck_roxas45]

Sure, but technically there is always a burr...

[jackknifeh]

I cant say I fully agree chuck_roxas45.

The first image is a stropped blade, overstropping the edge can create such a burr as seen in the image.

Here is another edge image from the same source at the same scale without a burr. However, no info on sharpening information, but one can see it is possible to minimise the burr dramatically. Only if one goes further into the edge you can see even smaller burrs. But that is only really visible at 200um.

http://www.flickr.com/photos/nanofab/83 ... /lightbox/

Sure, but technically there is always a burr...

I agree. Or disagree? I can't tell. :) I'm wanting to minimize the burr as much as possible so I shoot for NO burr. But as Chuck said there will always be a burr even if we can't feel it with our fingers. To hit the apex AND NOT GO FURTHER ever, would require skill almost impossible for a human person IMO.

[Zenith]

I agree. Or disagree? I can't tell. :) I'm wanting to minimize the burr as much as possible so I shoot for NO burr. But as Chuck said there will always be a burr even if we can't feel it with our fingers. To hit the apex AND NOT GO FURTHER ever, would require skill almost impossible for a human person IMO.

I agree with you. A while back I was adamant on creating a burr while sharpening and since then also try to create as little burr as possible.

I mean take a look at this image and the scale it is. I was wrong with my previous mention of 200um

http://www.flickr.com/photos/nanofab/83 ... /lightbox/

At this stage, giving some thought to what I said previously I have to start asking if what we see at the edge might be carbides or such sticking out and not even be a burr?

If we take into consideration that carbides in O1 can be 0.7um (have a look at this link http://www.hypefreeblades.com/files/schneiden.pdf) at some point we will get carbides at the very apex.

I might be missing the pot completely with my interpretation, but would be willing to discuss.

[defenestrate]

I have found that when I am sharpening regularly, I can hear and sometimes feel what is going on with the edge by the amount of resistance/friction created when making each stroke on the SM. I don't have a loupe and sometimes mess up but I kind of decide on how many strokes I think I should use based on the condition of the edge, type of edge (serrated/plain, likely factory angles for primary and secondary bevel, etc - I may not know the precise number but I can eyeball with good light and there can be a wide range of edge angles from other manufacturers - most spydies are within fairly close tolerances and will "just work" on a SharpMaker), and the more often I do it, the more keen the edges end up. It will be interesting sharpening the waved Matriarch2 for the first time.