Burr Free Sharpening Technique

[SteveG]

Jasonstone, thanks for your explanation!

My understanding how the burr is formed is shown in the attached sketch.

One might think that changing the direction of sharpening from edge-trailing to edge-leading will fully eliminate the burr, but strictly speaking it is not the case, because both burs were formed in a slightly different way. (I consider guided sharpening where the bevel angles are exactly the same for both sharpening directions. Results of free-hand sharpening, where the bevel angles are not exactly the same, may be different.)


 
Jan

In my interpretation of what Cliff is saying, *optimal* sharpening stops the moment the edge is apexed, thus not allowing for burr formation.  I can't argue whether this is true or not, though I can say that I've tried it - unsuccessfully.  Cliff's argument for edge-leading vs edge-trailing is that edge-leading moves damaged metal away from the apex, instead of into it.  His arguments seem to me to be more from the standpoint of edge-retention than achievable sharpness, and from optimal rather than practical sharpening, though his methods seem to work for him - wished they worked like that for me.

SteveG,
That is an excellent explanation.  Could you tell me how Cliff's technique didn't work for you?  This is what I am trying to figure out.  Thank you.

The shaping step seems to be ok for me, so I get to the point where there's no visible light reflected from the edge, and I'm going to apply one or two high-angle passes to micro-bevel and form the apex.  First pass, still dull.  Next pass, still dull.  Keeps on going "still dull" until I can feel a burr - IOW, I'm either not going far enough, or too far, at which point I'm back to the strop just as I would have been if I did my more normal burr-based sharpening, but now that I have a microbevel the stropping is a little harder to get right.

Keep in mind that I don't have much experience at freehand sharpening, and it's likely my high-angle passes are too inconsistent to use this method well, so you'll probably have better results than I get.  Also note that I didn't/don't include back-bevelling (the step where, after adding the microbevel, you resharpen at the original angle to remove the microbevel) in the progression - I might be missing the point, but don't see that it adds any value and just gives me more opportunity to ruin the edge.

So, with all of that said, I can get to slicing phone book paper with the grain, and sometimes across the grain, with this method, but not push-cutting across the grain, which is kinda my threshold for sharp.

SteveG,
I had the same issue when first trying to use it.  I was able to communicate with Cliff and he walked me through the last part.  What I did after that was just take one knife and sharpened it for a week until I got the technique down.  In Cliff's video and forum post, he didn't explain that he had sharpened the knife in the video several times before so it looked a lot easier than it was.  

Here are the steps to the 3-Step Method:  

1. After the shaping stage, the knife should slice newsprint, and after apexing it should push cut.  With a knife that you are familiar with or if you can feel the feedback from the stone, this isn't that difficult as the edge feels a certain way on the stone right before it forms a burr.  I usually am not big on counting passes, but if I haven't sharpened a knife before or I can't feel the feedback on the stone for some reason, I will do sets of 5 or 10 passes per side until the edge slices newsprint (this is right after the shaping stage were the edge is no longer reflecting light).  

2. Then I will double the angle and set the apex, usually 5-10 alternating edge leading passes per side, then lower the angle to the original angle and do 1-5 passes alternating passes per side, checking  for sharpness.  

3. If the edge is not push cutting newsprint/phonebook paper by then, I check to see if there is a burr.  If no burr, I will do a few more edge leading alternating passes, again checking the sharpness.  If there is a burr, I repeat step 2, then check sharpness.

I have noticed that one of the issues that is causing problems, and the one I had, is going straight for no reflection of light to micro-beveling, and either not doing enough passes or overginding and forming a burr.  When I asked Cliff how to avoid overgrinding and forming a burr(that is the point of this technique, right?), he told me don't worry about forming a burr, just cut it off with the micro-bevel.  Another issue is that some try Plateau Sharpening first before they get the 3-Step method down, which is using one stone for shaping, doing alternating passes until the edge shaves while stopping before a burr is formed, and then apexing the edge with a micro-bevel.  This is a lot more tricky of a technique, as you need to double or triple the number of micro-bevel passes, and it doesn't give you the opportunity to do a lot of grit progressions, unlike the 3 Step Method, where you can insert as many stones as you like to get a mirror polish.

jasonstone,

  Thanks for the thoughtful and detailed explanation, I will incorporate that into my practice sessions.  I think your advice, as with most of the sound advice I hear, is to practice, and with practice will come success.  I've heard Cliff claim that anyone can learn this method in a very short time (don't remember for sure, but I think it was denominated in minutes); I've also read where someone mastered it in a year.  For you it was a week.  For me, it's not been dedicated practice, but I did buy a cheap paring knife to practice with, and once every week or so I'll give it a spin, so maybe in six months or a year I'll be wondering why it was so hard to figure out. 

  So, one question: are you applying the microbevel with the same stone you shaped with?  Actually, a second question: are you also back-bevelling with the same stone.  It sounds like you are; I've done it both with the same and with a finer stone (which is what I think you're referring to as Plateau Sharpening) - which points out one of my significant flaws in practicing (i.e., that I usually try something different each time I practice, which maybe means I shouldn't be calling it "practice").

  Thanks again for the tips, I'll be playing with those.

  Steve