Friday 7 June 2019

Burr On - Burr Off




     Greetings,

   One of the grey areas for me that popped up many years ago involved Burr Formation, The question at that time was "Do I need to form a burr on every stone that I use and if so, why?"

     The answer came to me and for the last 8 years I have been quite convinced that Burr Formation should happen once, on the first stone, on each side of course and then everything after that involved the removal of the Burr.


   

     Recently something popped up on Instagram from a fella that I know is a very good sharpener and he mentioned that he forms a burr on every stone. My immediate thought was that he is wrong and that this is just wasted metal removal. 

     Now, something that is important to me is to be willing to learn and accept new ideas about sharpening and be open to various approaches because there is always a chance that something may pop up that is beneficial and could make my edges better. 

     One of very cool things about knife sharpening is that there is no   "One Technique Rules".  If the process being used results in the removal of fatigued metal, burr formation and re-establishment of the primary edge and burr removal then that's a sound technique. Whether it is freehand sharpening, using a jig like the Edge Pro or a belt sander and a combination of all these things, they can all make a dull knife sharp.

   With this in mind, and my ego well in check as it always is, I looked into this burr formation on not just the coarse stone but even the finishing, 5k and finer stones. What the hell is going to happen if I form a burr on the Kityama 8,000 when for the past 10 years I strove not to form a burr but to continue to clean the edge by ever diminishing levels of pressure?




    I reached out to a couple of highly respected, gifted sharpeners to get their thoughts, one is for it and the other against it. So since one is for it and does it, it was only natural for me to give it a shot and see if I have been wrong all these years.

   Well after many knives, I can tell you that I was not wrong, however, both approaches do absolutely work and in fact I like the burr forming on every stone method now.  I'll explain how it works but know that it's not something you need to adjust to, as I said, both methods work. 

   Remember that the reason I didn't form a burr on the 1k stone for example was that I was thinking it means excess metal removal. I no longer think that way, my brilliant friend Jon told me that it is a very acceptable loss. The method actually involves some additional skill because these additional burrs need to me very very subtle, tiny little burrs so with this in mind you can actually fine tune your sharpening skills by striving to form these micro-burrs.

    This method does ensure that you are reaching the edge of the edge on every stone and if you try it, remember that the goal is to form exceptionally small, hard to detect burrs.





This new approach, for me, involved very little change to my current process, in fact, it is simply a matter of using just a little more pressure on the stones.   So we can call the first burr formed on the first stone: Burr Number One or, Primary Burr, it doesn't matter but this is the one that is  given, it is must.

   In my opinion, burr formation and burr removal, especially burr removal are the most important parts of knife sharpening, we need to clean that edge off, get rid of that burr.

So now all I do is when I reach the 1k stone after a 400 or 500 grit Primary Burr forming stone, I just use a little more pressure to form the burr on the 1k stone. It doesn't take much and in fact I now know that I was really forming burrs in the past anyway, many times on my knives, I just wasn't actively trying to detect them.








       If I moved from the 1k to a 5K finishing stone, in the past I would use 3 levels of pressure to remove the burr. I still use 3 levels of pressure on every stone after the first coarse stone, I just tweak the first P3 level of pressure to form a tiny burr and  believe me, it doesn't take much. I am no longer concerned about removing too much metal as this is just not the case if I am being careful.

    Now, how does this impact the edge in terms of edge stability, retention?  To be honest, I do not know yet if this approach makes the edge weaker or stronger, I don't see the science behind it, I don't see how it will influence things either way, not yet.

    Now how does it impact the edge in terms of sharpness. Again, my edges are edges that I have been very happy with in the past but I am also quite happy with the level of sharpness using this new (new to me that is) technique. The knives are freaking sharp, that's all I can say.


    The purpose of this post is not to try to steer anyone in a different direction, not at all. I am simply pointing out that it works, as other methods do but I was wrong in thinking that I can't form burrs after the coarse stone, I have done it many times recently and can only see positive results. 

    Some folks use edge trailing strokes like me, some use edge leading and others use both, pressure both ways. Some using a sweeping motion working the entire length of the blade while others, like work in sections using two fingers to apply pressure. 

    There are no absolutes, don't be afraid to try something new, as long as the primary goals of burr formation and burr removal are being met, the knife will get sharp.



    If I see any concrete evidence that this technique is detrimental in terms of edge retention over the next several months I will let you know.

   Thank you, I appreciate you visiting my Blog.
Peter Nowlan
Nova Scotia