Burr Free Sharpening Technique

[Jan]

I enjoy the fruitful discussion in this thread. Every post may be the missing stone in the mosaic how to proceed efficiently when deburring an edge.
 
It's a temptation to find universal rule how to sharpen without a burr. In my understanding the burr formation process is not fully understood yet. It depends among others on physical properties of sharpened blade. The most important property is the ductility/brittleness of the blade. Ductile materials form large positive burrs while brittle materials form smaller negative burrs by break out mechanism.  
 
Nevertheless it is surely worth to look for a simple approach how to minimise the burr which is to some degree unavoidable phenomenon of sharpening.
 
Jan

I never thought of "negative burrs" as a way of expressing that concept - nice!  

Two other things worth noting (maybe, I'm not the most qualified observer here):

  - Most of the people I've heard of doing this method are using very acute sharpening angles, so even their high-angle passes are often lower than what I use regularly (20dps).
  - A point that's often emphasized is that the stone needs to cut. Sharp, fresh grit, otherwise you're just smearing/damaging the metal.  I've often wondered with edge-leading if that doesn't lead to the "negative burr" you referred to.  For me, as you alluded to, different steels respond dramatically to different stones.

Steve G, I have not invented the terms "positive and negative burrs", I saw it used in papers concerning machining.

Both, positive and negative burr can develop in an edge-trailing regime depending on ductility/brittleness of the sharpened blade. The attached picture schematically explains the burr formation process.

   

Jan