Hi everyone,
I am new in this forum, so forgive me if I ask stupid questions.
I tried to find answers for my questions, but maybe not looking in the right place.
After almost 50 years of sharpening knives I still struggle with the concept of the *burr*:
(i) Assume one sharpens from the spine to the edge of a knife: the wheel causes an abrasion of the steel; as the abrasion 'rips out' tiny particles of metal, some of the steel will get smeared in direction to the edge (like butter on bread) and forms a tiny lump - the burr.
(ii) if the knife is turned to the other side (still spine-to-edge), the same occurs. Why is there not another burr from the other side? There is only one burr - is it the agglutination of two burrs? As there is no thermic forming because of the low speed and the water cooling, how can this happen?
(iii) Assume grinding from the edge to the spine of a knife:
assuming the butter-on-bread assumption in (i) is correct, there shouldn't appear a burr on the edge but instead maybe something more in direction of the spine. BUT there IS a burr at the edge!
(iv) This seems to imply that the butter-on-bread-smearing analogy is wrong for edge-to-spine grinding (at least). But where does the burr then come from? Is it metal that is pressed by the turning wheel 'over' the apex of the edge such that it agglutinates on the other side?
(v) If this would be true, we would have two different types of burr - at least from their origination (and possibly to be corrected by differing procedures) ...
I am new in this forum, so forgive me if I ask stupid questions.
I tried to find answers for my questions, but maybe not looking in the right place.
After almost 50 years of sharpening knives I still struggle with the concept of the *burr*:
(i) Assume one sharpens from the spine to the edge of a knife: the wheel causes an abrasion of the steel; as the abrasion 'rips out' tiny particles of metal, some of the steel will get smeared in direction to the edge (like butter on bread) and forms a tiny lump - the burr.
(ii) if the knife is turned to the other side (still spine-to-edge), the same occurs. Why is there not another burr from the other side? There is only one burr - is it the agglutination of two burrs? As there is no thermic forming because of the low speed and the water cooling, how can this happen?
(iii) Assume grinding from the edge to the spine of a knife:
assuming the butter-on-bread assumption in (i) is correct, there shouldn't appear a burr on the edge but instead maybe something more in direction of the spine. BUT there IS a burr at the edge!
(iv) This seems to imply that the butter-on-bread-smearing analogy is wrong for edge-to-spine grinding (at least). But where does the burr then come from? Is it metal that is pressed by the turning wheel 'over' the apex of the edge such that it agglutinates on the other side?
(v) If this would be true, we would have two different types of burr - at least from their origination (and possibly to be corrected by differing procedures) ...