12-06-2017, 10:11 AM
This thread just struck us right in the mid-section and here's why; We were very recently exploring some potential new burr removal techniques and came across a very peculiar situation. We had been looking at the relationship between grind techniques/materials, burr formation and burr removal. This research fits well with our general sharpening philosophy here in that we feel "it's all about the burr".
In this instance we were using our Kally 1SM with a 180 grit ceramic belt with a custom angle guide attached. We were sharpening a brand name stainless steel knife of some reasonable quality. This is an "edge trailing" methodology. We produced several easily detectable and substantial burrs on this knife and then conducted our experiments. After a while we changed things up and decided to begin with a really dull edge. We ran a ceramic rod, 90 degrees to the edge, straight down the edge. This was interesting in itself because our optical microscope indicated that the ceramic rod had created a burr (or something that certainly resembled a burr) on both sides of the edge. Then we returned to our grinding and here is where the mystery began. No longer could we raise a substantial burr. At first, we thought we weren't raising a burr but on closer inspection discovered exactly the kind of burr that you gentlemen are discussing. Flimsy beyond belief and removed only with great difficulty. Additionally, and once the burr was removed, our edge tester readings were 50-60 points higher than we had been achieving previously. This all remained the same through two additional grinding efforts. It was if we had, literally and in some way, managed to change the very character of the steel.
We don't have an answer, perhaps a few theories, but mainly, just this perplexing story. You may say that this is much like the patient who told his doctor that he had broken his arm in seven places. The doctors advice to the patient was to "stay out of those places". In keeping with the doctor's advice we may not run ceramic rods down the edge of knives any longer but it does make us wonder how this might relate to the topic that is being discussed here and how all this might tie to general sharpening/burr removal knowledge and technique.
In this instance we were using our Kally 1SM with a 180 grit ceramic belt with a custom angle guide attached. We were sharpening a brand name stainless steel knife of some reasonable quality. This is an "edge trailing" methodology. We produced several easily detectable and substantial burrs on this knife and then conducted our experiments. After a while we changed things up and decided to begin with a really dull edge. We ran a ceramic rod, 90 degrees to the edge, straight down the edge. This was interesting in itself because our optical microscope indicated that the ceramic rod had created a burr (or something that certainly resembled a burr) on both sides of the edge. Then we returned to our grinding and here is where the mystery began. No longer could we raise a substantial burr. At first, we thought we weren't raising a burr but on closer inspection discovered exactly the kind of burr that you gentlemen are discussing. Flimsy beyond belief and removed only with great difficulty. Additionally, and once the burr was removed, our edge tester readings were 50-60 points higher than we had been achieving previously. This all remained the same through two additional grinding efforts. It was if we had, literally and in some way, managed to change the very character of the steel.
We don't have an answer, perhaps a few theories, but mainly, just this perplexing story. You may say that this is much like the patient who told his doctor that he had broken his arm in seven places. The doctors advice to the patient was to "stay out of those places". In keeping with the doctor's advice we may not run ceramic rods down the edge of knives any longer but it does make us wonder how this might relate to the topic that is being discussed here and how all this might tie to general sharpening/burr removal knowledge and technique.