Edge chipping on a cheap knife
- This topic has 8 replies, 6 voices, and was last updated 01/15/2017 at 2:04 am by
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It could be that the knife has invisible stress cracks form a life of being abused and the diamond stone is merely breaking off chunks that would come off in time with any means of sharpening or thinning. There have been several discussions in the past on this forum about flattening the edge completely to get to new solid metal. Then re-sharpen as close to even on both sides as possible.
Similar chipping happens with a blade that has been overheated on a mechanical grinding wheel without coolant and somebody polishes out the heat discoloration to cover their mistake. Another cause is using the knife as a pry-bar near the edge (my wife would do that), or improper use of a steel.
Personally I would not go less than 18 degrees on a cheap knife then add a 20 to 22 degree micro bevel.
On the other hand the knife may be poorly heat treated and never be worth the effort except for the learning aspect. Inexpensive knifes are batch heat treated and this one may not have been in the right place to get a proper heat treatment.
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tcmeyer, you say you never apex with stones under 400 grit. Well how the HECK are you developing an edge then? You mean that you are continuing to try and reprofile knives with 600 grit stones and higher? If I’m understanding correctly, doesn’t that correlate to spending ungodly amounts of time in reprofiling? I’m honestly confused, because I thought the point was to apex at the beginning grit and then continue to refine / polish the edge as you go through the stones…?
Please understand that I am stating what I have found to be best practice for me; a position I guess you ought to assume for anybody’s personal experience. I will use my 100/200 grit stones to reprofile, but I carefully watch how closelyI am approaching what I expect to be the final apex. This works best for me when I flatten the edge to eliminate any deep chips and dents. I can then judge pretty accurately where the final apex will fall and then approach it carefully.
No, I don’t limit myself to the 600’s, but because of the heavy use my 400’s see, they are very well “broken in” and there is little concern about further damage to the apex. Of course, this practice means that I heavily use my 400-grit stones and have to replace them more frequently because of it. The deeper the damage is, the longer you’ll have to work at removing it with your least destructive stone. For me, that’s the 400, and yes, sometimes I spend a lot of effort with my 400’s to achieve the first stages of a refined edge.
The root of this approach is that I think you’ll find that removing the last bit of scratches from one grit before proceeding to the next and refining the edge are two different animals. If your intent is to leave a “toothy edge,” this is pretty much irrelevant, but achieving a hair-popping HHT4 edge will require much more focus on removing flaws at the apex left by a previous grit.
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