I am sharpening my Z-cut plain edge knife today and the edge keeps crumbling. See picture below. When I examine the apex, little microchips are visible. When I ‘reprofile’ the knife on the medium rods of the sharpmaker I hit the apex and remove some steel but the edge with ‘fresh’ steel will crumble again. I don’t use much pressure.
I am really not a pro at sharpening but with all my other knives (> 50) i had no issues like this. There must be something that I am doing wrong or can it be the heat treat of BD1N or is the edge burned at sharpening at the factory?
Really need some help here from you guys who are more experienced.
Well there is one thing you do want to keep in mind. I used to work in a machine shop with two journeymen who really knew their stuff. And both of them told me that there is no such thing as a true plain edged knife. All knife edges they said had some degree of serrations no matter how well honed they are. In other words all plain edged knife edges have peaks and valleys along the edge when you view them under high magnification.
I've found that out to be true even by doing my finishing work with stones up to 8000 Grit. It's a completely different world under high magnification.
It might also be edge burn from over zealous sharpening at the factory. Once you get to metal unaffected by that the edge will likely be okay. I had a knife like that once and got disgusted with it. Someone told me to take the edge down aggressively to get to new metal. I did and all was well afterwards.
Mine was worse than yours. If I had yours I’d just use it and sharpen as needed knowing things will sort out in time.
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Mine had all kinds of high and low spots to sharpen through. It was a pain especially since the blade likes to flex so much and disappointing for a brand new knife but the price was right and working great now that there's an edge.
Well there is one thing you do want to keep in mind. I used to work in a machine shop with two journeymen who really knew their stuff. And both of them told me that there is no such thing as a true plain edged knife. All knife edges they said had some degree of serrations no matter how well honed they are. In other words all plain edged knife edges have peaks and valleys along the edge when you view them under high magnification.
I've found that out to be true even by doing my finishing work with stones up to 8000 Grit. It's a completely different world under high magnification.
I agree that there will always be some degree of serrations on knives. Especially under high magnification. This Z-cut however has very noticeable ‘serrations’ I rather call chips. It prevents a clean cut even through normal paper. And yes I am an edge junky. :eek: I like my knives extremely sharp. Don’t mind sharpening every day. Find it kind of relaxing. Except this time...
It might also be edge burn from over zealous sharpening at the factory. Once you get to metal unaffected by that the edge will likely be okay. I had a knife like that once and got disgusted with it. Someone told me to take the edge down aggressively to get to new metal. I did and all was well afterwards.
Mine was worse than yours. If I had yours I’d just use it and sharpen as needed knowing things will sort out in time.
I think this could be indeed the case here. Thought about using it and sharpening it after use regularly. Still I find myself wanting to fix the problem before using it again.
Two reasons for this:
1. The knife doesn’t cut very well at this point. The chips in the knife become sticking points.
2. Can’t believe it that the chips remain in the steel. It’s BD1N, not Maxamet. I keep thinking, sharpening must work eventually.
I understand what you mean with getting disgusted with the knife. In my case, not the Z-cut as a model, they are fantastic little slicers, but with this specific piece.
Addition: I think I will go aggressive on this metal too. Time for the diamond rods. :D
Mine had all kinds of high and low spots to sharpen through. It was a pain especially since the blade likes to flex so much and disappointing for a brand new knife but the price was right and working great now that there's an edge.
The flexibility of the knife is barely noticeable when I sharpen it on the brown rods. I use very light pressure. I can image tough when using the diamonds rods the knife will flex more due to the coarser abrasive. Something i will keep in mind when i go in ‘aggressive’ sharpening mode.
When the edge is repaired and stable again the Z-cuts are great tools for their price. Can’t help it, but there is always a smile when I cut things with that little :spyder: on my tool.
All 4 zcuts of mine are fine, but have had other knives that’s had this issue. All eventually straightened out with repeated sharpenings. Some took more metal removal than others.
All 4 zcuts of mine are fine, but have had other knives that’s had this issue. All eventually straightened out with repeated sharpenings. Some took more metal removal than others.
Done! It took me a while to do all the repeated sharpenings at once. The edge is not yet fully repaired, however it is at a level of sharpness i can live with. This was a whole new experience for me. Never had such a chippy knife before, I know its not the steel by itself. Maybe i just had some bad luck with this one. On the other hand i learned something new here. Patience to keep sharpening the knife until fresh metal appears. Because initial sharpenings led to more chips in my knife i almost gave up on it. From a different steel i could have expected this behaviour due to possible carbide tear out. BD1N is (correct me if i am wrong) a fine grained steel. Did not expect the BD1N edge to behave like this.
