S30V Native - eternal wire edge??

That's been my gospel for years, but in this case I had to elevate the grind angle to approx 25 degrees and take the burr off with an extremely light touch (still required several passes/side) before finishing w/ a few passes at 12 degrees. I think I had a couple of things happening - fatigued metal at the edge was the biggie and I'm pretty sure it came that way, and harder steel than I usually come across. I can recall having to scrape a burr off once before in this manner, I think it was one of the Benchmade balisongs. I'll have to see how it holds the edge, but I suspect this is some long-wearing stuff.
 
Nope, it's doing it again. Wore the edge down pushcutting paper and cutting cardboard. Touched it up on the E.P. starting with the 1000 grit and by the 6k polish tape I was getting edge rolling again. Cut through some wood and the edge looked torn up. I might go with what knifenut said in a different thread and keep the edge toothy. Really disappointing though because the Native is an absolute pleasure to sharpen on the E.P.
 
Have you tried the microbevel?

Things can start to get very complex when you sharpen to such a high grit and even more so when you have perfect geometry. Pressure can be a killer and from your rolling description it sounds like too much pressure is being used. Pressure causes the abrasive to dig deeper into the steel causing greater rates of deformation, when this liquid like steel reaches the apex of the two bevels it sticks and extends off as in essence it turns back into a solid.

With the finishing grit used and angles held in such tight tolerance I would expect if properly done edge widths of 0.3 microns or less. That's extremely small and in the league of your disposable razor. You also run into the issue of this very fine edge being poorly supported by the metal behind it due to the straight V shape. Its easily damaged by lateral forces and abrasion of the cutting edge seems to be more dramatic. Being that the edge is so fine you will also notice ANY damage and yes paper will damage a edge like that.

Due to the bevel type you are applying its nearly a must that you apply a microbevel to add proper support too the cutting edge.

The last factor and one I've been playing with for some time is what grit to finish at. If sharpening with diamonds 600-1200 seems to be a nice finishing point with the 1200 grit leading in performance and the 600 being the more aggressive cutting edge. I have had some limited experience with water stone edges and so far I am liking what natural stones do but did get good results from my 8k stone. The natural is a Awase To, 8-10k finishing stone and with this "hard" metal produces a white haze on the bevel with no visible scratch. Surprisingly it cuts the S30V without issue but the best part is the resulting edge. Its very sharp but in a much different way, the edge simply cuts in all directions and displays sharpness greater than what the feel leads you to believe. The edge also seems to be holding up well but I will need to cut up some more things to get a better feel for it.
 
knifenut1013 said:
Have you tried the microbevel?

Things can start to get very complex when you sharpen to such a high grit and even more so when you have perfect geometry. Pressure can be a killer and from your rolling description it sounds like too much pressure is being used. Pressure causes the abrasive to dig deeper into the steel causing greater rates of deformation, when this liquid like steel reaches the apex of the two bevels it sticks and extends off as in essence it turns back into a solid.

With the finishing grit used and angles held in such tight tolerance I would expect if properly done edge widths of 0.3 microns or less. That's extremely small and in the league of your disposable razor. You also run into the issue of this very fine edge being poorly supported by the metal behind it due to the straight V shape. Its easily damaged by lateral forces and abrasion of the cutting edge seems to be more dramatic. Being that the edge is so fine you will also notice ANY damage and yes paper will damage a edge like that.

Due to the bevel type you are applying its nearly a must that you apply a microbevel to add proper support too the cutting edge.

The last factor and one I've been playing with for some time is what grit to finish at. If sharpening with diamonds 600-1200 seems to be a nice finishing point with the 1200 grit leading in performance and the 600 being the more aggressive cutting edge. I have had some limited experience with water stone edges and so far I am liking what natural stones do but did get good results from my 8k stone. The natural is a Awase To, 8-10k finishing stone and with this "hard" metal produces a white haze on the bevel with no visible scratch. Surprisingly it cuts the S30V without issue but the best part is the resulting edge. Its very sharp but in a much different way, the edge simply cuts in all directions and displays sharpness greater than what the feel leads you to believe. The edge also seems to be holding up well but I will need to cut up some more things to get a better feel for it.
Click to expand...

Good reminder with the microbevel, I wasn't thinking about that. Very little pressure was being used- I was sharpening sitting down again and was purposely using a fine touch to prevent any issues. I think I might just microbevel and report back later.

Oh, and you're completely reading my mind. I've been eying the 10,000 grit Chosera E.P. stone for weeks now but can't justify it's high cost. But damn- mirror bevels from a high quality water stone- just wow. (The zknives guy reviewed it here and his conclusions were "extremely positive")
 
I would like a set of chosera's especially the 10k but at that price I think I'd rather buy a natural. I've heard the chosera's feel like naturals though so IDK. I'm sure it would be very nice on the EP, I'd say go for it :)
 
A few minutes with the 2k/6k polishing tapes and the resulting microbevel was a hair-popping paper-dividing, cutting machine. Thanks again knifenut.
 
You should get much better performance now, and good job at doing the micro correctly.
 
Nope. Attacked the Native with my new goodies including UF diamond stone all the way down to 0.3 micron PSA lapping film and the feather edge remained under the microscope as well as failing the newspaper cut test. Yet my Benchmade and Buck blades in s30v easily took a scary mirror edge. No more excuses, there's something wrong with this Native. The question is: should I get it heat treated or return it?
 
BladeChemist said:
Nope. Attacked the Native with my new goodies including UF diamond stone all the way down to 0.3 micron PSA lapping film and the feather edge remained under the microscope as well as failing the newspaper cut test. Yet my Benchmade and Buck blades in s30v easily took a scary mirror edge. No more excuses, there's something wrong with this Native. The question is: should I get it heat treated or return it?
Click to expand...

Have you done a flex test on the edge?
 
knifenut1013 said:
Have you done a flex test on the edge?
Click to expand...

No testing as of yet. I'm not familiar with the flex test, nor any other at-home tests. I will say though that this particular Native's s30v definitely feels "softer" than the BM/Buck versions. As in, on the course stones you can feel the 'crunch' of the grit with the BM/Buck versions but with the Native there is a definite softer sound/feel. I mean, wow- if this is the extreme end of toughness then good for it, but this is the third or fourth sharpening session with my Native and it has always delivered that darn feathered edge. Especially frustrating when my other s30v knives consistently give me that hair popping edge starting at ~320 grit and upon polishing there's just this scary, scary sharp edge..and then of course the Native with it's mirror polished bevels and that mocking feathered edge.

I do wish there was an easy at-home hardness test to see if this was just one of those knives that had the bad luck of finding itself in the cooler zones of the furnace.

P.S. I'm going to go try some 0.1 micron diamond PSA film on that edge to see if that has the ability to rip through...
 
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