Habeas Corpus said:
Among the differences I noticed so far are that ZPD-189 is even easier to sharpen than VG-10. That's kind of amazing, considering that VG-10 is already very good in that respect, much better in my experience than, for instance, S30V. But I also noted some microchipping that I never had with VG-10.
It's weird. I didn't have that problem the first sharpening, which was a very minor touchup, but I started to have it down the road (the opposite of how burring problems usually work). It could have been worse, but you know it's happening when there is no edge burr but for some reason the edge just won't take that very last bite. But it would still get very sharp quickly, just not wuite as sharp as the factory edge.
With even more sharpening and a lighter touch on the stone, I improved the edge even closer to the out-of-box condition. Then I cleaned the stones on my sharpmaker, giving them the best cleaning I had bother with so far. That did it. With nice bright white clean stones, I got that super sharp edge.
That too was weird because the unclean stones that wouldn't restore the ZDP189 seemed to still be doing OK on VG10.
That's after using my burgundy Calypso Jr. for a couple of weeks for typical household stuff, that is no really hard cutting. Alright, it wasn't *that* much microchipping and easily sharpened out, but the damage to the edge was easy to see at 6x magnification. My gray Calypso never showed that kind of damage after much harder cutting.
It's a little disappointing to have that happen, but even with the very small micro chipping ZDP189 seems to hold a very sharp edge for a long time. For anyone who doesn't have a ZDP189 calypso, we are talking about "chips" you don't see with the naked eye.
s30v's edge burring under sharpening and use is also disappointing, though again only relative to what a steel could be. It's still very good stuff.
If you are having trouble with the s30v, do two things:
First, give it a long thorough sharpening with diamond stones at a low angle (30 degrees total on a sharpmaker). If the edge is "bad" from fatigue or who knows what (including a careless sharpening job resulting in a forced burr), it adds to the burring problem and makes sharpening difficult. s30v is extremely resistant to wear, so it takes more sharpening to get rid of that compared to other steels.
Second, once you are rid of the bad steel on the edge and sharpened it carefully to avoid damaging the edge, add a micro bevel, maybe a little more of a micro bevel (removing more steel total) than you would with other knives, at a higher angle (40 on sharpmaker). Be VERY careful when adding the smaller bevel, as you don't want to bend the edge and ruin your previous efforts. Depending on how much edge burring you are inclined to notice or care about, you way even want to change that to a steeper angle. I tilted my Native blade a little bit to increase that, and results are more satisfying.
With careful sharpening, you will notice s30v's advantage of being very fine stuff. Even when bent, the steel remains very smooth, but with an adequate micro bevel you can really reduce that. It also wears down very slow, so if you use a steeper final edge angle you can really make use of its benefits while reducing its disadvantages compared to harder steels.
Cliff complained about the Sebenza (s30v) having a thin edge with a steep final bevel. After working out the "optimum" (yikes!) edge profile for my s30v native, that popped back into my head and I was thinking maybe Chris Reeve has the right idea. Of course, a micro bevel arrangement would be better and I would have to see the Sebenza in person to know how it is working out.
A side note, going back to s30v taking longer to get rid of fatigued steel on the edge, that's pretty much why Carbon and tool steel fans don't care much for stainless. What a good Carbon steel can do with high hardness (that "what" being remaining in good cutting form), a lot of the popular stainless steels try to do with higher resistance to wear. You could conceive of a stainless steel and a Carbon steel which acheive roughly similar performance like this (just imagine the edge burr on the stainless equaling the width of the worn area on the Carbon steel). But burred steel is weakened and tends to flip flop when sharpened. So then to get rid of enough steel to restore both to equal sharpness, which steel is going to most resist wear from the sharpening stone? Depending on the exact steel and hardness in question, you will either take a lot longer to sharpen the stainless (like s30v), or else sharpen it as fast and have constant new edge burrs forming. That clears up the mystery people run into who are familiar with stainless and hear that Carbon steel is easier to sharpen and lasts as long, or even lasts longer (depending on the steel in question and how the advantages are spread). So it's no surprise that a lot of people who are acustomed to stainless are big fans of the enduring and smooth s30v and notice mainly its improvements, while fans of tool and Carbon steels (like me), waiting for popular stainless steels and millions of dollars of fancy technology to catch up with non-stainless steels, try s30v and think "well, it's better than ats34 but it's still another disagreeable stainless steel that doesn't play well with stones and I would rather have my M2/D2/52100 at higher hardness."
I usually sharpen with the knife in my left hand and the hone in my right, and using this method I tend to get a sort of "semi-convexed" edge because I can't hold the angle very well. The edge I get isn't as pretty as the one I get on the sharpmaker, but the knives are sharp and there's a lot of metal behind the edge. Once I had learned to get rid of the burr my old Native in CPM 440V (now S60V) held a pretty good edge for a long time.