Over the years it has seemed that certain hones (and honing combinations)work better for a particular blade than others. Since the heat treatment process can change the carbide structure of the blades I don't just attribute these particularities to the alloy. There are also lots of blade geometry issues that influence optimum sharpeness as well.
For example I got a Buck Master Series model 501 folder last week. It has a fairly thin 2-5/8" blade of BG42 alloy. One of the reasons I got it was to see if I could make it shave like a straight razor (no it's not practical, but it's a thing I do). I put it through my basic sharpening sequence: thin edge using medium course diamond hone, smooth the thinned bevel using extra-fine diamond hone (gee that feels real sharp), refine the edge using extra fine ceramic rods, strop on hard leather with chromium oxide buffing compound. The result shaved well, but wasn't really where I wanted it.
I took the knife to work with me on Sunday. I was bugged that I couldn't get a clean shave of my two-day old beard stubble (it shaved, but left some stubble behind). I thought back how sharp the edge felt before I used the ceramic rods and strop. I thought maybe the edge would shave better with a slight bit of toothiness, and maybe even a touch of wire edge. I tried stropping the edge using a Norton india stone I keep in my office desk. It didn't seem better, probably worse. I tried a little honing and stropping with a small Blackjack Knives hone from my desk, it seemed even worse. I tried stropping on various surfaces available in my office--no joy. (Note to self, get razor strop for office). It ruined my day.
Last night I thought of an alternate path. Return to the medium then extra fine diamond plates. Then use my 1000 and 4000 grit Japanese water stones. Refine the edge with a little work on freshly cleaned ceramic rods. Then strop on a relatively non abrasive plain leather razor strop. This worked much better.
What did I learn? It seemed that the BG42 liked really clean and sharp honing particles and then a non abrasive stropping. I've had other knives that really love the Norton India stones, but it just isn't universal. Way back when it seemed like the basic carbon steels liked an oily India Stone followed by stropping on leather with red iron oxide buffing compound. They seemed to get more of a razor edge that way.
I like Cliff's explanation of how the sharpening with diamond cleans up the carbides. I suspect that some of the clean up is actually ripping out some carbides and exposing fresh ones. I don't think that diamond is absolutely necessary for the harder steels, but I would want a hone that is not 'loaded' with metal or glazed from use (got the edges worn off the abrasive particles). The Japanese water stones have an advantage of shedding their worn abrasive particles to expose sharp-faced particles. I try and keep my ceramic rods clean by scouring them with sink cleanser.
It's good to try different sharpening procedures and tools on different knives. Sometimes you just have to experiment if you really want the ultimate performance. Of course any sane person would have been happy with the edge I got off the extra-fine diamond plate.
[This message has been edited by Jeff Clark (edited 12 October 1999).]
I'll put it to the test...let you know later.
