Ok... My brain got left at the office this week. Anybody else have a job that does that?
I'm ready, I think, to talk about the how. But only in small doses.
I'm trying to get my head around the different approaches to sharpening and maintaining, but in terms of what they do to the apex and how much material they remove. All of these as ways to reach a convex apex and thin convex blade.
I bolded the above part, only to emphasize one thing: I wouldn't even focus on a convex
apex, per se. It always seems to me, that if one is too intent on convexing the apex, it almost always ends up with a rounded (therefore blunt) apex. Instead, focus on smoothly and subtly convexing the
shoulders of the edge grind, and the rest essentially takes care of itself. I'm thinking you may have already understood this distinction, as the terminology of 'convexing the edge' sometimes is used to describe a process that actually convexes the shoulders of the edge, and doesn't necessarily imply actually convexing or rounding the apex itself. But, to be safe, I just wanted to make sure, for clarity.
And with Opinels in particular, the blade grind from the start is already a gentle convex, so focusing on deliberately convexing it more may not be necessary anyway, if one of the edge-trailing methods is employed on a somewhat softish or conformable backing. If done as such, any further convexing essentially takes care of itself.
Am I right to think of the different approaches as being on scale in terms of how much material they will remove? Would love feedback, especially on the relative scoring on a 10 - 1 scale.
10: Edge leading on stones raising to a burr, progressing through stones as edge damage dictates.
6: Edge trailing on stones, keep edge angle low, not raising to a burr
With the Opinels, I wouldn't even consider the above^^ (personal preference). Starting with wet/dry on a firm backing (wood, or thin leather or paper over wood, for example) with 220/320-grit is as aggressive as I'd ever want, for re-shaping or thinning the grind on the already thin-bladed Opinels.
4: Edge trailing on wet/dry with wood backing, not raising to a burr
1: Edge trailing on a loaded strop
If this is true, can somebody describe the pros/cons of edge trailing on a stone vs edge trailing on wet/dry with wood backing?
(Heavy handed, I've been watching the videos. Interesting stuff.)
Part of the reason I earlier mentioned avoiding the stones (at least for now) is, I've had a much easier time minimizing burrs when using a backing that's not
quite as hard. Not to say that you can't or even shouldn't use them. But when first trying to figure out the edge-trailing method, I believe in minimizing other distractions that can get in the way. I firmly believe that focused pressure is what creates/exacerbates burrs, and a harder backing (stone) will act to do just that. BUT, as one starts to get comfortable with regulating and using pressure to advantage, that's a good time to start migrating back to using a firmer backing, at very light pressure, to refine the apex with minimal rounding. I think anyone who's read many of my posts already knows that I advocate going as firm as possible with the backing/substrate, but that's somewhat dependent on already being comfortable with regulating pressure.
And again, with the Opinels specifically, these blades are already pretty thin. Coarse & hard stones will remove metal very quickly, and I tend to believe that sort of aggressiveness isn't really needed for blades like these anyway. I prefer them for hogging off lots of metal from bigger and thicker blades, especially in more wear-resistant steels, but neither really applies, in this case.
Additionally, in regard to your last two mentioned options (#4 and #1, in your scale for metal removal), there's a WIDE range of options even between those two. For example, very gradual reductions in the hardness of wood will make noticeable differences in aggressiveness. Think of going from something like oak/maple (harder, more aggressive) down through pine, then basswood, then balsa (softest wood, least aggressive). Taken even further in scope, you could also add/subtract layers of paper in between the wood and the sandpaper, to further fine-tune the aggressiveness, and also the degree of convex that will result. And as if that's not enough, also consider using some temporary adhesive to firmly stick the wet/dry to the wood backing. That'll make it work more aggressively in itself, with the other factors remaining unchanged. These are the things I spend a great deal of time experimenting with, and I've learned a ton from it.
David
