How do you sharpen a convex blade like an Opinel...... with stones.
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Is there a good way to sharpen these knives? i have a Lansky system, which I figure is pretty useless for the task, and a pair of rather expensive bench stones (soft and hard).
I distinguish between the shape of the grind (from edge to spine) and the shape of the bevel (near the cutting edge).
As I understand it, you can have a hollow grind with a convex bevel and a convex grind with a 'V' bevel and so on.
I've not cracked the code on putting a true convex
edge bevel on a knife using any technique. I use a Lansky on my Opinels to put a
faux convex bevel on by setting an aggressive back bevel at 17 degrees, a secondary bevel at 20 degrees and a final primary cutting bevel at 25 degrees. I use my knives sort of hard so I'm playing with the larger angle in hopes of extending edge life somewhat.
I find I like this faux-convex better for making wood shavings. I'm hoping that stropping somewhat softens the transitions of the bevel surfaces towards a real convex. For me, Lansky == training wheels and that's ok with me.
I don't have a strop and it seems a bit silly to spend $30 to $130 on a strop and abrasive compound for such an inexpensive knife.
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I know another common way is to use sandpaper, which seems like a quick way to ruin the blade finish.
Different answers for all of us. I've polished out Opinels to a mirror polish using wet/dry in the same way that I restored old bike parts. Opinels new have pretty crude factory grind marks on them and removing them does make them slip through wood better. In any event, I see wet/dry as a part of the solution to maintaining a mirror finish, especially if you're using above 1000 grit.
If you have access to a junk leather belt, that a piece of scrap wood and some white glue gets you your strop for cheap.
I've found that stropping blade sides (and bolsters) with green compound is a nice way to maintain high polish.
If you do wish to maintain a full convex, j
ust 'stropping' the blade at a shallow angle (flush), on some sandpaper (silicon carbide wet/dry, or aluminum oxide) over a firm or hard backing, is a very easy way to sharpen these. Anything from 320 grit and up will work well, depending on desired edge finish. And it WILL maintain some convex, done this way in a stropping fashion. The degree of convex will be more subtle on firmer backing (I like wood or glass), but it'll still be there. This is how I've maintained mine, though to higher finish at 2000+ grit; see below.
David, do you do this to
a) Maintain the blade grind
b) Maintain the cutting edge/bevel
c) Both?
I've not been able to get any knife back to hair popping using this method and it occurs to me looking at your pictures that you've kept a better blade grind than I do by just focusing on the edge bevel. I tend to oversharpen my Opinels using the Lansky (or DMT stones), get some blade loss and then I NEED to back bevel with the Lansky as I back the edge up into the thicker part of the blade.
I really should just give up on popping hair, I think. But am curious if you actually maintain the edge bevel with your technique.
(PS - I owe you more than you can know for your incredibly helpful posts. If you ever wonder if anybody out here is grateful, don't. You've really helped open up sharpening at all for me and I'm very, very much in your debt.)
