Hey guys! I've just recently gotten into collecting pocket knives, and I wanna make sure I'm taking proper care of them. My last two purchases have been karambits, both with fairly steep recurved blades, whose edges I'd like to be able to maintain.
I know that normal sharpening stones aren't going to allow me enough contact with the blade to actually put an edge on it, so I've picked up a Smith's DRET sharpener and have been practicing on an old dull knife with a stiletto blade, just to try to get some basics down. I'm getting better with it, but I'm struggling to get an even, consistent edge. Even without any special optics, I can see with my own eyes that I've got wildly uneven angles.
Granted, I'm practicing with a very low-quality knife that was already in pretty rough shape. I've managed to get the edge from "literally unable to break the skin with 20 pounds of pressure and aggressive sawing motions on my forearm" to "can cut through paper with about half of the blade before bunching up", though it's come at a cost of scratching the absolute hell out of the rest of the blade (which is just me being sloppy).
I figure that once I'm able to get competent enough with sharpening a normal blade shape that I'll move on to testing with a donor karambit. I picked up a super cheap, mall-ninja-ass karambit on Amazon because the reviews were all poor and said that the knife arrived completely dull, so I figured this would be perfect to practice sharpening. Unfortunately, it arrived with a surprisingly sharp edge, so I'm gonna have to abuse this knife for a bit before I can even practice anything on it.
Just curious what sort of tools y'all recommend for dealing with recurved blades, or any techniques I could try to incorporate into my practicing. Thanks!
I don't know about the "right" way, but what's always worked best for me on this type of thing are round sharpening rods. So I think you're on the right track with the DRET and its round profile.
As always, the key is keeping a consistent angle between the sharpening stone and the knife. Free hand sharpening with a round rod is even harder than with a flat stone. You might think about setting up some manner of angle jig. If it were me, I'd steal the idea from the Spyderco Sharpmaker: Make some manner of jig that holds the rod at a specified angle, and move the knife down along it holding it precisely vertical rather than trying to move the stone. Come to think of it, the rounded corners of the Sharpmaker's stones would probably work pretty well for that task also.
If you want to educate and/or annoy yourself, grab a cheap linen magnifier from the internet. You can easily inspect your edge geometry up close with one of those and see if you're hitting the correct angle, if you've rolled the edge, where any inconsistencies are, etc.