As you can see from the thread title, I sharpened some CPM 20CV today. The knife is a Benchmade Foray, a medium-heavy weight folder with a recurved blade.
The Benchmade factory edge was very sharp out of the box, and it was holding up to light use very well. It could have gone a while without any sharpening, but I couldn't wait. You see, I have reached a point in my life where I would rather sharpen than cut. I recognize that this is not normal, yet I refuse to seek help.
The recurve presented a problem. I've got various stones and other tools that I would have loved to use, but getting into the hollow part was going to require something different. I settled on a Lansky Master's Edge, a crock stick type device with two sets of narrow ceramic rods. I used the Lansky instead of my ancient Spyderco Sharpmaker because the Lansky offers 25, 20, and 17 degrees/side angles, and I wanted to set the beefy Foray blade at 17. Not a practical choice for a work knife, but sharpening a sharp knife is not very practical, either. And besides, this knife rarely does anything more challenging than opening a box or slitting an envelope.
It is truly all about the sharpening, for me. I am upside down.
The narrow little dark ceramic rods didn't exactly inspire a lot of confidence, but I didn't see any alternative, so I inked up the bevels and took a few strokes. I think the guy on the belt at Benchmade might have been a little off, as the rods were hitting the apex on one side, and the shoulder on the other! (It could have been the Lansky base, but an angle block confirmed that the Lansky was set up right, so who knows?) There was going to have to be some steel removed to get this one re-set to 17. No matter. This is the life I have chosen for myself.
Fast forward 30 minutes or so. It wasn't easy, but I didn't expect it to be. Frankly, it wasn't nearly as bad as I had been warned it would be. The steel came off slowly but it came off where I wanted, and after what seemed like a few hundred strokes, I had clean, even bevels on both sides, from heel to tip.
I switched to the white stones, and the steel seemed to react very well to only twenty or so medium-to-light strokes. It showed a fine, very uniform scratch pattern, maybe 1,000 or 1,200 grit.
It cut heavy cardboard with authority. Arm hair popped reliably and easily, receipt paper sliced up very neatly and cleanly. Cigarette paper was more challenging, but I use Zig-Zag Cut Corners, which is probably lighter than other cigarette papers, and my technique needs work, so I was not discouraged. It should be noted that the Foray blade is pretty thick for this kind of test.
Overall, the CPM 20CV was harder to sharpen than most other steels I've sharpened, but I would not describe it as challenging. It took a while, but the process went smoothly with no glitches, and the tool I used was a consumer-grade crock device that retails for about $60. I think much of what I had read about about how hard it was going to be was largely overstated. If not for the recurved blade, I have the feeling that my diamond stones or Shapton Glass Stones would have made short work of the job.
Good steel! I don't mind spending a few more minutes sharpening the blade when it has such outstanding edge retention and corrosion resistance. Good stuff!
Likewise for the Lansky Master's Edge device. I don't even remember why I bought this thing, as I lean toward fine natural stones or more cutting edge diamond or ceramic bench stones, but for $60 this little guy really delivered, re-setting the edge on a sizable piece of super steel.
The holes that the rods fit into are lot more sloppy than I would like, so I'm thinking of fabricating another base out of one of the tropical hardwoods, with tighter holes to keep the rods from bouncing around. I'm kind of surprised there is no high-end alternative to this design, as it works well enough even with the sloppy tolerances. If I can build a better base, I'll post another thread.
The Benchmade factory edge was very sharp out of the box, and it was holding up to light use very well. It could have gone a while without any sharpening, but I couldn't wait. You see, I have reached a point in my life where I would rather sharpen than cut. I recognize that this is not normal, yet I refuse to seek help.
The recurve presented a problem. I've got various stones and other tools that I would have loved to use, but getting into the hollow part was going to require something different. I settled on a Lansky Master's Edge, a crock stick type device with two sets of narrow ceramic rods. I used the Lansky instead of my ancient Spyderco Sharpmaker because the Lansky offers 25, 20, and 17 degrees/side angles, and I wanted to set the beefy Foray blade at 17. Not a practical choice for a work knife, but sharpening a sharp knife is not very practical, either. And besides, this knife rarely does anything more challenging than opening a box or slitting an envelope.
It is truly all about the sharpening, for me. I am upside down.
The narrow little dark ceramic rods didn't exactly inspire a lot of confidence, but I didn't see any alternative, so I inked up the bevels and took a few strokes. I think the guy on the belt at Benchmade might have been a little off, as the rods were hitting the apex on one side, and the shoulder on the other! (It could have been the Lansky base, but an angle block confirmed that the Lansky was set up right, so who knows?) There was going to have to be some steel removed to get this one re-set to 17. No matter. This is the life I have chosen for myself.
Fast forward 30 minutes or so. It wasn't easy, but I didn't expect it to be. Frankly, it wasn't nearly as bad as I had been warned it would be. The steel came off slowly but it came off where I wanted, and after what seemed like a few hundred strokes, I had clean, even bevels on both sides, from heel to tip.
I switched to the white stones, and the steel seemed to react very well to only twenty or so medium-to-light strokes. It showed a fine, very uniform scratch pattern, maybe 1,000 or 1,200 grit.
It cut heavy cardboard with authority. Arm hair popped reliably and easily, receipt paper sliced up very neatly and cleanly. Cigarette paper was more challenging, but I use Zig-Zag Cut Corners, which is probably lighter than other cigarette papers, and my technique needs work, so I was not discouraged. It should be noted that the Foray blade is pretty thick for this kind of test.
Overall, the CPM 20CV was harder to sharpen than most other steels I've sharpened, but I would not describe it as challenging. It took a while, but the process went smoothly with no glitches, and the tool I used was a consumer-grade crock device that retails for about $60. I think much of what I had read about about how hard it was going to be was largely overstated. If not for the recurved blade, I have the feeling that my diamond stones or Shapton Glass Stones would have made short work of the job.
Good steel! I don't mind spending a few more minutes sharpening the blade when it has such outstanding edge retention and corrosion resistance. Good stuff!
Likewise for the Lansky Master's Edge device. I don't even remember why I bought this thing, as I lean toward fine natural stones or more cutting edge diamond or ceramic bench stones, but for $60 this little guy really delivered, re-setting the edge on a sizable piece of super steel.
The holes that the rods fit into are lot more sloppy than I would like, so I'm thinking of fabricating another base out of one of the tropical hardwoods, with tighter holes to keep the rods from bouncing around. I'm kind of surprised there is no high-end alternative to this design, as it works well enough even with the sloppy tolerances. If I can build a better base, I'll post another thread.
