Holy cow!
I was pondering this a while back reading about how folks put a convex edge on their blades, and it got me to thinking. The B&D Mouse pad sander we have here has a soft pad back, maybe....
So I tried it out with another cheap knife I got my hands on. I was using some 220 grit paper, and here's the technique (intuitive) that I tried:
Turn on the sander, tip it in with your right hand till it is inverted about 30 degrees or so. Draw the knife edge from the low side on the left up to the high side on the right, rolling it a little as you draw, pulling the edge of the knife from left to right, like you would do with a regular mouse pad. I never laid the blade flat on the pad, I started about 10 degrees or so off flat and rolled to about 20. I used about 5 lbs of pressure against the pad. The first couple passes I just drew the blade straight up the pad, so the bearing surface stayed the same through the pass. Then I just started drawing the edge up like I was slicing while I pulled along the pad, so that the bearing edge moved from the hilt to the point. I did that 10 times on a side, and then checked the profile. Sure enough, that blade was convexing, and pretty evently end to end and side to side. I did another 10 passes on each side, and looked for a burr. There was none!!. The bearing edge looked pretty clean and tight, I couldn't see any cut marks on the surface with my naked eye.
I checked the sharpness, it ain't too bad. It will cut hair off my arm. I think this is a pretty soft knifeblade, though. All the blade has on it is "Pakistan" stamped down by the hilt.
The blade is not a full convex, but about a third of the way in from the cutting edge. The convex isn't totally even end to end, but it is not too bad for my first time. I don't reckon it got hot enough to change the temper. I checked the heat on the blade with my wrist once and it didn't feel more than a little warm.
Anyone else hear of this technique? Working a blade this way didn't feel awkward at all, a lot like when I strop.
I was pondering this a while back reading about how folks put a convex edge on their blades, and it got me to thinking. The B&D Mouse pad sander we have here has a soft pad back, maybe....
So I tried it out with another cheap knife I got my hands on. I was using some 220 grit paper, and here's the technique (intuitive) that I tried:
Turn on the sander, tip it in with your right hand till it is inverted about 30 degrees or so. Draw the knife edge from the low side on the left up to the high side on the right, rolling it a little as you draw, pulling the edge of the knife from left to right, like you would do with a regular mouse pad. I never laid the blade flat on the pad, I started about 10 degrees or so off flat and rolled to about 20. I used about 5 lbs of pressure against the pad. The first couple passes I just drew the blade straight up the pad, so the bearing surface stayed the same through the pass. Then I just started drawing the edge up like I was slicing while I pulled along the pad, so that the bearing edge moved from the hilt to the point. I did that 10 times on a side, and then checked the profile. Sure enough, that blade was convexing, and pretty evently end to end and side to side. I did another 10 passes on each side, and looked for a burr. There was none!!. The bearing edge looked pretty clean and tight, I couldn't see any cut marks on the surface with my naked eye.
I checked the sharpness, it ain't too bad. It will cut hair off my arm. I think this is a pretty soft knifeblade, though. All the blade has on it is "Pakistan" stamped down by the hilt.
The blade is not a full convex, but about a third of the way in from the cutting edge. The convex isn't totally even end to end, but it is not too bad for my first time. I don't reckon it got hot enough to change the temper. I checked the heat on the blade with my wrist once and it didn't feel more than a little warm.
Anyone else hear of this technique? Working a blade this way didn't feel awkward at all, a lot like when I strop.