Convex edge experimentation

[daverave999]

I've been playing with an old Delica that I've modded in a few ways, stropping it against some coarse wet and dry paper to try and achieve a convex edge. Does anyone have any thoughts on this?

I've been resting the W&D on my thigh and just stropping as I would if it wasn't there. Would I be better off doing it against something firmer? How hard should I press? What angle should I use?

I ask, as my results haven't been as good as I'd hoped. Or is there the possibility that the cheap and nasty W&D I'm using is just rubbish?

Anyone else 'strop on W&D' for a convex edge?

 

[me2]

I did it to a CRKT Peck folder, so I ended up with a chisel ground convex edge. I used w/d paper on a board w/ leather glued to it. I raised the blade until I could feel the flat of the primary grind on the leather, then stropped and rolled the knife away from me, raising the spine to make the convex curve. I worked fairly quickly and was very sharp. I stopped at 320 or 400 grit and then removed the bur with a sharpmaker fine rod. You could try the other method I used, which is clamp a strip of the paper to something, then stretch it out tight by hand and use it like a strop, although I did sharpen going edge in and edge trailing and didnt have much trouble till I got to the finer papers, 600 grit and up. This will also work with sanding belts hooked over something solid. I used 2 c clamps for that, one small to loop the belt through, the other large to use as a handle. Enjoy. Be warned that the slack sanding methods required removal of thumb studs to get the low angle I wanted, since the paper sags and raises the angle when you apply pressure. You can also scratch the crap out of the primary grind, but if you're fully convexing it, then that doesnt matter.

 

[Cliff Stamp]

Would I be better off doing it against something firmer?

The grind which is optimal will depend on what you are doing with the knife, assuming you want it for just light cutting then recut the primary with a full flat grind from the spine to the edge and then raise the angle at the very edge edge (0.005-0.015") to between 10-15 degrees. That ranges covers from fairly fragile to extremely durable, i.e., one is hard to damage and the other one hard not too unless you really restrict the uses of the knife. Reworking the knife to that amount will likely take about an hour even on really coarse sandpaper.

-Cliff

 

[hlee]

I did effectively this with a SAK and cheap wet/dry automotive sandpaper bought at walmart. I used a piece of leather as a backing to the paper and stropped on my kitchen table. I colored the edge with a sharpie and laid the blade flat on the paper and stropped until the sharpie mark was removed. I started with 400 grit, then went to 800 grit, and finished with 1500 grit paper and this knife will split free-standing hairs now.

 

[Ben Dover]

I reprofiled my CS SRK to convex using 400 and 1500 grit paper wrapped around a mousepad. Then stropped on a leather strop loaded with CrO, until it would push cut newsprint.

I now use a thick piece of leather instead of a mousepad.

 

[LJK]

I reprofiled my Delica 4 starting with 80 grit 3M wetordry on a mouse pad, then 180, 400, finishing with 600. Even starting with 80 grit it took a long time. For me it was worth the work I believe it slices better, but mostly I just like the way it looks.