Dull convex, great cutter?!

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PsYCHoT|K

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Mar 10, 2012
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I have a Fallkniven F1 that is pretty dull. This thing can't even cut paper. When I run my finger along the blade edge, it seems like I could put quite a bit of pressure on it without slicing myself. The thing is, that it cuts wood really well though. When I compare it to my razor sharp Mora, the dull F1 actually slices through wood better. This is confusing to me, as I see youtube videos of people with convex blades that will shave hair and slice through paper like no one's business. I especially am in awe at virtuovoice's videos most of the time. I spent about 15 minutes stropping the F1 with black compound, but it is still pretty dull. I also have a brand new Bark River Bravo 1 that actually came not as sharp as I had expected. It does cut paper okay, but will not shave hair at all. I guess my question is, do I need to haul out the sandpaper to attempt to sharpen my F1? Or just give it a few hundred passes on the black compound strop? Any suggestions or recommendations would be greatly appreciated. I am not a complete amateur when it comes to knives, but I could still see myself messing up the knife with sandpaper by using too steep or too shallow of a stropping angle or something. Thank you in advance for your help, and for not insulting my ignorance! I am trying to learn, and have a long way to go when it comes to knife maintenance and sharpening, especially convex edges.
 
My understanding is that's an advantage of convex edges. May not feel sharp in the traditional sense but can still cut really well.
 
Strop on sandpaper mounted on something that "gives" like a mouse pad or a phone book. Do a little on medium, then move up to fine, then strop on your loaded leather. It should be sharp as hell when you're done and it will cut EVERYTHING better! Even wood!
 
If it's not cutting fingers or paper, but is cutting wood, I'm betting the wood is pretty softish? Cutting with the grain, or across it? How polished is the convex on it?

The lack of cutting of fingers or paper suggests the apex might be over-polished & rounded, if only very slightly. Stropping with some black compounds on leather or other relatively conformable backing can do this (I have some 1-3µ black 'emery' compound that behaves similarly). The edge really only needs to be relatively thin in cross-section, without needing a perfectly crisp apex, in order to cut most woods reasonably well; paper-slicing and finger-'biting' will need a crisper apex.


David
 
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Thank you all for your help and for your suggestions. I am thinking I might just need to try out the 2000 grit sandpaper on the mousepad. David, it is very strange to me that this super dull knife can make feather sticks incredibly well... on all types of wood. I am, however, usually going with the grain, so I'm sure that helps. If I had managed to over-round the apex a couple of years ago when I didn't have much experience stropping, what is the best way to repair this? Sandpaper and mousepad? Thank you again for all of your suggestions, it really is helpful.
 
*Update*: Wow. Thank you for your help guys. I just used the 2000 grit and mousepad. I only made about 5 passes on each side, and WOW what a difference. I am going to strop it with the black and then green, and I do believe I have a knife again that does not imitate a butter-knife! Thanks again for the help everyone!
 
PsYCHoT|K said:
Thank you all for your help and for your suggestions. I am thinking I might just need to try out the 2000 grit sandpaper on the mousepad. David, it is very strange to me that this super dull knife can make feather sticks incredibly well... on all types of wood. I am, however, usually going with the grain, so I'm sure that helps. If I had managed to over-round the apex a couple of years ago when I didn't have much experience stropping, what is the best way to repair this? Sandpaper and mousepad? Thank you again for all of your suggestions, it really is helpful.
Click to expand...

To get the edge crisp again, I'd use the sandpaper over a hard backing, like wood or glass/stone, etc. The mousepad is relatively soft, and will contribute to additional rounding of the edge, if pressure is too heavy. Using the paper over a harder backing will tolerate some more pressure without that risk. Still want to keep pressure as light as possible (to minimize burring), but it'll be more forgiving if you do get a bit heavy. Same technique still applies, using trailing strokes (stropping motion) on the sandpaper.

Edit:
I see in your latest post, you've already got it tuned up. Good work! :thumbup:


David
 
Thanks again David. Yes, the mouse pad was very soft and I was a bit worried about rounding the edge even more. I did it as if I were sharpening an egg shell, and it seemed to work. I am now positive I rounded the edge a couple of years ago by putting too much pressure on the strop with the knife. Gotta love learning, especially when others are willing to help!
 
Had the exact same problem but I had to put my paper on a hard wood surface because I was rolling the edge too much. Now it shaves pretty damn well. :thumbup:
 
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