Kershaw Bump Reprofiling Headahce

R

rottwang

Joined
Feb 5, 2006
Messages
310
I took my Kershaw Speed Bump with (Sandvik steel) to the local cutlery shop for reprofiling. I wanted the knife taken down to 10° on each side, which all things considered was unreasonably optimistic stupid me.

The shop (which shall remain nameless for the time being) started, but then kind of gave up and mauled the blade with the most maddeningly inconsistent grind i've seen. the tip came back rounded and basically i felt that the blade was deformed and less sharp then when i brought it in. The guy apologized, did a nice job buffing out his earlier mistakes and kind of put a ~18° grind on one side, then gave up on the other side. I decided to cut my losses and (not bring any more pocket knives to this place, only kitchen knives)

Recently purchased a Lansky 5 hone (non-diamond) system and figured i'd give it a shot myself, nothing left to lose.

I have to say reprofiling the blade to 20° on each side was relatively easy although doing the reverse side of the 'bump' required taking off a fair amount of steel. On my first try it's close to the original factory sharpness so i'm quitting before i start really ruining the knife. on the up side i am no longer afraid to sharpen knives with a lot of recurve to them! :eek:

Here's the photographic evidence of my damage:

IMG_0096.jpg
 
Find somebody that has an eze-sharp, and uses the round rod adapter with diamond and/or ceramic round stones.
 
Excellent piece of equipment by the way. It comes with the little piece you will need to make it work with a rod or flat file. I have the flip version. If you get one, be careful when you set up the flip as it's easy to set it up wrong and get different bevels on different sides of the blade, but if you set it up correctly and carefully, there are no problems. This thing is beefy also, well worth the price IMHO. I use spyderco ceramic stones with the stone holders on mine also.
 
unfortunately i just invested in three sharpening 'kits' the lansky 5 stone, lansky ceramic and spyderco sharpmaker (these two are in the mail) so .. i'm kind of out of cash. i realize now i should have done a little more research and gotten a more comprehensive setup, but at least the kits are highly portable :( just surprised that the recurve of the Bump isn't unmanageable
 
Of those three, I think you will have the best luck with the sharpmaker on that blade profile. I would recommend spending an hour or so sharpening other knives with it before you tackle the "bump". When you do go at the bump with the sharpmaker, make sure you take the time to alter your stroke so as to keep the knife edge as perpendicular as possible to the ceramics, and remember patience as those ceramics don't take off very much metal so you will be at it for awhile the first time. I have the diamond rods for my sharpmaker, and they helped speed things up quite a bit, but still take awhile.

If you do a search, there are many, many threads and methods for sharpening. Jigs such as the edge pro and eze sharp are probably the easiest to use (along with the convex sandpaper/mousepad system). To be completely honest with you, the sharpening headaches associated with blade designs like the bump tend to keep me away from that blade design even though it can be a superior cutter. More moderate recurves are easier to sharpen ie outcast, retribution, etc. All this is, of course, just my opinion based on my personal experiences tempered with what I have read/heard/seen from others.
 
Anything with a flat surface is going to have trouble with a normal gentle recurve, much less the aggressive one on the Bump.

The best solutions involve anything curved or with a corner.

I used a DMT diamond stick with 3 surfaces hobbled together with the Lansky L-frame for my severe hawkbills and recurves, but I finally just gave up and got sick of recurves and hawkbills. Don't buy them anymore.

The EdgePro, stock, will not handle this type of recurve that well, from experience. However, for a while, Ben was selling blank inserts that you could epoxy a Spyderco triangle stick to, which from most reports, works pretty well, if rather slow.

-j
 
i am cursed with liking knives with extreme recurve like the Kershaw Bump, Elschwitz Pharoah or Spyderco Captain..
 
id drill a hole into a lump of wood at the bevel angle you want and stick a length of dowel in it so its like a sharpmaker rod stickin up.
try wrapping different grit wet and dry sandpaper around the dowel that would ride inside your curves.
id be trying something around 20mm dia or bigger, just to work around your internal curves. external curves would be fine with the flat sharpmaker rods im thinkin.
 
You must log in or register to reply here.
Back
Top