Having a toughtiem sharpening blade on leatherman juice

thaeffman

thaeffman

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Mar 8, 2011
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I decided I would sharpen the blade on my leatherman juice, Ive had it for a few months and haven't sharpened it since I got it so its rather dull at the moment. It seems whatever I do I cant sharpen it on the sharp maker. I hit the edge with a sharpie and start with he mediums rods at 40 degrees inclusive. Its removing the sharpie so I know I'm hitting the edge, I put a burr on one side, then the other and then I alternate using lighter and lighter strokes to get rid of the burr but whatever I do it refuses slice paper. Ive managed to put a shaving sharp edge on every knife I have owned using the sharp maker but I cant even get past the medium rods on the leatherman. What am I missing here :confused:

Also sorry for the thread title need some coffee :P
 
Take a very close look at the edge with a good magnifier (5X - 10X) and very bright light. By the naked eye, oftentimes it seems like the Sharpie ink is removed, but often there will be a hair-thin 'stripe' of it along the edge, where the rods aren't touching it.

The other (slighter) possibility might be that the edge is apexed, but a wire edge/burr has folded over to one side or the other. Usually though, if the edge has been apexed enough to produce a burr/wire, at least some of the edge will still slice paper. You'll be able to initiate a cut, but the paper will snag on the burrs/wires. If none of the edge is slicing the paper, and it's just sliding over without initiating a cut, then I'd bet the edge hasn't been fully apexed.

Whatever the cause, it's very important to closely inspect the edge under magnification and bright light. When looking sufficiently close at it, it should become obvious whether it's a rounded/blunt/incompletely apexed edge, or if there's a burr or wire. With more practice and experience, these things become easier to figure out by observing cutting performance or by what you can see or feel on the edge. But that's almost impossible to do early on, by the naked eye or by touch, when one is still learning what to 'look' or 'feel' for.
 
Your missing a coarse stone, the medium rods are ok for minor dulling but too slow for a knife that has not been sharpened in a while.
 
In addition to David's & Jason's (Knifenut) suggestions, here is my 2cents.

thaeffman said:
I put a burr on one side, then the other and then I alternate using lighter and lighter strokes to get rid of the burr but whatever I do it refuses slice paper.
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This blade steel probably has large-grain and high-toughness (most likely be a low hrc HT) so the thin edge instead get abraded, it flexes away from the abrasives (as David's suspected). Something to try:

1) scrape on wood/balsa/cardboard to bent burr over on 1side (or opposite from the side you just deburred).
2) use light pressure sharpmaker strokes (edge leading) to remove rolled/bent-burr, repeat 1) until slice newsprint smoothly. Normally, it takes 1 to 3 repeat to get a clean apex.
 
The steel is 420HC, per product specs. I don't think grain size is much of a factor, or enough to be significant anyway. Should sharpen up like a Case or Buck (both 420HC also), which means burrs/wires are pretty much a certainty with this steel type, IF the edge has been fully apexed. How quickly they will be removed depends on how hard they went with heat-treat. Fairly easy at RC 57+ (such as with Buck), or more ductile and stubborn at lower hardness (such as with Case).

I still think most of the issue is with the edge not yet being apexed. The mention of going a long while, before touching up, would explain the extra difficulty in trying to re-sharpen with the relatively unaggressive Sharpmaker rods. As knifenut suggested, a coarser hone to start is likely a good idea. Something along the lines of a medium or fine diamond hone would make quick work of it. OR, a piece of medium-grit wet/dry sandpaper (around ~400 grit) laid alongside the SM rods would also work. The edge grinds on the Leatherman blades are pretty thin, so it shouldn't take long to establish a new bevel.
 
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I agree 50% :), if burrs showed up, that mean at least/minimum the grinding is apexed on 1 side.
 
The other possibility, if a burr was produced and then reduced with subsequent lighter passes, is the edge is becoming rounded over on the later passes. This is easy to do on the Sharpmaker, if the angle isn't maintained very, very steady. Again, this is something that could (should) be seen under well-lit magnification, if it's rounding off.
 
Obsessed with Edges said:
The other possibility, if a burr was produced and then reduced with subsequent lighter passes, is the edge is becoming rounded over on the later passes. This is easy to do on the Sharpmaker, if the angle isn't maintained very, very steady. Again, this is something that could (should) be seen under well-lit magnification, if it's rounding off.
Click to expand...
:thumbup: very likely in this case.
 
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