Help me solve an edge problem please

SC_Dave

SC_Dave

Joined
Jul 29, 2010
Messages
187
I have a Benchmade 585 Osborn 154 CM.

I can get it shaving sharp but the edge doesn't seem to hold. After only a few uses it looses it's edge. I would consider the uses minor not drastic. How can I correct this? Is my angle wrong?
David
 
Solution = remove wire-edge. There are many posts/threads about this problem & cures.

Chance of wire-edge go up rapidly as bevel angle goes down below 30* inclusive. 30*+ inclusive micro-bevel is one of a way to alleviate/minimize wire-edge.
 
I thought I was removing the wire edge but I guess not. So you're saying I need to sharpen using a deeper angle as apposed to shallower correct? IE raising the spine to achieve a greater angle....
David
 
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One little trick is to draw the edge through some hard wood to remove the burr. I'll do that a few times lightly when going to the next grit. 1000 grit, couple strokes though wood, 6000 grit, couple strokes through wood, then 12000 and a couple stokes trough wood. Then a thorough stropping. BAM!! Stupid sharp, happy edge
 
Likely a wire edge/burr, as suggested. Might also be some weakened steel damaged by overheating during factory grinding (if it's pretty new). Sometimes it takes a couple or three sharpenings to get rid of the weak steel at the edge. Can speed this up by lightly scrubbing the 'new' edge vertically across a stone (edge perpendicular to stone's surface, as if slicing the stone in half). Weak steel will be scrubbed off; re-bevel and/or re-sharpen after doing that.

If it's just a burr/wire, slightly elevating the angle and using some edge-leading strokes on the stone will work to gently file it off. Do this with very, very light pressure, so as not to make the burr bigger or create a new one. Check the edge every two or three passes; cut into some hardwood, cross-grain, two or three times. Then check normal cutting tasks (paper, cardboard, etc.) to see if the new edge stays durable. If it is, the cross-grain cutting in hardwood shouldn't diminish the sharpness much, if at all. If there's still a stubborn burr, sharpness will likely fall off quickly, after the hardwood cutting.


David
 
Thanks very much for the help guys. I'll work on it and see what I can figure out.
David
 
Using edge leading strokes across a stone or diamond as OWE stated above is what I prefer; follow that up with a cardboard box strop; plunge the blade through and down the side of the cardboard box, its one of the fastest techniques I know to polish an edge where the wire edge has just been removed.

It is also quite possible that the edge was overheated a little and the surface steel that makes up the edge has been left somewhat soft. A few sharpening s will improve the holding ability of the edge as this soft structure is removed. If the edge was Cooked during sharpening, send it back it will never hold an edge.
 
I think it's the knife and not the sharpening. Personally I've never been too impressed with BM's 154cm, takes a great edge but could do better at holding it.
 
Thanks to all who contributed here and in particular "The Burr" post in knifenut's signature line. I just took my sharpening to the next level. I really appreciate the help.
David
 
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