De-polishing an edge

tempey

tempey

Joined
Jan 23, 2009
Messages
352
I recently got a Spartan Enyo and it is a great little knife. It came with a very polished edge to the point where it slips on things and won't catch whatever I am trying to cut. I was wondering if anyone knew of a way that I could roughen up the edge for lack of a better word to make it actually cut things but still be sharp.

Any advice would help, Thank You
 
To me it sounds like the edge is dull if it is just sliding over the material.

What are you trying to cut?

If you run it against your fingernail does it just glide over it or does it catch immediately?
 
If it's slipping during cuts, sounds like the manufacturer didn't quite finish the edge before polishing the bevel.

As mentioned, the quickest way to put some bite back in the edge would be to give it a few passes on a coarser grit, at a slightly elevated angle (as with a microbevel). It could also be completely re-bevelled, and finished to whatever grit you wish. So long as the edge gets fully apexed, it should be sharp at any level of finish.
 
Thanks for the input guys. Its weird it slides right off paper sometimes like an extremely dull knife but when it does cut the paper it is an extremely clean cut. Would putting it to a ceramic rod for a few strokes work? Or do you think I need to use stones?
 
Sounds like it was polished too much and rounded over the apex. A ceramic will likely not do very well, knowing the edge was not cared for in the sharpening process usually means the bevel as a whole needs adjustment.

When a bevel has been over polished and rounded its in the same condition as a well used and dull knife. It will take similar amounts of sharpening effort to restore correctly.
 
a highly polished edge will slip and is why i never go above 400 grit. you need to check and see if the edge needs redone or just roughed up. look straight down on top of the edge in good light and see if you can see a shine which is a burr (look at a butter knife edge up). if you see the edge shine you need to work up a burr to get the knife sharp. what do you have to sharpen with?
 
I had a William Henry come the same way- it would shave but not cut. I sent it back (for other issues) and asked them to resharpen it while they had it and it came back the same way. I just went over it lightly with a ceramic and it came out fine. As always, YMMV.
 
tempey said:
Thanks for the input guys. Its weird it slides right off paper sometimes like an extremely dull knife but when it does cut the paper it is an extremely clean cut. Would putting it to a ceramic rod for a few strokes work? Or do you think I need to use stones?
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That sounds like the apex is not complete along the full length of the edge, OR there's a wire edge. Either way, the best way to figure it out, is to see it close up. Take a look at the edge under magnification, and very bright light. When looking directly at the edge under bright light, 'dull', bent, folded or dinged portions of the edge will reflect more light, and the really sharp portions should almost 'disappear' under that light. To help figure out where to look for each, do your paper-cutting test again, very SLOWLY. Use a draw cut (slicing cut), starting at the heel and slicing along the full length of the edge, to the tip. Pay VERY close attention to where it cuts well, and where it slips. Might even mark specific spots on the blade with a Sharpie or other black marker, where the cutting is poor (or where it's very good). Then take a close look at those areas under magnification. A simply 'dull' edge will appear rounded or otherwise 'blunt', and the wire edges will appear very thin & bent/folded to one side or the other. A truly sharp, clean edge should always look like a crisp 'V' with virtually no reflected light from the apex.
 
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To me it sounds like the edge bevel is too obtuse. While a polished edge will skate on some materials, its my experience that if its skating on paper the bevel is probably too wide. It'll do poorly on some materials while still shaving hair no problem. A coarser edge will work better at wider bevel angles - IMHO either rough it up or check the bevel and see if it couldn't stand to be reduced. A quick way to do this is to put the edge fairly flat on some card stock or piece of stiff leather (even an old belt will do) and as you push the edge along slowly raise the spine. The point where it starts to catch is pretty close to the edge apex.
 
I have a a couple diffeerent sharpeners to work with. I tried to see if there was a burr or wire edge or anything but I couldn't detect any. I will try the ceramic rod and if that doesn't work I will just reset the entire edge on my Edge Pro. Thanks for all the help guys, if I remember I will let you know how it comes out.
 
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