Blade will not perform

F

FLYBYU44

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Jul 8, 2006
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I currently EDC a Kershaw MiniCyclone http://www.kershawknives.com/productdetails.php?id=34
I'm having a problem with the blade. I have the blade very sharp, it will shave hairs off my arm, however it doesn't seem to cut anything else very well. Such as I can barely open an letter with it, clamshell plastic packaging seems to elude it's razor edge as well, this has me very confused. Before this knife I had a Kershaw Leek and it cut everything with ease. Is is the steel? My Leek had different steel as it was an older model. Or is it the shape of the blade that makes it kind of "roll" off things? I've actually been thinking of replacing it with something else, problem is I like the knife and don't really want to get rid of it, it just won't cut anything.
 
First thing that comes to mind is edge geometry. How heavy of an angle is the edge bevel at?
 
I'd also check the edge geometry as well. Also, how polished is your bevel? Highly polished edges can have problems cutting things like plastic (i.e. clamshells)
 
It could also have a burr, which would shave your arm hairs, but flop over and distort when trying to do real cutting.
 
A polished edge will shave and it will push cut through food, but for regular daily use, you should have a coarser edge. If you're using ceramics, stop at the medium grit, don't use the fine, and you will have a microserrated edge that will bite into tough materials as it cuts.
 
It shaves the hair off your arms, but it cannot cut an envelope?

I don't think that's possible.:confused:
 
It cuts envelopes open but with some difficulty, it should whistle right through them. I'm not too up on edge geometry and all that so I don't know what angle it is at. The edge is the factory angle that was on it when I got it. I occasionally touch it up with a ceramic rod, much in the same fashion that someone would sharpen a kitchen knife with a steel, I have a steel too, but find that the ceramic leaves a much better edge. It doesn't seem to have a overly polished edge on it, I've always sharpened all my knives in the same manner and never had a problem with any of the others, could be the steel of this knife, it is supposed to be that Sandvik steel, but I've only heard good things about it so far.
 
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Sounds to me that the blade is just too thick, just behind the edge.
 
Thats what I would bet. My nice thin s30v Native cuts all types of things great, but I just noticed that it no long shaves. Again. This is the 2nd time I've had to bring the shaving edge back since I bought it in Jan... S30V is starting to lose a fan, although I stave off judgement until I start using the knife in a harder environment (maybe it holds a decent edge forever but looses the razor edge quick?)...
 
Letters and clamshell packaging challenge different aspects of a blade's geometry. To do a nice job on letters requires that the edge be honed cleanly up to the edge apex at a reasonably low angle. A burred edge could do a reasonable job of this. If you can shave with an edge it should do pretty well on letters. Try lowering your honing angle (making the edge angle smaller) and do a bit more honing. Paint the side of your edge with a black marker and make sure that your honing procedes all the way to the apex of the edge.

The clamshell packaging needs much the same type of edge, but it is much more sensitive to blade overall dimensions. For that material a thin, narrow blade with a thin point is best. The thin and narrow point pierces the packaging easier. Subsequently a thin and narrow blade pushes through the material easier. The toughness of the plastic tends to pinch the sides of the blade to resist cutting and turning your cut. Your new knife is not as well shaped for clamshells.
 
Shaving is not well defined. I have seen some people say a blade can shave because you can scrape some hair at a lot of force, that won't open an envelope well. Paper doesn't require much in the way of gemetry as it isn't that binding, I would assume your edge is rolled. Recut it to a sensible angle (for general reasons) about 10-15 and then sharpen at 15-20 and wonders will happen.

-Cliff
 
Thanks for the tips guys. The blade is kind of thick just behind the edge, that may be the problem. I have been trying to get a better edge on it for a while.
 
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