Trouble with Ken Onion Ripple EDC Sharpening

[Sintygypsy]

Last year, I was walking through Walmarts hunting isle and noticed a price drop on some pocket knives. The Ken Onion CRKT ripple was on sale for $14.99 so I jumped ont he purchase and walked away happy.

Ever since then, i've had a bloodly nightmare ( figuratively ) attemping to sharpen the knife. I can get it to working sharpness for box opening, which is what its primary use is. But, I've never once been able to hone a razor sharp edge that can shave hairs. This is odd for me because I am pretty decent at sharpening knives on my wet stones and I've also a vast array of budget to mid tier diamond and similar sharpeners, hell I've even got the Buckner chip sharpener ( looks kinda like a poker chip with a small sharpening stone on it ) Anyway, I've not a clue what I am doing wrong if I have similar blades with the same steel and same degree on the blade which sharpen to a razors edge with minimal effort on my stones and after stroping. However, this darn Ripple refuses to keep an edge for long and has never once re-obtained the level of sharpness it came out of the box with, which was medicore at best.

I've given this knife to a hardware specialist who is an expert with metal working and he said he was unable to get the knife sharp on his own hand held gear, he was baffled. He was able to get it razor sharp with an automatic grinding belt. Has anyone else encounted this odd problem before? Does this knife just stink, or can it really be this hard to get razor sharp?

 

[jinmo]

I have this same knife & have never had problems with it. It always sharpens easily and holds well. Could it be a quality control issue?

 

[bpeezer]

Mine came with a relatively obtuse edge, and it was very thick behind the edge. I had to remove a good chunk of material to get the bevel down to a reasonable angle, but after doing that the edge is fairly sharp. Sorry for picture quality, I have dropped my cell phone directly on the camera lens a few times

 

[Obsessed with Edges]

If I were betting, I'd first suspect a wide/thick factory edge angle. That's real common, especially among mass-produced and less-expensive knives in cheap stainless steel. Combine a wide/thick edge with steel that may be somewhat soft (again, common with cheaper knives), and the apparently 'sharp' factory edge may just be essentially a burr sitting atop edge geometry that's too thick to cut well. The 'sharp' burr folds over quickly, and cutting performance drops off a cliff. If attempting to 'fix' it by re-sharpening to the same factory edge angle, and following by stropping off the 'sharp' burr, not much may result in improvement.

First thing I'd do, is re-bevel to 30° inclusive or lower (make sure of the angle). At this angle, the edge geometry should always cut well, assuming the steel itself is decent (grain size fine enough, and heat-treat good enough). Bad steel or bad heat treat can't hide anymore, if the variable of the wide edge angle is first eliminated. At the very least, cutting performance should improve in the short term, leaving only the durability of the edge (steel, heat treat) in question; using the knife for a while will determine if the steel quality and/or heat-treat is good enough to keep it durable.

(BTW, posting a clear close-up of the edge on your knife can provide some very quick insight as to whether the edge angle is a little too thick; it's often pretty easy to see, based on the width of the bevels and a good look at the blade grind.)


David

 

[Fish30114]

Mine came with a relatively obtuse edge, and it was very thick behind the edge. I had to remove a good chunk of material to get the bevel down to a reasonable angle, but after doing that the edge is fairly sharp. Sorry for picture quality, I have dropped my cell phone directly on the camera lens a few times

Heck bpeezer, I think that is a pretty good pic, my standards aren't super high though.. My ripple came the same way, and I had to reprofile it, widening the bevel a lot in the process--it's been a great slicer since I took it to 15dps.

 

[bpeezer]

Heck bpeezer, I think that is a pretty good pic, my standards aren't super high though.. My ripple came the same way, and I had to reprofile it, widening the bevel a lot in the process--it's been a great slicer since I took it to 15dps.

Thanks Fish! This is really my biggest issue with CRKT, they seem to consistently make their knives too thick behind the edge. I'd like to see a shot of the ripple at 15dps, I bet the bevel looks pretty wicked now.