S30V Native - eternal wire edge??

BladeChemist

BladeChemist

Joined
Aug 19, 2010
Messages
261
Argh.. I spent 3 hours today in two separate sharpening sessions with the Edge Pro and my new Spyderco Native in S30V. Reground to 18 degrees, 36 degrees inclusive, all the way down to 6000 grit and a mirror edge. Twice. Shaved hair for a moment but suddenly dulled to the point where it tore magazine paper.

I know it's a wire edge of some kind (I've seen at least one other thread on this), but how to remove it is baffling me. Do I need to get/make a strop?
 
use alternate strokes and reduce progressively the number of strokes per side all along your sharpening and on each stone. like 15/side, 12/side, 10, 8 and so forth until you reach one check for burr during the process, if you don't have one at 10 restart, then switch stone and count again.

this is what i do when sharpening my japanese kitchen knives. they are sharpened at very low angle and get very stubborn burrs. this method let you fragilise the burr from the start, when you reach the polish tape you should be done with it. if not try gently slicing a cork or a piece of hardwood between each stone. shouldn't be necessary though.
 
That same thing happened to me with a Benchmade Skirmish, turns out it had a bad heat treat. They replaced the blade.
 
Steel is fatigued at the very edge. Stropping won't do it. It'll just realign that wire edge back to its old weak self, ready to flop over again, until it breaks off.

What you need to do is get back to good steel. Lightly run the edge down a stone, as if stone were made of jello and you were trying to slice it in half. This will destroy any edge you have. Which is a good thing, because your current edge is crap. If the edge will reflect light, then you are good to start again. Traditionally, the advice is to sharpen one side until you form a burr, then sharpen the other side. The risk of doing this, however, is that you simply end up right where you started, with a floppy, weak edge.

Instead, make sure your abrasives are sharp and clean, not worn and loaded. Then sharpen one side, but not until you make a burr. Then sharpen the other side. When that edge no longer reflects light, and has no burr, you should have a strong and sharp edge that won't flop over in regular use. If you wish, at this point you can strop, to give that edge the final razor polish.

It isn't uncommon for factory edges to be relatively weak out of the box. My own Native suffered the same thing when I first got it. It took a few tries to realize that the edge was simply weak, probably from factory sharpening. Once I got down to good steel, it's been fine ever since.
 
pwet said:
use alternate strokes and reduce progressively the number of strokes per side all along your sharpening and on each stone. like 15/side, 12/side, 10, 8 and so forth until you reach one check for burr during the process, if you don't have one at 10 restart, then switch stone and count again.

this is what i do when sharpening my japanese kitchen knives. they are sharpened at very low angle and get very stubborn burrs. this method let you fragilise the burr from the start, when you reach the polish tape you should be done with it. if not try gently slicing a cork or a piece of hardwood between each stone. shouldn't be necessary though.
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I'll try something like this tonight. I was sharpening until a bur formed, that's for sure. I was trying a variation of what you mentioned, removing scratches on both sides, then going over each side once more with less strokes, then finally wetting the stone down and going over each side 3-4 times. I also repeated this technique with the polishing tapes.

Tonight I'll concentrate on ramping down both sides at a more gradual rate. We'll see what happens then.

Right after the Native was done I tried my luck with a fillet knife (5Cr15MoV) at 15 degrees/side and it came out wonderfully. Granted, it was extremely easy to sharpen compared to the S30V.
 
Nope, still won't go away. Cut into the 220 stone to remove the edge, then went through the process again, even doing the 7-5-3-1 to both sides with each stone. Tried wet stones and dry stones, heavy strokes and light strokes. Didn't even bother going past the 2000 polish tapes because it was so obvious that the edge wire/rolling just wouldn't go away. My EDC in AUS8 was also set at 18 degrees per side, and I was able to quickly bring it back up to hair popping sharpness. The Native, on the other hand, cut roughly into a single layer of cardboard and on the third cut got stuck in the card board. In frusteration I used the ceramic steel on the edge and suddenly it became shaving hair sharp. After a few good cuts in magazine paper, it starts tearing again and no longer shaving hair. I've never had such a stubborn edge before.

Now, I have another knife in S30V from Benchmade which acts nothing like this...it feels like I'm sharpening a rock. Maybe this particular Native missed getting a proper heat treat?

If I ask Sal in the Spyderco section, what do you think he would say to me?

I mean, is s30v supposed to be this tough?
 
Compared to BM S30V most is harder to sharpen and will seem to perform better at coarser grits. BM S30V as you may notice seems to be best at a very high polish.

A bad HT is not something I would expect from a spidie and from my experience their S30V is fairly consistent. Companies like spyderco and kershaw seem to put more effort into their heat treatments so to actually find a bad one would be like winning the lottery, possible but not likely.

S30V is a steel that has a learning curve of its own and is usually the steel most try first mainly because of its wide use. Learning that its going to take 2-3x as much time is usually the issue when coming from a lesser steel.

Have you tried a microbevel? I find S30V to perform nicely with a acute main bevel (10-12 per side) and a steep micro (20+ per side) usually applied by a spyderco UF ceramic and finished on a 1 micron strop. usually feels like a utility razor after that and has excellent edge holding.
 
I will take your suggestions to heart and try again tomorrow. Probably put a microbevel on it.
 
BladeChemist said:
I will take your suggestions to heart and try again tomorrow. Probably put a microbevel on it.
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I have a Benchmade Kulgera in S30V, but I can't really comment on how easy it is to sharpen compared to Spyderco's S30V. All I know is that I got pesky burrs with it for a while too, and then read a post that detailed a deburring method where you increase the angle of your stroke by about double on your finest abrasive, and make one or two passes one each side at extremely light pressure ( even less than the weight of the knife, as if it were barely touching it basically ) and by doing so you'd basically dull out the edge a little and get ride of the wire bit.

It's been working well for me so far; you still have to do a bit of sharpening on the final abrasive afterwards since you have dulled the edge out, but it's easier to actually get the thing off versus just making it stand straight out on edge. The real energy saver with it I found was that, if I accidentally rolled it stropping and couldn't get the burr off on chromium oxide, I would basically undo all my work if I used my stone or something else that was coarser. By just dulling the very edge out a little bit you can instead continue on your final abrasive without undoing any work, as if it was just natural wear. I know you already tried to do that with the 220; but the difference here would be you're removing far less material, and if there's any part of your technique in between initial sharpening and final sharpening that's causing you to form the wire then you'll skip it.
 
Are you possitive its a burr? S30V had a reputation for microchipping for some time, which could also explain the performance you've had. If it's a burr, try cutting into a stone to remove it again, and maybe again. Sometimes it takes a couple rounds of this to get past the damaged steel. The microchipping has been known to go away with this treatment as well.

Try raising a burr as normal, then cut into a stone to remove it. Increase your angle about 5 degrees/side and do light alternating strokes 1/side, on fresh, clean, flattened if necessary, stones. The idea is to sneak up on the edge after removing the burr by cutting into the stone. Test the edge for sharpness frequently, as you don't want to overshoot.
 
Alright, sharpened sitting down for the first time. Attached the E.P. to a metal folding chair and plopped down on the couch. That must have done the trick, because at 320 grit the Native was already hair popping sharp and when finished at 6000 grit it divided cheap toilet paper. I was surprised how sharp it got so quickly- think I'm in lust again.

Repeated the same for the Gale Bradley folder in CPM-M4 with success. So..my insecurities are put to rest and everything works. Thanks much everyone for the pointers.
 
BladeChemist said:
Alright, sharpened sitting down for the first time. Attached the E.P. to a metal folding chair and plopped down on the couch. That must have done the trick, because at 320 grit the Native was already hair popping sharp and when finished at 6000 grit it divided cheap toilet paper. I was surprised how sharp it got so quickly- think I'm in lust again.

Repeated the same for the Gale Bradley folder in CPM-M4 with success. So..my insecurities are put to rest and everything works. Thanks much everyone for the pointers.
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You are making the wait for my edge pro much more painful. :grumpy:
 
do you have an idea what actually happened ? besides changing position ? how did it affect your sharpening ? i'm curious.

glad it worked anyway.
 
pwet said:
do you have an idea what actually happened ? besides changing position ? how did it affect your sharpening ? i'm curious.

glad it worked anyway.
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Darn, I thought I discussed what I did but apparently I did not. I tried several things to destroy the wire edge. First of all, I cut the spine off a mail order catalog which seemed to turn the wire edge ragged, then proceeded to very lightly destroy the wire edge using a high angle and 2000 grit (very gentle pressure). Then I started back at 220 grit, and worked evenly on both sides using very light pressure until I could see that the edge damage was gone. Then I sharpened as normal, albeit using lighter pressure than usual.

It was a blast, and I was sharpening in a very comfortable position, so that may have affected my technique. I don't think I want to sharpen standing up again. Oh, and I spent the rest of the evening push cutting magazine paper just to hear that quiet "shhhhhhhh" and watch the sliver of paper fall away.
 
I just went through a similar process with a Kershaw Barrage in 14c28n (I have no idea what the quality is of this steel but it seems very similar to 154cm or ATS 34). Worked it up through a progression of finer stones after reprofiling at 23 degrees inclusive. Raised a burr at each progression and thought I'd eliminated it prior to moving on. Got to the hard Arkansas and couldn't get rid of it to save my butt. Very uncommon for this to happen, the hard Ark usually raises a very small burr that is very easy to eradicate. My loupe is a 10x hobby store special with a cloudy lens, but even so I could see something wasn't right with the supporting steel behind the edge. It was all fatigued leftovers from the reprofiling. Had to raise the angle up a few degrees, grind it off, and drop back down to a soft Arkansas. Brought it back up to the hard and it cleaned up perfectly. Next time I change an angle I'll remember to double check the edge coming off the first stone. Seems to me I remember reading something Knifenut once posted about taking a step back in a progression to make sure the edge was properly cleaned up and all the coarse scratches from earlier steps were completely gone...
HH
 
Update to the previous - Wire edge is not completely gone. Dug out my 30x loupe and its still there. Reground the edge at 30 degrees inclusive thinking that maybe 23 is too steep for this steel (?). Still can not eliminate the burr, though it does get very small. Tried using Arkansas and finally a DMT stone. Am coming to the conclusion that this knife has a bad heat treat. I cannot remember any time in the last fifteen years that I couldn't get a clean, burr-free edge. Its a fairly cheap knife, but I'm still considering sending it back to Kershaw just to see what they have to say about it. Likely they're not going to rush it over to their QC department in a red envelope for a detailed report, this one may wind up replacing my Gerber paraframe in the bottom of my tool box.

HH
 
Addendum to the update. After doing some reading about Kershaw's 14c28n and their rep for high QC in their heat treating, I decided to go at it one last time. Ran through my progression (Washita, soft and hard Arkansas) paying extra attention to burr and scratch removal at every step. Resulting edge is as good as any I get from other steels and clean at 30x. Order is restored to the galaxy. And they say the definition of insanity is to do the same thing and expect different results...
HH
 
Lighter force is a major key for me in avoiding troublesome burrs. This is also known as, "let the abrasive do the work."
 
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