Observations on reprofiling S30V

dsvirsky

dsvirsky

Joined
Aug 2, 1999
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I have a small folder (2 1/4" blade) where the maker put the edge on at a 45+ degree included angle. Mostly using diamond hones (coarse and fine), I back beveled the blade to 30 degrees included, with a secondary bevel at 40 degrees (for now). It actually wasn't too bad a job -- easier, I think, than with BG42.

On the other hand, ceramic hones (Sharpmaker and yes I cleaned them first) didn't seem to have any substantial affect on the steel, other than to polish out the scratches from the diamond hones. Which would be consistent with the fact that I can get a great edge with CPM steels using a ceramic hone for touch ups, but can't get them sharp in the first place, unless I use a diamond hone
 
I have one of those Spyderco Natives with the S30V steel and used to just "sharpen" it using the ultra-fine hones on the Sharpmaker and eventually even stropped it on a mousepad with .3 micron AO grit lapping film. The edge dulled quickly after each Sharpmaker sharpening, but lasted for a while after mousepadding. Then, I used the edge on some food, washed the folder, oiled it, and put it away for a while. When I had finally wiped off enough oil to dare pocket carry (a little Militec goes a huge way. And I thoroughly washed the knife before food prep because I use such oils) I noticed that the edge was full of teeny chips!

Apparently, what I had been doing with the UF hones and mousepad was realigning a blunted edge with only the teeniest bit of stock removal occurring. I'm guessing that because the edge-life didn't live up to the hype of S30V, but it did live up to the hype of 'steeling'.

So, there, I saw the ceramic hones making no difference.

To restore the edge, I worked on the brown corners and brown flats until the edge was shaving sharp. Then, I went on to the fine and ultra-fine hones. Now the edge is stronger and more durable.

So, there, I saw the ceramic hones being very helpful.

OTOH, diamond hones are noticeably quicker.

Sorry for rambling.
 
After having sharpened and reprofiled countless knives (I do it professionally) I have come to the conclusion that when the knife comes shaving sharp from the factory, the edge will invariably not stand up to much use. I believe that the cutlers that put on the final edge are heating up the edge and weakening it by modifying the temper. In every instance, steels like vg-10, s30v, ats34 and the like, show some kind of edge deformation or micro chipping when used with the factory edge. Once I reprofile them very thin and get past the factory edge, they perform superbly.

S30v scared me at first with the microchipping untill I figured it out. Now, I like it above the rest, with vg10 placing second, and bg42 ats34 close by.

Thomas
 
Originally posted by zinn1348
After having sharpened and reprofiled countless knives (I do it professionally) I have come to the conclusion that when the knife comes shaving sharp from the factory, the edge will invariably not stand up to much use. I believe that the cutlers that put on the final edge are heating up the edge and weakening it by modifying the temper. In every instance, steels like vg-10, s30v, ats34 and the like, show some kind of edge deformation or micro chipping when used with the factory edge. Once I reprofile them very thin and get past the factory edge, they perform superbly.

S30v scared me at first with the microchipping untill I figured it out. Now, I like it above the rest, with vg10 placing second, and bg42 ats34 close by.

Thomas
Click to expand...

This is the most interesting post I have read for quite a while.
I have allot of knife sharpening under my belt, and have often wondered about this. Not many knives come from the various factories with hand finished cutting edges. More likely final sharpening is done on a belt, and thus heat.
 
zinn1348, thanks for the information. Yet another reason to never judge a knife on the factory edge! Every knife I get new is immediately sharpened on my Edge Pro. I don't care how sharp the factory edge is, only if it's thin enough to be easily sharpened. When I have to spend an hour reprofiling I tend to get a little frustrated.
 
I wish there way a way to research this issue. In my mind's eye, I can visualize workers setting at a bench with thousands of knives lined up, doing piecework....you know, do a hundred pieces an hour, and you get a certain wage, do 150 and your wage goes up. With that being the case, it's easy to see why there are differences in what comes out of the factory, and the quality control involved.

Obviously the factories have to work a little softer for their manufacturing processes.


Initially, this topic dealt with factory knives. I will make the observation that the knives that I have from Simonich, Rinaldi and Peter Atwood are a different breed concerning the issues in this thread. Very little reprofiling was needed(the Atwood needed none) and the durability is superb.

This is the same for all of the steels out there though, get a custom heat treat and the results are dramatic.


Those knives have a different(better?) heat treat, a few points harder on the RC scale. Reprofiling may take a little more work, but it's worth it. I've noted that these knives are less prone to develope stubborn wire(feather edges) than the factory specimens.

Bye the way, I mostly sharpen free hand on diamond hones..... Sharpmakers don't give me the results I like, other than on serrated edges. Also, I hate to waste time cleaning those ceramic rods. The best method I've found with the Sharpmaker is to use the diamond sleeves, and go directly to the white rods. Then strop on green rouge.

Thomas
 
thombrogan :

To restore the edge, I worked on the brown corners and brown flats until the edge was shaving sharp. Then, I went on to the fine and ultra-fine hones. Now the edge is stronger and more durable.
Click to expand...

This should be in the sharpening FAQ under troubleshooting. Many times when an edge fails to get sharp easily, or doesn't stay sharp for very long it is because the edge contains significant amounts of worn or weakened metal (or corroded or fractured). This can be readily steeled and thus develops a semi-sharp edge which is usually burr'ed to one side, and easily folds in use. The problem as you noted isn't one of type of abrasive per say but more of the grit.

-Cliff
 
Originally posted by zinn1348
Initially, this topic dealt with factory knives. I will make the observation that the knives that I have from Simonich, Rinaldi and Peter Atwood are a different breed concerning the issues in this thread. Very little reprofiling was needed(the Atwood needed none) and the durability is superb.
Click to expand...

Actually, the knife that started this topic is a custom, not a factory knife. My mistake was twofold: first, not ordering from someone like Peter Atwood or Rick Hinderer (not that I wouldn't want a folder from either Rob or Trace, but they're not taking orders) and second, not returning the knife when the maker ignored my specific instruction that I wanted the final edge bevels to be no more than 30 degrees, included angle.
 
This should be in the sharpening FAQ under troubleshooting. Many times when an edge fails to get sharp easily, or doesn't stay sharp for very long it is because the edge contains significant amounts of worn or weakened metal (or corroded or fractured). This can be readily steeled and thus develops a semi-sharp edge which is usually burr'ed to one side, and easily folds in use. :confused:[/QUOTE]


You're kidding????????:rolleyes: :eek: :rolleyes:

Right???? :(
 
No, it is one of the more common problems, propogated by common use of v-rods which tend to easily induce deformation rather than abrasion as thombrogan noted in the above, but fine honing in general will lead to such issues, steeling of course induces such behavior almost instantly. A similar side issue is the loss of aggression on such edges, typically while they will be shaving sharp they will have little to no edge aggression on a slice. The solution is the same there, just hone off the worn metal.

Once you realize the nature of the problem it is easily dealth with, but for people just learning how to sharpen it can be frustrating as they take a knife which is just a little less than perfect, touchup it up to a nice level of sharpness but it goes dull fast. They repeat this a few times and then conclude that the steel is crap. Which is why one of the first things you should try if the edge holding is low is to grind the edge back a little. Of course if you can check the edge under magnification you can take some of the guess work out of the process, but this assumes that you know what a proper micro-tooth scratch pattern looks like, which a novice probably doesn't.

Of course we are not talking about vast metal removal, < 0.1 mm deep is all that is necessary usually. In extreme cases it can be worse. Awhile ago I sharpened some fillet knives which had extreme levels of edge corrosion. Even after all visible rust had been removed the edge would not sharpen. I formed a burr, cleaned it off, and the edge would not get sharp. How do you think someone starting to sharpen would react to this? Under magnification the edge could be seen to still be breaking apart. It took about a mm or so more of metal which had to be ground off before the micto-teeth would form clean and then it could easily be sharpened to any degree of polish required.

-Cliff
 
I'm trying to follow this thread as best I can and get about 90%. I recently purchased an expensive double edged tactical blade in S30V. It is recurved and I am having a frustrating time getting the edge hair popping sharp. I am currently using a spyderco sharpmaker and even went to the trouble (and expense) of purchasing the diamond hones.

Would it be safe to assume that using the back bevel of 30 degrees to thin out the edges somewhat utilizing the diamond hones followed by sharpening on the 40 degree side would be successful? You can't use a stone on this knife due to its curvature.
 
I can sympathize with you concerning the sharpening of recurves. They are bad enough without adding s30v into the equation.

I have learned that FOR ME, a little different method works well.

On the Sharpmaker, I take the brown rods which I don't use anyway, and slide the diamond sleeves onto them, and then reprofile free hand concentrating my efforts in the inner radius of the blade.
I primarily use the surface of the diamond hones closest to the corners of the sleeve. When I have the inner radius beveled to my satisfaction, I then work the whole edge. I work on one side at a time. When both sides are complete, I then advance to the white sharpmaker rods using the same identical sharpening angles. I find it is a mistake for me to change from 10-15 degree angles,to 30-40 degrees, establishing micro bevels. Especially on recurves. Sometimes, I have to go through the process twice to get it right.

I don't have a lot of success with sharpening aids, so don't use them except on special items.

For recurves, once they're profiled correctly, I maintain them with DMT diamond coated sharpening steels. I have a red mesh one, and a green mesh one. Usually the green is all I need.

One thing.....I will make 20-30 strokes on any diamond sharpener, then I wipe it with a wet paper towel. I have found that it helps them cut with better efficiancy. I do sharpen dry on these hones.

Good luck with your efforts,

Thomas
 
Of course we are not talking about vast metal removal, < 0.1 mm deep is all that is necessary usually. In extreme cases it can be worse. Awhile ago I sharpened some fillet knives which had extreme levels of edge corrosion. Even after all visible rust had been removed the edge would not sharpen. I formed a burr, cleaned it off, and the edge would not get sharp. How do you think someone starting to sharpen would react to this? Under magnification the edge could be seen to still be breaking apart. It took about a mm or so more of metal which had to be ground off before the micto-teeth would form clean and then it could easily be sharpened to any degree of polish required.


That sounds good..........but in reality it is only a theory

Based on one experience!!!!! :p
 
Originally posted by Cliff Stamp
This should be in the sharpening FAQ under troubleshooting.
Click to expand...

Are you saying that, had I looked, I should it find it? Or that it's not there and it should be. I stole the idea from you, sir, and it didn't disappoint me.

Tom,

If it works, how is it just a theory? Does it break down in practice?

I've had to use it on my Spyderco brand knives. They came new in box with the sharpest edges I have currently used. Then, after so much use, they'd dull a little and not always last as long as the original edge between touch ups. Using the Sharpmaker's instructions (40 strokes per corner, 40 strokes per flat, change to finer grit and repeat) had the edges last a little longer, but not as good as new. Getting to arm-hair shaving sharp on the more corner of the more coarse stones before going any further produced an edge that outlasted the original. I understood the theory, but I noticed no difference in practice. Where's the flaw in this case?
 
What you two are discussing is just a theory......dispite your alleged results........What you really need is a 100x microscope, a number of knives made of the same material, heat treated by the same specs, and view the results ALONG THE WAY as you clean up the dulled edges. I have had NO such experience with S30V whatsoever....however, I use a $2500 variable speed Hard Core Grinder and do not hand sharpen anything. I start sharpening dull S30V with dull 220 grit premium 3M ceramic belts, then polish with a dull 400 grit blue belt, then over to a medium felt wheel loaded with green chrome rouge.
I also have found that S30V is a VERY tough material and resists abrasives very well, and works best with a nice thin blade (it is quite tough so I can do that) so that the edge is pretty easy to put on.

I use my BUCK TNT (S30V h/t'd by Paul Bos) every single day for a bunch of assorted tasks and when it gets dull I sharpen it and it lasts a long time each and every time. I have NO idea what you are doing that is causing problems but to be a scientific experiment it needs to have recorded data and must be repeatable and verifiable.

:confused:
 
I will add my 2 cents worth, whatever it's worth.:)
My S30V large Sebenza originally came with a thicker edge than I usually prefer, esp. the second half toward the belly and tip. I only had my 204 Sharpmaker and used mainly the coarser gray rods to reprofile first the upper half of the blade, then the whole blade. It did take quite some time, and after several stops and restarts I finally got the edge bevels thinned out to satisfaction.

I did mostly a 15 degree (30 degree included) angle to remove the shoulder then finished with the 20 degree (40 included) angle. Keep in mind I did this more than once over many days until finally satisfied. The edge bevels are still slightly convexed but are considerably thinner and cut very well now, yet seems durable and tough enough for most of my uses.

I feel the S30V steel was not very difficult to resharpen in itself; what made the process difficult was I was reprofiling, which has been the same when I've had to reprofile thick edges of ATS-34, 154CM, ATS-55, etc. And probably the hardest thing I found was to totally remove the wire edge at end of the process. I merely lightly laid the edge against the fine rods at a steeper angle and lightly stroked the edge down each side many times, then stropped on a piece of cardboard from a small legal pad. The S30V wire edge seemed much more stubborn to remove than others, but I think the entire process seems well worth the effort and was a learning experience for me about sharpening.
Jim
 
I did a microbeveling with a brown oudoor rod. So easy, i first thoght, the steel is soft.

I use to test steels by cutting thru Pampers boxes. Different steels get diffeent numbers of little chips by doing this. My BM D2 just two, my SR101 a lot. All chips are not noticable by eyes, but you feel them running down the edge with the fingernail. The S30V: not one.
 
Originally posted by tom mayo
What you two are discussing is just a theory......dispite your alleged results........What you really need is a 100x microscope, a number of knives made of the same material, heat treated by the same specs, and view the results ALONG THE WAY as you clean up the dulled edges.

<snip/>

I have NO idea what you are doing that is causing problems but to be a scientific experiment it needs to have recorded data and must be repeatable and verifiable.
Click to expand...

Oh, then, well, I'm not even at the theory stage yet. I'm not even at the hypothesis stage. OTOH, I have seen the phenomenon in blades made by Benchmade and Spyderco: Long lasting factory edge that, when it finally goes, responds better to full resharpenings than it does to 'touch-up' resharpenings. I've been on a Spydie kick lately, so I've noticed and corrected the problems mostly on my Spydies.

Here's the thing, though. You read Cliff's statement and say "Nice theory", but no theories or hypotheses were mentioned. The other thing is this:

Originally posted by Tom Mayo:
I have had NO such experience with S30V whatsoever....however, I use a $2500 variable speed Hard Core Grinder and do not hand sharpen anything. I start sharpening dull S30V with dull 220 grit premium 3M ceramic belts, then polish with a dull 400 grit blue belt, then over to a medium felt wheel loaded with green chrome rouge.
Click to expand...

By your own words, you completely resharpen your blade each time. So, while deriding certain techniques as theories and claiming not to notice weakened edges when touching up S30V after a factory sharpened edge has degraded, you've been completely resharpening your blade.

C'mon, Tom, if two belts and a felt wheel full of green rouge is your idea of a 'touch-up', then your idea of a complete resharpening is going to be a lot different. Since you're not doing what we've been talking about, of course your experiences are a lot different. If you completely replace the tires on your car every 4000 miles, you're going to think that rotating tires every 6000 miles is some cutesy theory, too.

Since you made it a point to declare what we've been doing a theory of only one man, you may want to reread and notice that almost everyone in this thread has noticed the same phenomeon. None of us who touched-up our blades with fine ceramic hones instead of two belts and rouge are world-class knifemakers, but that doesn't make our experiences any less real.

You're a good man, Tom, probably a great one. I love your work and most everything you've written here, at KF, and at USN. Your dedication to your family, friends, and country have been nothing but exemplary online (I don't know you offline, so if you're otherwise there, which I highly doubt, I couldn't say or vouch). Why the big push to invalidate what Cliff wrote in this thread? Why the call for it to require examination under a microscope and standardization for use as an experiment? Could you just lay that agenda bare on the table of this thread and be done with it? In the context of our discussion and furthered by your description of your experiences, it was uncalled for.
 
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