Share your experience with 15V

[alphaneuron9]

You get what you pay for.

Bonded stones are completely different than electroplated stones.

Just like with knife steel, It's not just the carbides or with stones the diamonds that are so important, but also the matrix that supports them.

With electroplated stones It is not a renewable surface. Once that single layer of diamond or CBN wears out you'll need to buy a new one.



Figure 1a: brand new Atoma, abrasive grains rest on surface causing rough surface finish.


Figure 1b: used Atoma, less cutting performance due to reduced abrasive grain volume from tear out and dull grains. Corrosion due to loading.

When you buy a resin bonded stone it is at minimum 1 mm thick with abrasive all the way through with a renewable surface that can be conditioned.

Diamond and CBN grains will go dull. Just because they are super hard, doesn't mean they can hold their sharp cutting facets forever.

When dulling happens, it's nice to be able to condition the abrasive grains on the stone surface without tearing everything out of the plating.

Electroplated stones are more prone to tear out.



Figure 2: A closer look at the abrasive grain tear out on the atoma from use, some areas of diamonds have been completely uprooted while others have been sheered off leaving a flat diamond "root" behind.

Electroplated stones will also will make an extremely rough surface finish at the SAME grit rating since the plated abrasive grains protrude so high from the plating allowing them to penetrate deeply into the steel that is being cut.

A resin diamond stone will leave a brighter, smoother finish with less deep scratches than a plated stone. The abrasive grains are also more secure since they are bedded into the resin stone rather than sitting on top surface like on the plated stone.


Figure 3: a CGSW resin bonded diamond stone, diamond abrasive (yellow) in a "sea" of resin (white)


In conclusion, the resin diamond stones will also have more longevity, stay sharper and will be less prone to premature damage and can be reconditioned when comparing to a plated stone.

So, a plated stone is not simply a cheaper option, it's a completely different option.

23% of the volume in the 15v is harder than ceramic.
When shaping a sub micron area at the apex it's nice to be able to cut all features to shape rather than only 77% of it.

Use bonded diamond/cBN.

Don't waste money on atoma/DMT
Those work best for flattening ceramic stones.

This isn't 2003 anymore, it's 2023 and there are a lot of bonded diamond/cBN products on the market.

Such as the venev resin bonded diamond from Gritomatic, Nanohone resin bonded diamond. Columbia Gorge Works Resin Bonded diamond etc

I'd love to try the bonded stuff, but the only reason I'm even considering the Atoma line is because of how cheap electroplated diamond hones have gotten since 2003.

Shawn,
This response is so professional it seems quoted from a journal article. Are you publishing these findings?

[alphaneuron9]

Spectacular series of input and discussions, gentlemen. Thank you all very much.

[kennbr34]

Figure 1b: a CPM 15V 400 grit Silicon Carbide edge, shows signs of fatigue at apex due to adhesive wearing.

That actually looks pretty identical to what I'm seeing on my edges through the 60x-120x loupe.

As far as corrosion goes, I had an unfortunate accident with some bleach with my Manix. I really didn't like it, so I ended up forcing a patina.




The steel has held up fine for me. I have it ar about 15 dps. I encountered some micro chipping when I cut up a kitty litter box and it hit some of the clay. Sharpened out really easy though. But it also tends to chip on my coarse stones, though only big enough to see through 60x magnification.

I have definitely got more use out of my mule...



But it's mostly just been used for shredding up cardboard. It cut up about 2000 feet of cardboard with it before it lost a good three finger bite, but it would still cut pretty well.

I really like the 15V but honestly I don't find the wear resistance to be that much higher than 10V/K294. It does however seem to take a much toothier edge off my DMT F finishing hone. Very bored on a three finger test, though weirdly a little lower on the BESS score than 10V/K294. Meanwhile 10V/K294 finishes up a little easier on a ceramic whetstone.

Interesting comparison notes with 10V... maybe ideal vanadium carbide amount is somewhere in between?

Fascinating effects of bleach on the steel. I take it that's how a finger print got marked on the steel (gives me creative aspirations in terms of true concept of "making it your own" regarding customization... what's more unique than your own finger print right on the blade) ha ha ha.
did you clean it before forcing the patina? I take it those are before and after shots... turned out beautiful. what did you use to force the patina? vinegar?

kitty clay sounds pretty coarse. I have a little chihuahua that doesn't bark or bite. People say its a cat that responds like a dog.

great entry!

It's interesting to me that the edge retention between 10V and 15V is so close, but it mirror's Larrin Thomas's CATRA results. 15V has about 10% more wear resistance in his chart, however, that is compared with 10V that is quite hard. Given how difficult it is to even find 10V, let alone 10V hardened to a high level, I think it's good Shawn worked with Spyderco to produce a heat-treat protocol that will allow them to make it viable for mass production. Otherwise I'm not sure we'd really have seen either steel have much chance being made en masse.

Yeah, I think it's the chlorine from the bleach which had such a corrosive effect. I forced the patina by using some Rustoleum Rust remover gel and just soaking the blade in it for a few hours. It's basically just phosphoric acid. Didn't need to clean it up prior to that at all, but it did really alter the smoothness of the stone-wash finish.

The other thing about that kitty litter box is that it was some very thick cardboard. Meant to support 40 lbs of litter, so it was double-walled, with lots of glue and stuff as well. Definitely a lot harder use for it than it sounds.

[JoviAl]

I’ve got the 15V shaman and have been pleasantly surprised with its corrosion resistance. I douse it with KPL Knife Shield after each day’s work and it has yet to show any corrosion at all, not even galvanic (I’ve had S90V galvanically corrode in my pocket over the course of a single day at work. I’m in Singapore mind you, so it’s pretty damp in there!).

As for toughness and chipping at 15DPS I’ve had zero issues, although the shaman is fairly thick blade stock. Most of my cutting with the Shaman is carving/shaving wood, which it does with great aplomb. I still prefer Magnacut, but 15V is no slouch.

Al!
Good to hear from you! I told you about my "pseudo" cousin living in Singapore. Wow I'd like a pic of the shaman after shaving wood. Sounds like youre having a pretty good experience despite the singapore humidity. Its currently 94% humidity in singapore according to "Alexa"... Its rare that it gets that high in the Fla Keys... daily KPL shield, eh? whatever works, right? tell me about the s90v galvanic corrosion? what happened there? was it with the phosphor washers? i don't think Ive ever heard of that...

this is exactly why I started this thread... I enjoy learning from your experience

Hey buddy,
Yeah - that KPL Shield is good stuff and food safe to boot. I buy it by the gallon through our procurement dept (I suspect they think I’m drinking it).

Alas, I do not have the 15V Shaman at work with me today, just my five most used (pictured). That innocuous little fixed blade between the Magnacut mule and the SE Caribbean is one of my all-time most treasured and used knives though - a PW Customs Harp in Elmax and burlap micarta with CF pins. It was my second custom knife from Petr (not my last - don’t tell my wife ) and far greater than the sum of its parts.

As for the S90V it would/will begin to galvanically corrode and visibly rust orange where the blade hits the stop on my CF Yojumbo. It’s one of my favourite knives though, so I just baby it when using it

[Deadboxhero]

Shawn,
This response is so professional it seems quoted from a journal article. Are you publishing these findings?

I appreciate the compliment. Just sharing my knowledge and experience with you all. I am grateful for how much all of you enjoy the 15V.

[Danke]

No chipping. Picks up patina faster than Cruwear but nowhere near as fast as M4.

Are you using anything to protect from corrosion? Do you live in humid/salty environment?

I am in a temperate rain forest type of area. So wet but not tropical humidity. I use Boeshield T9 on the pivot.

The only place I tend to see rust is on the jimping or on the pivot when I take the knife apart.

[alphaneuron9]

Anyone taken the 15V hunting? I can imagine it would be ideal for skinning deer. No more sharpening during the field dressing... I bet one could skin 3-5 deer or so before needing to touch it up.

And the fat would protect it from corrosion...

[alphaneuron9]

Taking the 15V hunting may be a good way to boost sales... although with how fast these sold, I don´t think Spyderco needs my 2 cents worth in marketing... lol.

[Sharp24/7]

True, I always forget compounds/lapping-films are an option. I would very seldom want to have a finish that polished. I'm just curious how these carbide rich steels may perform with one. I would definitely want an extra coarse option though.

Well, using a strop doesn't just instantly wipe out the scratches that are created. Loaded stropping just helps refine and enhance, it cannot create. If you have made a good edge off the stones stropping will add some push cutting to the edge and will reduce the weak metal hiding at the apex which can prematurely kill an edge when deformed in use.

If the edge gets worse after stropping with good technique, it wasn't a good edge to begin with.

Speaking of which, I know you have mentioned it before, but since this thread is about the 15V experience people have had so far, how do you feel the bonded abrasives affect things with 15V versus ceramic hones or electroplated options (other than the deeper scratches)? I believe it was you who mentioned to me the burnishing effect created from ceramic whetstones.

I've been given a lot of direct feedback from sharpeners over the past year on the Spyderco 15V. Keep in mind, an entire melt of CPM 15V was used so there's a lot of CPM 15V knives out there in the wild.

It seems in some cases, some people complain about electroplated stones generally not being able to get the knife as sharp (push cutting sharp) They can get it really aggressive but they don't enjoy the lack of refinement like can be achieved with ceramic waterstones. Yet, with ceramic waterstones they feel like they don't get it as sharp and when they do the front end, hair shaving sharpness doesn't last as long and seems to go smooth faster.

When people use bonded stones, it removes both complaints. So, it's an easy solution to give and it makes sense when you look at the science of it.



When we investigate further we see the problem is with the softer stones is there is a lot of adhesive tearing at the bevel when sharpening an extreme steel like 15V which translates to a lower performance apex. It's like the abrasives aren't quite hard and sharp enough to cut the apex as crisp.

*


Figure 1: On the left, adhesive tearing on edge bevel is observed also the apex is not cut as flush. On the right, more uniform scratch pattern on bevel and apex is cut more evenly and flush.


Figure 1a: a highly polished and refined edge in CPM15V, the grey dots are carbides with an average size of 3um. For reference a red blood cells is 8um.


Figure 1b: a CPM 15V 400 grit Silicon Carbide edge, shows signs of fatigue at apex due to adhesive wearing.

“Note, This is from sharpening a dull knife, not just honing an already diamond sharped edge on soft abrasive which has a different effect.”

Thanks for all the info, Shawn. Would you mind briefly describing what the effect of a soft abrasive on diamonds sharpened edge would be? Thanks again!

John

[Albertaboyscott]

That pict of the highly polished 15v edge is super cool. Reminds me that I still have a long ways to go in my sharpening.

[Deadboxhero]

“Note, This is from sharpening a dull knife, not just honing an already diamond sharped edge on soft abrasive which has a different effect.”

Thanks for all the info, Shawn. Would you mind briefly describing what the effect of a soft abrasive on diamonds sharpened edge would be? Thanks again!

John

As Todd and Gabe have shown, it cuts matrix and exposes carbide.

The Spyderco factory edge has this feature also.


CPM 15V factory edge, the white dots are the exposed carbides from finishing the edge, matrix is worn away exposing carbides.

[Sharp24/7]

“Note, This is from sharpening a dull knife, not just honing an already diamond sharped edge on soft abrasive which has a different effect.”

Thanks for all the info, Shawn. Would you mind briefly describing what the effect of a soft abrasive on diamonds sharpened edge would be? Thanks again!

John

As Todd and Gabe have shown, it cuts matrix and exposes carbide.

The Spyderco factory edge has this feature also.


CPM 15V factory edge, the white dots are the exposed carbides from finishing the edge, matrix is worn away exposing carbides.

Thanks Shawn! I’d forgotten all about that Science of Sharp article!

[alphaneuron9]

Anyone "hard using" their 15V?

[ladybug93]

Anyone "hard using" their 15V?

how do you define hard use? one man's hard use is another man's daily cutting requirements.

my use tends to be on the lighter side, but i did a little carving with mine over the weekend, and as mentioned previously, i've stripped some wires and cut zip ties, etc.

to me, hard use would be anything that causes, or can cause, damage to the edge beyond the scope of normal dulling, like stripping wires. it would also include strenuous forces. for example, i wouldn't call cutting cardboard hard use, but i would if it was thicker cardboard and continuously being done over a period longer than just breaking down a couple of boxes to fit in my recycling bin.

[Ex-Phys]

Gentlemen,

I just wanted to let you know how much I appreciate this discussion. I am a scientist from a different field, exercise physiology. I am used to looking at cellular and sub-cellular microscopic biopsies. The evidence presented with this discussion, as well as the links to the science of sharp articles really peak my interest.

I thought I joined this forum several years ago, but can not recall my previous user name. I have been collecting knives, mostly Spyderco, since 2006-2007. I enjoy experimenting with different steels. We are fortunate that Spyderco caters to this niche market. I have a PM 2 in 15v and would love to see 15v with Shawn’s heat treatment in a Para 3 or Native 5.

Anyway, thanks again for the discussion. I will continue watching this space for more.