Waterstones for super steels as well as a comment or 2 on diamonds.

[Spartan00]

Hi all . Just wanted to talk a little bit about water stones and super steels.

Yesterday I decided to sharpen my spyderco k2 (10v).
I had pulled a lot of my stones out for lapping and decided to try a few of them on the 10v .

First stone I tried was a king 800. I did about 30 passes per side and checked my work, you could hardly tell that anything had been done . First time I've ever felt this weird sensation on the stone . It almost felt like the steel was cutting the stone .

Next up shapton pro 320 . It cut the steel but not like I'm used to with this stone . I used the 320 to get rid of some corrosion on the whole blade .

Then I tried the bester 1200 it cut the steel like it does with any other steel . Love these bester and beston stones they are nearly on par with shapton glass ,but a little cheaper .

After the 1200 I tried shapton glass 1k and 4k . They too cut the steel no problem.

So I've heard Jason b. Talk about diamonds and heard other folks talk about diamonds and how certain steels don't need them . So what happens when you actually use diamond plates on a steel that is hard enough to handle them for lack of a better word .

Well I started with the dmt xc plate . Instead of the normal feel of the xc ripping and tearing the blade 10v almost felt like it was skipping over the 220 diamond . I did my normal sharpening routine and off the 220 grit diamond I had one of the sharpest and cleanest edges I've ever put on a knife .

On of those edges that actually gave my arm razor burn and bit into the skin it was so sharp . I could of stopped here and been fine ,but seeing just how sharp it was off a 220 diamond I was curios as just how sharp I could get it .

I went from the 220 to 325 then 1200 then 8000 dmt plates . I used ultra light pressure and did alternating strokes only maybe 20 passes per side .

The results are probably the sharpest knife I've ever sharpened . I don't do hht tests or anything like that ,the edge could push cut magazine paper at 90 degrees off the 220.

By the time I was finished I was doing effortless slow cuts in magazine paper with almost no sound .

I don't strop my edges anymore because I like to test myself off of just the stones .

So the regular sharpening guys in here what's been your expierence with "super steels" and water stones ? It's obvious to me not just any stone will cut any steel so what water stones do you guys use on these types of steels ?

I still think only certain steels benefit from multiple grit diamond sharpening. However on these crazy hard steels diamonds can make an edge that will amaze you . It's not really that real toothy edge you expect even off on an 8k diamond either . 10v on diamonds feels as smooth as a Waterstone edge .

Kind of a long post I know just curious and wanted to share .

 

[HeavyHanded]

Once I get into high Tungsten or Vanadium carbide content, the highest King stone that will still do a good job is my 800 grit.

My Nortons can handle these steels up to about 4k and then drops right off. My Juuma stones handle these steels very well up to 2k (the highest grit stone currently made in that series), but they are VERY hard stones. Freshly lapped you could easily cut yourself on the outside corner if the edge isn't chamfered.

My Suzuki ya deal well up to 2k (currently the highest grit stone in the series I have).

Personally though I agree with your assessment. This is what the diamond plates are best at and it shows. I have gotten good results (better than my waterstones) using SiC wet/dry over my Washboard on these steels, but again the effect diminishes the higher you go. This limiting factor holds true for my waterstones as well, at low to mid range the abrasives work OK and then they don't as the finish gets higher. Even tho I was able to whittle a hair on s110v with SiC wet/dry and SiC honing compound, the edge is a lot crisper coming off of diamonds.

There is another interesting observation - using non-superabrasives on supersteels yields a brighter finish at a given grit - 800 grit ANSI for example creates a pretty bright finish on HSS and high Vanadium steel compared to using on regular steels, even if both run to a fairly high Rockwell.

 

[Spartan00]

Once I get into high Tungsten or Vanadium carbide content, the highest King stone that will still do a good job is my 800 grit.

My Nortons can handle these steels up to about 4k and then drops right off. My Juuma stones handle these steels very well up to 2k (the highest grit stone currently made in that series), but they are VERY hard stones. Freshly lapped you could easily cut yourself on the outside corner if the edge isn't chamfered.

My Suzuki ya deal well up to 2k (currently the highest grit stone in the series I have).

Personally though I agree with your assessment. This is what the diamond plates are best at and it shows. I have gotten good results (better than my waterstones) using SiC wet/dry over my Washboard on these steels, but again the effect diminishes the higher you go. This limiting factor holds true for my waterstones as well, at low to mid range the abrasives work OK and then they don't as the finish gets higher. Even tho I was able to whittle a hair on s110v with SiC wet/dry and SiC honing compound, the edge is a lot crisper coming off of diamonds.

There is another interesting observation - using non-superabrasives on supersteels yields a brighter finish at a given grit - 800 grit ANSI for example creates a pretty bright finish on HSS and high Vanadium steel compared to using on regular steels, even if both run to a fairly high Rockwell.

I have Nortons in 1k and 4k I'm just not a fan of them. They cut well in my expierence but they are a little soft to me . I know it's personal preference but have you tried a bester? The bester and Norton cut nearly identical! Only difference is the bester is harder . You still can get a nice mud off the bester it just doesn't feel near as soft as the Nortons. They aren't shapton hard either . Hard to explain but they are great stones !

 

[Spartan00]

Also yes HeavyHanded. The finish is a lot brighter on super steels . The shapton 320 left the finish looking like a 800-1000 grit finish .

Shapton 320 is a unique little stone . It's been years since I tried other shapton pros IIRC though the 330 has a unique feel to it vs the rest of the shaptons.

 

[Obsessed with Edges]

In my own thinking, I tend to delineate stones that 'cut the steel' (meaning the steel matrix of iron + carbon only) from those that are capable of CLEANLY CUTTING EVERY COMPONENT in the steel, including the ultra-hard carbides. The ability to cleanly cut every constituent in the steel's makeup is where diamond always (always, always) has the advantage in sharpening high-wear steels. In steels with very high vanadium content, like S90V/110V, etc, the vanadium carbides might make up 9% or more of the alloy's volume. If trying to sharpen with stones that CAN'T actually cut those carbides due to inadequate hardness (natural, AlOx, SiC are all less-hard than vanadium carbide), this essentially means about 9% or more of the steel's makeup at the edge simply can't be refined, shaped or sharpened at all in reality. Instead, the inadequate abrasives being used are simply plowing the hard carbides out of the steel at the sharpened edge, at best; therefore, the high-wear advantages of such edges are diminished in the process, and the 'gaps' left by the ripped-out carbides leave the edge less refined than it could be. To me, it makes no sense to spend big $$$ on such 'super steel' blades, if the stones one uses are only capable of actually sharpening (thinning, shaping, refining) no more than ~90% or so of the steel's composition at the edge, therefore essentially shorting oneself out of the full capability of the steel's makeup. Might sound sort of convoluted in thinking about it this way, but the results seen in comparing the two never lie. It's more noticeable at refining-grit sizes (maybe ~10µ and smaller), but the difference in edge quality & crispness can still be easily noticed at coarse-grit sharpening stages (~220/Coarse DMT, for example), as referenced in the OP.


David

 

[HeavyHanded]

I have Nortons in 1k and 4k I'm just not a fan of them. They cut well in my expierence but they are a little soft to me . I know it's personal preference but have you tried a bester? The bester and Norton cut nearly identical! Only difference is the bester is harder . You still can get a nice mud off the bester it just doesn't feel near as soft as the Nortons. They aren't shapton hard either . Hard to explain but they are great stones !

I use the Nortons more as a second tier stone, tho find them to be pretty versatile. I generally use trailing pass only or at least emphasize the trailing pass and this reduces rapid wear and dishing. For a less frosted finish I use them splash and go, and this also reduces dishing and makes a crispier edge. I like them most for common carbon and stainless, as they make a very burr free edge for how fast they grind. Does take a bit more care to make a crisp edge to finish, so I don't stop at anything under the 4k - the 8k is a very good stone - nice polish and very fast.

I have the Juuma 800 and 2k, they are made for super blue, so handle tougher alloys very well, but are not user friendly on the more common stuff. In use they are a lot like a diamond plate, are so hard they can load up a bit and are less forgiving of burr formation and removal. Very little mud formation, so for traditional cosmetic waterstone use they are not the best choice.

The Suzuki Ya stones I have are like a harder version of the Nortons - fast and do not load, make less mud and produce a crisper finish with less effort - their 2k makes a finish comparable to Nortons 4k. Very nice feel. I misspoke earlier, I have the 8k in that series as well as the 2k and it is a great stone too. Again, very much like a harder more dish resistant version of the Nortons.


Either way, waterstones (with exception of the Naniwa diamond ones perhaps) are not a good choice on super steels at anything above a medium finish. I haven't used the Sigma PS2 so cannot comment. Still, if it ain't diamond or CbN it likely won't do a good job at higher finish values.

Edit to add:
I have noted improvement in edge retention using SiC wet/dry over AlOx based abrasives on HSS steels, though still at medium medium/fine levels of finish. If I had to work a bunch without diamonds I'd reach for a couple fresh sheets of wet/dry over any of my waterstones.

 

[Spartan00]

I looked at the sigma stones . They seem to dish too fast for me ,I'd rather buy a belt for the sander .

Obsessed with edges, I agree with you. You haft to buy the right stones for the steels. When it comes to Waterstones this can be an expensive process ,especially if you don't have someone to help you out .

Personally I wouldn't buy another Waterstone for the purpose of sharpening say s90v,110v ,or 10v . They just don't cut it you figure how much a Waterstone cost vs the dishing your going to get from these supersteels.

I did sharpen 10v on some wet dry a few years back . I put it on top of leather .

IIT I started with 600 and by the time I was finished I had a mirror polish lol from the paper breaking down .

Also the spyderco bench stones do pretty well on an already sharp edge . Now I wouldn't touch a super steel to a spyderco ceramic unless it was 98% done .

Couple of light passes on a medium stone to clean it up is all I needed . The UF stone had little effect on it . UF is a great stone now probably my favorite stone I have . The fact is barely removes any material. That with a super steel unless you do a lot of passes it's not worth it IMHO.

 

[Spartan00]

Just to clarify I'm talking about s90v,s110v, and 10v . These 3 steels I've personally had trouble from waterstones .

Now zdp-189 I regularly sharpen on any stone I have . From kings to whatever it doesn't matter .

I've sharpened zdp-189, m4,m390, cruwear, pd1 hell I'm missing a few but I've had my share of supersteels and never had a problem .

10v especially is a different animal . Even s110v in my experience can be sharpened on my stones ,whether it was to its full potential or not it did put a sharp edge on it .

10v however will laugh at you . Now when the knife was new I'd do touch ups on these same stones and id get an edge back. I think now it had more of a sharpening steel or strop effect vs actually removing material .

 

[HeavyHanded]

Personally I wouldn't buy another Waterstone for the purpose of sharpening say s90v,110v ,or 10v . They just don't cut it you figure how much a Waterstone cost vs the dishing your going to get from these supersteels.

Another option if one has only a few tools made of super steels is to keep a couple sheets of 3M diamond lapping film around. They can do a great job on high VC steels when used over a hard surface and cost a fraction of what a diamond plate will run. Used carefully they can last a very long time.

I'm currently doing some workup on a honing compound that is a blend of my usual SiC and a healthy dose of diamond - intention is to bridge the gap between 800 ANSI SiC wet/dry and something comparable to 4k JWS. Its performing well and is liable to become standard issue with my Washboard kits.

 

[Jason B.]

10v is some serious steel, I've scratched it with other stones but it's only truly sharpened on diamonds. My Shapton Glass stones seem to do a little bit but leave me with an edge lacking a lot of sharpness. IMO, they are not up to be task.

That said, 10v is the only steel that I can't seem to sharpen on my Shaptons, the combination of extreme alloy content and high hardness seems almost stressful to the stones. I find it odd the 10v is so troublesome yet my S110V Native sharpens like butter on the SG stones.

My K2 gets sharpened on a Coarse DMT then stropped on 1 micron CBN. It seems to hold its edge forever unless you get into some serious work. I use my knives often but still have only taken my K2 to the stones a handful of times, stropping seems to keep it maintained for a solid month or two before I feel the need to refresh it on the diamond plate. By comparison, I'm usually visiting the stones 1 or 2 times a week for most other steels.

The biggest deciding factor in using diamond or waterstone is IMO the quality of the heat treatment. If the steel is brought to optimal hardness and the protocol of the heat treatment was strictly controlled then the formation of carbides and distribution of alloys elements is simply much better. As an example: S30V is one steel that seems incredibly difficult for knife makers to HT, there never seems to be two alike HT even from the same maker. I've sharpened some S30V on King waterstones while others have gone seemingly unphased with that same feel on diamond plates that the 10v yields.

I let the steel guide the way for the most part, I can usually gain enough feedback from the stones in a few passes to know what's going to work.

 

[Spartan00]

Jason I agree. My k2 hasn't really gotten dull on its own. I'll kill the edge just to play around with it . The thin grind and also I took mine to a belt sander and thinned it even more for quicker sharpening . It ain't pretty but she cuts like a demon.

That's what I was trying to describe about the stones . Some you can just tell if it's going to cut or not .

The cheaper stones (King mainly) seemed to almost burnish the edge like a UF spyderco does .

I've not had issues with any other steels either . S110v has even been polished on a cheapie Chinese 12k.

Best way I can describe it is say s30v and Arkansas stones is like 10v on regular Waterstones. Doesn't really sharpen it but it does polish kind of .

 

[Spartan00]

Another option if one has only a few tools made of super steels is to keep a couple sheets of 3M diamond lapping film around. They can do a great job on high VC steels when used over a hard surface and cost a fraction of what a diamond plate will run. Used carefully they can last a very long time.

I'm currently doing some workup on a honing compound that is a blend of my usual SiC and a healthy dose of diamond - intention is to bridge the gap between 800 ANSI SiC wet/dry and something comparable to 4k JWS. Its performing well and is liable to become standard issue with my Washboard kits.

Never underestimate a cinder block either . Seriously . Not sure about super steels though. Neighbor had a yard sale and we bought a bunch of kitchen knives made in Japan.

They weren't High end or anything but we're a lot better quality than your Wal mart specials.

None had an edge on them. Just for the fun of it I grabbed a cinder block, and a piece of another and lapped one the best I could .

Used a lot of water and I recut the bevels. It wasn't ideal but it got the job done . If you have a sidewalk or cinder block you can have a coarse stone lol.

 

[Wowbagger]

I don't strop my edges anymore because I like to test myself off of just the stones .

Bless you, just when I feared the last cab had left taking sanity with it

Well I got just one thing to say



Well you know I can’t say so little about anything.
hahaha

It came today. Went and picked it up in the rain from the post office before breakfast.
Addiction can make a person do strange, extreme, things. The stone above the Jende is the Shapton Edge Pro 500.

I have had a couple diamond plates for the Edge Pro in the shopping cart for a while now and have been waiting for the Jende 120 to show up first to find out if it is all I need or if I should get me some Edge Pro Diamond. First to see if it would show up at all, I haven’t ordered from this outfit before and it was coming all the way from Taiwan so I mean anything could happen. (just getting stuff across the pond from the UK has proved less than possible at times).

If I hadn’t read this thread I might have removed the diamond plates form the shopping cart.
As a result of this thread I now understand much better what the the diamond plates could do for me on my CPM-S110V.

As far as a different finish; yes I experienced that on the above alloy. The Edge Pro Shapton 500 when taken to the Spyderco Factory grind was much smoother bordering on a polish though it was cutting the steel fine and there was a lot of black coming off onto the stone. The edge was sharp in no time and some edge damage . . . flattening . . . (I don’t think I could call it chipping OR rolling but it looked like the edge had collided fairly lightly with a metal surface. I think I know when it happened. I was trimming some very hard rubber and may have gently over shot.

I stopped the grit "progression" there on advice from The Mighty Ankerson.
The edge would bite into my finder nail and cut very well after that sharpening. [I meant "finger" nail but it is kind of funny if you think about it so I left "finder nail".][well it's funny to ME anyway] . . .

although
I have only cut soft rubber, the tapered part off some plastic gallon jugs and a very, very small amount of cardboard (one or two slices) and the edge will not bite into my nail except near the choil where the edge remains unused.

If I didn’t know better (Spyderco quality and all really great) I would begin to question the heat treat on this here super blade.

Maybe I shouldn’t expect nail bite on this steel and this 500 Shapton edge; pretty shallow grind though. By nail bite I mean like this (different knife).



PS: Kind of encouraging, all this positive talk about diamond plates on the good-stuff-alloys. I carry this sharpening “Emergency” kit (mostly diamond paddles).


Just yesterday I saw a bad situation beginning to turn into a medical emergency. The boss had a 10mm bit all chucked up and was trying to force it through an aluminum plate. By the amount of trouble he was having I feared the drill was set on reverse but he’s pretty sharp that way (even if his tools aren’t).

Once he put his hand directly behind the exit axis of the drill and practically closed his eyes for that last bit of drilling Umpff I threw a penalty flag and stopped the play by asking if he would like me to sharpen that bit. I mean . . . he wasn’t even getting dust coming off the drilling location.

I took the extra coarse green paddle to the Cobalt bit and within a couple minutes I had edges that would “bite” my nail. I had to resist the practically irresistible compulsion to go on to the finer paddles and handed the bit back to him. I knew from past experience if I took one extra second to refine the edge he would practically have a stroke from the “extravagant waste of time”.

Once chucked up he was getting nice big leaves of aluminum coming off both edges of the bit (normally would have been two nice continuous ribbons but he must have been getting some kind of interrupted cut going on. I think he as trying to move a hole as well as enlarge it.

Super Sharpening Paddles saves the day and once again maintains civilization as we know it.

Normally I feel weird about using these diamond paddles and wish I were using the water stone slips but . . . maybe I am coming around to the finer points of diamond.
Pun intended.

 

[Spartan00]

Bless you, just when I feared the last cab had left taking sanity with it

Well I got just one thing to say



Well you know I can’t say so little about anything.
hahaha

It came today. Went and picked it up in the rain from the post office before breakfast.
Addiction can make a person do strange, extreme, things. The stone above the Jende is the Shapton Edge Pro 500.

I have had a couple diamond plates for the Edge Pro in the shopping cart for a while now and have been waiting for the Jende 120 to show up first to find out if it is all I need or if I should get me some Edge Pro Diamond. First to see if it would show up at all, I haven’t ordered from this outfit before and it was coming all the way from Taiwan so I mean anything could happen. (just getting stuff across the pond from the UK has proved less than possible at times).

If I hadn’t read this thread I might have removed the diamond plates form the shopping cart.
As a result of this thread I now understand much better what the the diamond plates could do for me on my CPM-S110V.

As far as a different finish; yes I experienced that on the above alloy. The Edge Pro Shapton 500 when taken to the Spyderco Factory grind was much smoother bordering on a polish though it was cutting the steel fine and there was a lot of black coming off onto the stone. The edge was sharp in no time and some edge damage . . . flattening . . . (I don’t think I could call it chipping OR rolling but it looked like the edge had collided fairly lightly with a metal surface. I think I know when it happened. I was trimming some very hard rubber and may have gently over shot.

I stopped the grit "progression" there on advice from The Mighty Ankerson.
The edge would bite into my finder nail and cut very well after that sharpening. [I meant "finger" nail but it is kind of funny if you think about it so I left "finder nail".][well it's funny to ME anyway] . . .

although
I have only cut soft rubber, the tapered part off some plastic gallon jugs and a very, very small amount of cardboard (one or two slices) and the edge will not bite into my nail except near the choil where the edge remains unused.

If I didn’t know better (Spyderco quality and all really great) I would begin to question the heat treat on this here super blade.

Maybe I shouldn’t expect nail bite on this steel and this 500 Shapton edge; pretty shallow grind though. By nail bite I mean like this (different knife).



PS: Kind of encouraging, all this positive talk about diamond plates on the good-stuff-alloys. I carry this sharpening “Emergency” kit (mostly diamond paddles).


Just yesterday I saw a bad situation beginning to turn into a medical emergency. The boss had a 10mm bit all chucked up and was trying to force it through an aluminum plate. By the amount of trouble he was having I feared the drill was set on reverse but he’s pretty sharp that way (even if his tools aren’t).

Once he put his hand directly behind the exit axis of the drill and practically closed his eyes for that last bit of drilling Umpff I threw a penalty flag and stopped the play by asking if he would like me to sharpen that bit. I mean . . . he wasn’t even getting dust coming off the drilling location.

I took the extra coarse green paddle to the Cobalt bit and within a couple minutes I had edges that would “bite” my nail. I had to resist the practically irresistible compulsion to go on to the finer paddles and handed the bit back to him. I knew from past experience if I took one extra second to refine the edge he would practically have a stroke from the “extravagant waste of time”.

Once chucked up he was getting nice big leaves of aluminum coming off both edges of the bit (normally would have been two nice continuous ribbons but he must have been getting some kind of interrupted cut going on. I think he as trying to move a hole as well as enlarge it.

Super Sharpening Paddles saves the day and once again maintains civilization as we know it.

Normally I feel weird about using these diamond paddles and wish I were using the water stone slips but . . . maybe I am coming around to the finer points of diamond.
Pun intended.

I completely destroyed a dmt 2x6 on an edge pro lol. It was my fault but still .

When I first got zdp-189 and some of the other steels they intimated me I'm not going to lie .

All these people saying they can't be sharpened or never let them get dull etc. So input the diamonds on the edge pro..

Diamonds can be your best friend or they can jack up a knife if you don't know what your doing . When learning to sharpen I ruined a few softer steel knives with an XC dmt .

I've had folks call me crazy for my loving of coarse stones but it's the most important stone in the sharpening process . That rare occasion you need a aroma 140 or a similar grit Waterston you'll be glad you bought it .

The most important thing is knowing what steels to use what abrasive with .

I've reprofiled vg-10,aus8 and other steels like this with a dmt fine plate . There was no need to go to a 220 grit diamond when the 600 did the job just fine and left me a great edge .

As far as stropping goes it's a personal thing , I keep my edges coarse mostly and stropping on leather too much just takes the bite out . Light passes and higher angles will break off any burr.

Also some more food for thought. Cliff stamp brought this to my attention but the more you strop an edge back say with black or white compounds the weaker that edge is (think bent foil and straightening it then bending then straightening )

Sometimes it's best to do what cliff calls destress, razor community calls it bread knife but it's killing the edge on the stone to cut a new one . It gets all that weak metal off .If you strop to maintain your edges too much between stones your edge retention suffers.

 

[HeavyHanded]

Also some more food for thought. Cliff stamp brought this to my attention but the more you strop an edge back say with black or white compounds the weaker that edge is (think bent foil and straightening it then bending then straightening )

Sometimes it's best to do what cliff calls destress, razor community calls it bread knife but it's killing the edge on the stone to cut a new one . It gets all that weak metal off .If you strop to maintain your edges too much between stones your edge retention suffers.

(in bold) Whaaat??!!

Stropping does not weaken an edge unless heavily done on something very hard like a waterstone. Under careful observation you will be able to see either the edge microfracturing along the apex, or more commonly it will fold slightly. If you don't see the edge shifting back and forth then it isn't shifting back and forth. Stropping on an abrasive is fundamentally no different from making a few super light passes at 30 and 40 on a Sharpmaker (or any other combination of finishing angles per a microbevel).

Stropping on a conformable surface dramatically reduces unit pressure of the individual abrasives, orders of magnitude less than running the edge on a hard stone or steel, let alone microbeveling where force relative to surface area goes through the ceiling. Yet these means do not inherently weaken or fold the edge back and forth unless too much pressure is used.

What kills retention relative to stropping is when the edge gets overly broad due to too much wrap of the strop or poor angle control over time. True, stropping on leather or other conformable surface will reduce irregularities and as such if one favors a toothier edge they should not strop or make sure to strop on a harder surface. This lack of material-catching irregularities is not necessarily desirable for EDU and can have an effect on edge longevity depending on application, but it isn't due to the edge weakening.

 

[Spartan00]

(in bold) Whaaat??!!

Stropping does not weaken an edge unless heavily done on something very hard like a waterstone. Under careful observation you will be able to see either the edge microfracturing along the apex, or more commonly it will fold slightly. If you don't see the edge shifting back and forth then it isn't shifting back and forth. Stropping on an abrasive is fundamentally no different from making a few super light passes at 30 and 40 on a Sharpmaker (or any other combination of finishing angles per a microbevel).

Stropping on a conformable surface dramatically reduces unit pressure of the individual abrasives, orders of magnitude less than running the edge on a hard stone or steel, let alone microbeveling where force relative to surface area goes through the ceiling. Yet these means do not inherently weaken or fold the edge back and forth unless too much pressure is used.

What kills retention relative to stropping is when the edge gets overly broad due to too much wrap of the strop or poor angle control over time. True, stropping on leather or other conformable surface will reduce irregularities and as such if one favors a toothier edge they should not strop or make sure to strop on a harder surface. This lack of material-catching irregularities is not necessarily desirable for EDU and can have an effect on edge longevity depending on application, but it isn't due to the edge weakening.

I'm talking about just for instance stopping on leather with black compound . I had a few Emersons I maintained by stopping alone for awhile . They'd start to get dull and I'd hit them on the leather .

After so long I noticed the knife dulled more quickly . Think about it you roll your edge I'm talking need a microscope here and you take a strop or butcher steel to straighten that edge back out . After doing this time after time after time it will never go back to original sharpness and the edge retention does seem to be effected . Now there could be something I'm missing .

Heavy-handed we've had a lot if discussions over the years and you've always helped me with my sharpening so your opinion means a lot to me . Have you not ever noticed though with stropping only for maintenance edge retention is effected ? Again if I'm missing something or another explanation I'm all for it . Don't take my comment as arguing , I consider you a friend here .

 

[Obsessed with Edges]

"the more you strop an edge back say with black or white compounds the weaker that edge is (think bent foil and straightening it then bending then straightening )

Sometimes it's best to do what cliff calls destress, razor community calls it bread knife but it's killing the edge on the stone to cut a new one . It gets all that weak metal off .If you strop to maintain your edges too much between stones your edge retention suffers. " (...)

I don't quite agree with those points, at least as they're specifically described above. Stropping on a softish substrate with aggressive compounds like black (usually SiC, sometime AlOx) or white (usually AlOx) poses a greater risk of overpolishing and rounding of the apex. Not really an edge-retention issue (that's more about the steel itself), nor a problem of creating a 'weak' edge. More an issue of just over-rounding or overpolishing, which can eventually take the 'bite' out of a crisp edge. I notice it more with black (SiC) compound especially, if the substrate is too soft or forgiving under the blade's edge. White compound ('white rouge' of AlOx, specifically) works very, very well on a very firm or hard strop of denim or linen over a hard backing; I maintained some of my edges for a very long while this way, and edge-retention never suffered for it. I've also had good results with black (SiC) compound when used very sparingly (minimal strokes) on a hanging-style strop; I use the rough side of an old leather belt this way, with the compound. It's easy to go too far with the black, though, and it can easily take the teeth off an even very coarse edge, very quickly; so, when I use it, I limit it's use to maybe 5 or fewer passes per side, with a very light and low-angle 'skimming' stroke to minimize any compression or rolling of the leather around the apex.

'Weak edges' result from thinning an edge too much without actually removing the very thin, weakened steel (wires, burrs) at the apex, or the repeated bending back & forth of burrs or wires at the edge, as on a bare strop or one with an inadequate compound which isn't effectively removing steel in the first place. I've never seen this issue with white or black compounds, as both are very, very aggressive at quickly removing such weakened metal at the apex, leaving a very clean and durable edge behind. In particular, both are very good at stripping away even very heavy, thick burrs on otherwise very ductile steels, like softish 420HC or VG-10, or ATS-34 (strongest, most tenacious burrs I've ever seen, even at relatively high hardness). Burr removal from such steels is what these compounds do best, in my own experiences with them.

I don't rely much on compounded strops at all anymore, if only because my edges coming off the stones are much less in need of stropping nowadays, save for perhaps a few strokes on bare leather (belt) or on my jeans. That said, I still wouldn't have any worries at all about a stropping-specific maintenance scheme with black & white compounds, so long as they're utilized optimally.


David

 

[Spartan00]

Obsessed with edges could very well be rounding it . I was more less talking about basically stropping taking the place of honing like say for instance instead of touching up an edge on a very fine grit stone you just strop and strop and you continue this for a long time .

Like I said there may be something I'm missing here I don't know everything and I've been wrong a lot . Other factors could of been at play to make me think the stropping was hurting edge retention.

It's just my way of thinking if an edge has microscopic burrs and dulling occurs by those burrs or serrations rolling to one side or the other and stropping straightens them out . It would seem like if done enough the metal you keep bending and straightening would become weaker .

 

[Obsessed with Edges]

Obsessed with edges could very well be rounding it . I was more less talking about basically stropping taking the place of honing like say for instance instead of touching up an edge on a very fine grit stone you just strop and strop and you continue this for a long time .

The problems created by stropping too much usually aren't about the compounds themselves, but more about technique issues or using a particular compound inappropriately for the situation or for the particular steel being stropped. Too much pressure on a soft backing, or too-high an angle would be the common technique issues; both of which would round off an edge. Going too far with an aggressive compound will create problems also, or using a relatively weak compound which doesn't cleanly cut or polish a high-wear steel would also bring troubles as well (attempting polishing with green compound on carbide-heavy steels, for example).

Like I said there may be something I'm missing here I don't know everything and I've been wrong a lot . Other factors could of been at play to make me think the stropping was hurting edge retention.

It's just my way of thinking if an edge has microscopic burrs and dulling occurs by those burrs or serrations rolling to one side or the other and stropping straightens them out . It would seem like if done enough the metal you keep bending and straightening would become weaker .

As described there, you're exactly right. That repeated bending back & forth of the burrs will weaken the junction between the burr and the stronger steel behind it. The burr may or may not break off; but if it does, there's a good chance some of that weakened steel will be left behind. That's where using an appropriately aggressive stropping compound can quickly (this is key) strip away the burrs via abrasion and without all that bending back & forth, leaving only strong & durable steel at the apex.


David

 

[HeavyHanded]

I'm talking about just for instance stopping on leather with black compound . I had a few Emersons I maintained by stopping alone for awhile . They'd start to get dull and I'd hit them on the leather .

After so long I noticed the knife dulled more quickly . Think about it you roll your edge I'm talking need a microscope here and you take a strop or butcher steel to straighten that edge back out . After doing this time after time after time it will never go back to original sharpness and the edge retention does seem to be effected . Now there could be something I'm missing .

Heavy-handed we've had a lot if discussions over the years and you've always helped me with my sharpening so your opinion means a lot to me . Have you not ever noticed though with stropping only for maintenance edge retention is effected ? Again if I'm missing something or another explanation I'm all for it . Don't take my comment as arguing , I consider you a friend here .

Its all good, not trying to toss any attitude as I consider you a buddy as well. But that assertion makes no sense. Consider the lateral forces on your edge as you make less than perfect cuts through something like pine, yet the edge isn't flopping all over the place - how much less likely from a swipe on leather even if you're leaning on it? Believe me, I have observed bonafide burnishing with plain paper over one of my Washboards - actual plastic flow albeit on a very small scale compared to using a meatpacker's steel or similar, but present for sure. Is one of the cooler things it can do.

The apex isn't flopping around. Not too long ago I did an experiment to see how long I could maintain Aus8 using only paper on a Washboard and was amazed the time between needing refreshing went up, not down, over a period of several weeks. Finally did need to be corrected, but keeping in mind this was plain paper and not a loaded strop. If the edge were shifting side to side it would have failed almost immediately.

I've noticed if I used a conformable strop to maintain the edge over a longer time frame, retention goes down as you're compounding the wear bevel with more microrounding and at the apex the terminal angle gets huge, though not necessarily to the naked eye. The edge might get sharp again, but at a slowly increasing angle. It cannot keep up with the wear bevel.

Under 100, 400, 1000x these things jump right out.

If the strop is hard enough then you remove steel behind the edge as you go and all the pressure isn't spiking right along the edge as the strop expands back to its original volume. Likewise with super light pressure on a softer strop, but then the amount of steel removed (and by extension ability to overcome dulling) goes way down.


If you backhone on a softer waterstone carefully you will see a huge increase in retention relative to softer media, all thing being equal. Over time the edge might still round, but only due to operator error and opening the edge up beyond what a polishing grade stone can repair (same functionally as what happens on a softer strop). The difference is that the harder media can remove steel behind the edge and true it up a bit. This is also true of harder stropping surfaces. With good technique on a harder strop, edge wear might never reach a level where a stone is needed again short of major damage.


In the end its all relative to how hard the strop is. I've kept edges in top shape for long periods of time on a harder strop, only going back to the stones out of habit. And this includes plenty of use between. You know if your strop is good and hard by how much effort it takes to true the edge up on a hard stone again. If you're raising a burr with a small number of passes you know that edge isn't rounding over much.

And again, I haven't noticed any difference in longevity as long as edge finish is taken into account. Once you get into the brighter finishes no matter how they're made you'll see some longevity drop off if using for EDU. If the finish is matched to the task I've yet to note any real difference. If anything, when it comes to hard chopping I'd swear my hard-stropped edges hold up better than stone finished ones.


That isn't to say some folk might not be a whole lot better at some technique than others, but once you understand why things are happening, then you can work on how to control the results. So yes, some people might observe that long term stropping causes retention to drop off, and then to assume the edge is weakening somehow. But this is an assumption based on too few inputs IMHO - it has nothing to do with the edge weakening over time. Overly broad apex is a primary killer of retention, however it is formed.

There isn't even a consensus on whether the apex needs or should be destressed prior to sharpening. IIRC Brent Beach recommends only going to just shy of the apex when using coarse abrasives to avoid subsurface damage to the lattice - only working the apex with polishing grade abrasives for max longevity.

If stropping takes life off your edge, then don't do it except as experiment to learn exactly what's happening. After a while, you might find there are instances where you see an advantage.