Mirror'd edge, why bother?

[miso2]

My pleasure!

Miso

 

[Phixt]

Well I sure am glad I read all this. Thanks to all the contributors.

 

[Jake_Lucas]

Reignited my interest in the topic, thanks! Nothing says more than those microscope images

 

[Lapedog]

Lapedog, I would not order a high grit stone of any type grit. As I don't shoot for a high finish in my sharpening for daily cutting needs. I mostly strive for a general cutting edge. 3-400 grit. As I mostly cut apples, rope, cardboard, ect.. I don't work long on the edge. When it dulls I can
quickly bring it back to sharp by stropping. When this can no longer be achieved I take it back to a 300 grit stone for a touch up. I have a high grit Spyderco
ultra fine ceramic stone and rarely use it. DM

I usually just go up to the fine sharpmaker stone. Although I do a few passes on the ultrafine just because I think it helps knock the burr off. The majority of the work is on the medium grits. I have absolutely zero luck with the sharpmaker diamond rods. The edge just seems to bounce off the peaks of the grit.

 

[Securis]

Clean edges cut better and are easier to restore and maintain, at any finish.

What would you determine to make the edge "clean". Is it to finish lightly on a significantly high grit stone after putting on a course finish? or is there a specific method to clean an edge on any said finish.

I've actually started an experiment on M390, Bencmade mini barrage. I've done the test for the course finish, 2000 grit diamond. I will be performing the test for fine finish in the next few days. I had the knife sharpened yesterday, but saw a flatspot, so i'll have to redo it.

 

[HeavyHanded]

What would you determine to make the edge "clean". Is it to finish lightly on a significantly high grit stone after putting on a course finish? or is there a specific method to clean an edge on any said finish.

I've actually started an experiment on M390, Bencmade mini barrage. I've done the test for the course finish, 2000 grit diamond. I will be performing the test for fine finish in the next few days. I had the knife sharpened yesterday, but saw a flatspot, so i'll have to redo it.

In this context I'm referring to burr free and none or very little of the localized swaying back and forth off the line that some of his images show. It would be pretty much impossible to tell if the swaying is mostly gone without a SEM, but burr cleanup is a different story.

 

[on_the_edge]

I've always thought non leather workers over estimate the protection to being cut or stabbed that leather affords. Once an edge or point is sufficiently sharp it cuts leather VERY easily.
People who make knives some times wear leather aprons thinking this will protect them if a machine flings the blade back at them. Nope. Only chain mail.

Interesting discussion here for sure. In re the above, isn't there a difference between cutting leather (or any medium for that matter) and simply puncturing it with a tip? I'm asking because you mentioned "protection to being cut or stabbed" and I always thought those two things were not necessarily related. I might be going to far afield here, but if you look at something like kevlar, it can stop some bullets from penetrating, but the pointy tip of a knife is will supposedly penetrate with surprising ease. Yet does that mean that a sharp edge will cut it easily as well? I do not know the answer. I do know that a few years back, a knifemaker died when a knife he was grinding/sharpening flew out of his hand and lodged in his chest. I don't remember who it was or if he had any chest protective gear on, but I sometimes wonder if it would have made a difference given how sharp our knives can sometimes be.

 

[Jason B.]

I was into polished edges for a bit and thought they were great, then I was part of some CATRA testing and watched them fail miserably against the coarse edge. In truth it's not that they made that many less cuts it's just they had a dramatic fall off of edge sharpness whereas the coarse edge held a higher level of sharpness.

Analogy would be to compare an alkaline battery to a lithium battery. The alkaline falls off steadily where the lithium holds a consistent level until the very end where it's abruptly stops working. Alkaline being the polished edge and the lithium being the coarse edge.

And as always, the intended task can change the need for one edge type or the other.

 

[Wowbagger]

Interesting discussion here for sure. In re the above, isn't there a difference between cutting leather (or any medium for that matter) and simply puncturing it with a tip? I'm asking because you mentioned "protection to being cut or stabbed" and I always thought those two things were not necessarily related. I might be going to far afield here, but if you look at something like kevlar, it can stop some bullets from penetrating, but the pointy tip of a knife is will supposedly penetrate with surprising ease. Yet does that mean that a sharp edge will cut it easily as well? I do not know the answer. I do know that a few years back, a knifemaker died when a knife he was grinding/sharpening flew out of his hand and lodged in his chest. I don't remember who it was or if he had any chest protective gear on, but I sometimes wonder if it would have made a difference given how sharp our knives can sometimes be.

If you like to ponder puncturing power of the point be sure to check this out if you haven't already :

 

[Kai Winters]

Because I like a mirror edge on a couple of my folders. The rest are "work" knives and just get a good working edge.

 

[Securis]

Interesting discussion here for sure. In re the above, isn't there a difference between cutting leather (or any medium for that matter) and simply puncturing it with a tip? I'm asking because you mentioned "protection to being cut or stabbed" and I always thought those two things were not necessarily related. I might be going to far afield here, but if you look at something like kevlar, it can stop some bullets from penetrating, but the pointy tip of a knife is will supposedly penetrate with surprising ease. Yet does that mean that a sharp edge will cut it easily as well? I do not know the answer. I do know that a few years back, a knifemaker died when a knife he was grinding/sharpening flew out of his hand and lodged in his chest. I don't remember who it was or if he had any chest protective gear on, but I sometimes wonder if it would have made a difference given how sharp our knives can sometimes be.

That's a rough way to go man. I thought it was a rule of thumb to have the blade grind away from the user.

 

[Wowbagger]

That's a rough way to go man. I thought it was a rule of thumb to have the blade grind away from the user.

I have not had it happen to me and perhaps I am over reacting but all it takes is letting the mind wander, especially if one has had a bad day or a disagreement with some one, and snag the tip on a belt or buff and FLIP !
Hard to tell which way it is going to go or where it is going to come to rest.

I didn't watch this vid, I just saw the opening frame on YouTube but look at the sparks flying back at the operator. The knife would follow the same path if there was an anomaly. Like I said maybe I am over reacting.

I grind mine on bench grinders and the white slow water bath wheel shown bellow but I'm just fooling around and not trying to make a living at it. (I have a basic table top belt sander but . . . nah dude, nah.)


And lets not forget the super coarse diamond file. It did this and that is CTS-XHP (pretty hard and tough alloy and already hardened).