Thread: What exactly is overhoning?

Originally Posted by JimmyHAD

No need to destroy it. Randy told me that if you have an overhoned edge take a wooden match stick and weight of the blade run the edge across it. If you're lucky stropping will bring it back if you're not back to the hone. Back honing a few strokes can also get rid of a burr.

I meant destroy it by grinding the heck out of it. I am gonna overhone a razor or grind it down to 1/8 trying!

Originally Posted by JimmyHAD

I think there is also the phenomenon of finishing a razor to an optimum sharpness but going on and losing it.

That's what I was thinking of in reference to the high grits. It didn't happen to me, but there are a couple of possible reasons why:
1. I've only tried it with a Naniwa 12k. It's possible that it's high-lap friendly.
2. Maybe I passed optimum sharpness, and ended up with something that while really sharp isn't quite as good as it could be.
3. I didn't test sharpness as I progressed through all those laps. It is possible that the edge becomes "unsharp" but then becomes sharp again as more laps are done.
(more experimenting is required)

Originally Posted by JimmyHAD

It is a delicate balance for me. Seems like a lot of guys take to this honing like a duck to water. I've had to work at it but maybe I'm slow.

Your modesty is unrivaled.

Originally Posted by HNSB

In progress....
That was part of the idea of this thread - to find out what it takes.
I am up to four razors now with the same progression mentioned in the OP, and I've gotten nothing but smooth shave-ready edges.

I guess I didn't try overhoning on the low end, and I didn't use any pressure. Those are things I am going to try as well. For some reason I had it in my mind that I read overhoning is easier on the high grit stones. But, maybe it is more a thing on the low grit stones. The general consensus seems to be that when it happens, it is the result of forming a burr on a low grit.

I just need to find a razor that I don't mind destroying in an effort to understand this.

You can "overhone" on high grits but normally it is called Microchipping, I personally don't look at that quite the same.. That is the only type of "overhoning" I have seen without applying pressure..

If you think about the very very fine edge The "fin" being flexed and then the honing going on just behind it, instead of on it, That might help you wrap or mind around the concept...

I wish I could do those cool graphics to show what I mean, but basically you are honing away the support behind the edge and then it falls apart ... That is a huge over simplification

Originally Posted by ace

I'm not clear on why additional strokes once the bevel is set would "decrease the width" of a blade.

Please let me draw you a really lame picture.

The angles remain exactly the same, yet you are removing material, so it must get smaller. The spine will get narrower, and the overall blade width from spine to edge will as well.



Obviously, you would have to spend all day, or use an insanely coarse stone to accomplish what that picture illustrates, but I have seen ebay and antique store razors that were used for a lifetime and regularly honed that started out at 5/8 hollow or half hollow blades, and ended up as 3/8 wedges.

Also, that image shows a triangle MUCH shorter and wider than a cross-section of a typical straight. with the taller/narrower cross section of most straights, the effect would be even greater, but harder to draw a picture of in less than 60 seconds.

Steve,

Thanks for the picture and nice explanation. Would that hold true if the spine had been taped, eliminating the wear there?

To eliminate wear you have to tape the spine and the edge. Advanced honing technique known to few and practiced by fewer.

Originally Posted by HNSB

For some reason I had it in my mind that I read overhoning is easier on the high grit stones.

I sometimes overhone on the low grit but that's because I do the things that are conductive to overhoning. Since I usually want to hone out chips, I use fast hone, pressure, and multiple passes on one side, then multiple passes on the other. If you overdo it a lot you can see the burr with a naked eye from light reflection, but since I check the edge every now and then in the microscope I can see it forming way before that point. I don't really care much about it, since it's usually just 1/256" and the only result is that it takes a little longer to hone out the jagged edge on the next hone (4k-5k level).

On the finishing hones think I've gotten a burr just once (and it's really tiny one, almost invisible in my microscope, but more than enough to screw up the cutting), just by the virtue of the type of honing done at that point - very light strokes and only a few of them (after all if you need to do a lot of honing it means you haven't done your job on the previous levels).

Now I've gotten microchipping because the steel cannot support a finer edge, many more times, and that's because I'm pushing the limits of the razor. Once it happens I know where to stop when I redo it.

After working on my razors and thinking I was starting to fell like I was getting better all this has made me realize that I dont know squat. Thank you gssixgun for the explanation on microchipping as that made somthing click and I understand what you are talking about. I had concerns about overhoning also but was told I need to worry more about underhonig. I guess figureing out when you have gotten all from one stone and moving to the next before going to far is the thing and its going take more than 2 razors for that one. Mabey after 100 or so. I cant wrap my head around thousands of razors yet but even the men who have honed that many had to start on number 1 to so I have hope. Thanks for continuing to talk on this, its very interesting and helpfull to us noobs.
Glenn

Originally Posted by JimmyHAD

To eliminate wear you have to tape the spine and the edge. Advanced honing technique known to few and practiced by fewer.

Jimmy, you werent supposed to tell!

Originally Posted by ace

Steve,

Thanks for the picture and nice explanation. Would that hold true if the spine had been taped, eliminating the wear there?

Nope, as Jimmy pointed out, you'd have to tape the edge too.

Let me give a little disclaimer here....

This is not a reason to tape the spine when honing, OR a reason to not tape the spine. It's just a fact of geometry. No more, no less. The tape or no-tape issue has been debated so much you can't even tell that the dead thing people are kicking used to be a horse anymore.


Now, that said, not only does taping the spine not prevent the blade from getting narrower over time, but it changes the geometry of the blade just slightly each time as you can see in this equally lame sketch.



With each honing, the actual angle of the edge becomes less and less acute. Once again, the effect is VERY gradual, and you would never see a difference after each honing. Plus, once the difference eventually became enough that it caused a problem, there is no reason the spine couldn't be reground.

It's also worth pointing out that if you're doing it right, and only removing as much steel as you absolutely need to remove, it would take dozens and dozens of honings on the same razor to make any meaningful difference whether we're talking about geometry changes OR reduced blade width. It certainly does happen over time, but it's so gradual that it's really not an issue in practical terms. On top of all that, you can also gradually chage the geometry of the razor just by being less than skilled at honing. If you apply more pressure to the edge than the spine or vice versa, you can do more damage in one honing session than a dozen trips to a good honemeister

Ace nailed it in post #13. Over honing does not exist. Bad honing technique and not knowing what you are doing on the other hand DOES exist. Case closed.