Thread: overhoning

I have heard very vague descriptions : It's when the edge breaks down. A given natural won't do it; but a fast cutting synthetic is sure to.

The honing angle is set, the hone abrades right at the very very very edge until it turns up the tiniest bur (+1) you turn the razor and cut away the bur(-1) continuing along the stone until at the end of the stroke you have turned up the tiniest bur.

So if all was perfect like how i does it you hit the zero again and again. Over honing by going back and forth.

Which makes the point again from the HM's in my other thread. using just the right pressure. Too light and the bur might become exaggerated as the "0" edge floats up a little, honing happens behind the 0 thinning elongating the bur- very fragile construction.

Too much and you are flexing the actual factual part of the razor turning up a monster bur you can rip off.

just right and you force the bur into a tight curve that continually rezeroz itself.

This is a question. Thoughts?

I think that a wire edge isn't much of a problem, with regular testing and light finishing strokes.

I've tried to make one on purpose several times, using light pressure, without success. I have made one using relatively heavy pressure and continually honing the same side (more like a burr..?).

If you do get one: the ones I made on purpose were very easy to wipe off. I have had crumbling on several old vintage razors, but I believe it was oxidized steel instead of overhoning.

I have found it happens easily on some razors, like Wapis, and not others. I see it very, very rarely. Maybe the steel is a factor? When I sharpened carpenters tools it nearly always happened - the guy who taught me said it was desirable. (I do appreciate that chisels, knives and so on aren't in the same league of sharpness as razors, before the deluge begins!).

Regards,
Neil.

It is good for chisels etc when the bur is cut off on the finest finish hone. (whatever the back is polished with)

If my description is correct then to me over honing means honing too much-taking away more than necessary.

If the honing is not precise enough then remnants of the bur could remain. burs turning from both sides perhaps.
if the honing is precise then one should never get a wire edge when honing flip flop style

But, from your desription you aren't honing at the very tip - if the bevel is set, then all the plane in line with the bevel is hitting the hone at the same time - or have I got it wrong? If it's the "...very, very edge..." then the angle must have increased to lift the bevel plane off the hone - mustn't it? I know some woodworkers slightly increase the angle to remove the burr, but maybe I'm reading your description wrong.

From what I've read the formation of a burr is an indication that the tool has been sharpened sufficiently. Harder steels produce less of a burr, finer stones produce less of a burr. I'd like to know what induces the burr to stay bonded to the edge, too. I understand that honing past the formation of the edge produces a burr, but the formation of that edge must occur at a point that is not discernable within strict limitations.

In other words, how do you know that enough is enough? It's all very well saying that if honing is precise you won't get a burr, but what if one stroke past optimal results in the beginning of burr formation? Who can be that precise? Maybe billion-dollar-man eyeballs would help! I only test every 10 - 15 round laps. If you can see a burr, it must be way too much (for razors) and if you can feel it on your thumbnail it must be too much, but when did it begin?

If a micro-burr is present, how do you remove it? And is it necessary or even desirable to remove it? Is that microscopically thin cutting edge on a razor, sometimes termed a fin, in reality a form of micro-burr? Perhaps that is all stropping is - burr removal. I've seen carpenters strop chisels on their pant legs to remove the burr - from there to a leather strop isn't such a big leap. But maybe stropping isn't burr removal at all, but merely burr realignment? Many sources say that the fin is deformed by shaving, and that the purpose of the strop is realignment, or correction, of that fin. If the terms "burr" and "fin" are one and the same, than that means the burr is desirable - at a microscopic level - to enable the razor to shave properly. In which case the whole purpose of honing is to raise that microscopic burr.

It's an interesting question...!

Regards,
Neil

I've never gotten a wire edge with good razor steel. Make sure you use light strokes, though. I would NOT personally use a razor that has a tendency to form a wire edge. Fortunately, with my razors, I can't get a wire edge even if I tried to get one on purpose.

You have some very good points Neil. Yes you would be honing the plane of the bevel, but the plane extends all the way to the edge, so when moving edge first that is the first stuff to swarf- it just means the bevel is set and the width is being cut down.

with precision the full length of bur would be formed and cut off, then reformed. for simplicity I said it all occurred in one stroke. If less than precise; portions of the bur could remain, finally resulting in a mixed up edge of burs curling this way and that. maybe it's the hones out of plane or the honer's stroke is off(?)

My goal is to understand what is this thing called overhoning. As I said: if you are using ideal pressure and cutting metal from the edge you are turning a bur. Flipping for the next pass removes the bur and turns another. Any given grit hone is then cutting as close to a zero edge dimension as possible.

It should never be able to grow very large unless you stay on one side as Sticky did on purpose. Or perhaps as I suggest one is using too light a pressure, such could be physically impossible I suppose.

I am talking about both types at the same time as I assume they behave the same. Which also means that I am saying you should never have one, but it is always there the fin bur is not desirable but is the nature of the beast.

Cotdt- that is the point exactly you can't get a wire even if you try. Or you tried too hard with a poor steeled razor

Thanks Kevin! I just came across an interesting post on the Badger & Blade site by the president of the Spyderco (of hone and knife sharpening fame) which I reproduce here:

Originally Posted by SalGlesser
Hi AussieMark,

While I appreciate the suggestion, I'm not sure it's a direction in which Spyderco could be successful.

The number of people that actually shave with a straight razor is very small. When I shaved with a straight razor (for about 5 years 15 years ago), I learned a fair amount about razor steels. I would recommend it for any knife afi. Great adventure.

I acutally made and shaved with knife steels. (D2, MBS-26). I found that the dedicated razor steels worked better for me because they created a "better" burr for shaving.

I'm not convined that harder steels will actually shave better.

The stropping is what creates the burr. When the razor begins to perform less effectively, one goes back to the strop, not the stone. I don't think I sharpened the razor more than twice a year, but stropped each day.

As far as the collector market for custom straight razors, I must say I'm clueless. I guess we can see what response we get here.

sal

The original is here.


Another source that stresses the importance of the fin is the Dovo web archive, para. 5:

]DOVO straight razors are whetted in the factory for use (whetting on leather by hand). If you own a suitable strop, you should nevertheless take into account that the razor must first "rest" after use. After the razor has been carefully rinsed and dried, it should not be used again for at least 24 - 48 hours because the fine "fin" on the cutting edge straightens up again extremely slowly. If the razor is stropped too soon (or stropped incorrectly by moving it backwards and forwards without turning it over), the "fin" which is necessary for a close shave breaks off. Between six and fifteen shaves are possible without stropping in between.

However, just as many other articles take the opposite stance - strropping is to remove the burr. Here's one by Dave Richey:

"...Years ago, in what seems a different lifetime, I was a barber. My late twin brother George was a barber, my 94-year-old father was a barber, and my father’s father was a barber. I have some experience sharpening a straight razor, and many of the same principles apply when sharpening broadheads.

Barbers, once they’ve sharpened their razor (seldom used these days), would use a canvas and leather razor strop to finish off the sharpening process. [...] As metal is removed by the honing process, a burr or rounded metal forms on the [...] razor edge. Stropping [...] removes that burr..."

Seems like you pay your money and take your choice!

Regards,
Neil

Kevin I am really glad you brought this up...
Let's really explore the overhoning issue here...
I said it in other threads many times, but I'll say it here again Overhoning is not all that easy to achieve, certain razors are what I refer to as "chippy" and will get a ragged edge more than others, Wackers come to mind, they are very temperamental, is this actually overhoned?? I don't believe so, I think it is more mis-honed.... Wapis are another that come to mind, another type of steel that lends itself to an "overhoned" condition, that I personally feel, is more of a heat treat issue, then actual overhoning, some Wapis have spots on the edge, that just fall apart....Basically each type of razor steel has a honing combination that will get it to shaving sharp, you just have to figure that combination out...
I have yet to receive a razor from a member here, that won't shave, to be honed, that is actually "overhoned", yet almost every thread, that the poster states "My razor is tugging when I try the shave" somebody will answer "It's overhoned" every single one that I have been asked to hone has been under honed and the bevel was not set properly to begin with...
I have managed to "overhone one razor so far, and that was on purpose, I used heavy pressure and circles to pull the heel on a badly warped W&B into line, on a Norton 220... Even in this extreme case, four back stokes cleaned it right up...
Basically my stance is that you have to really try to overhone a razor, now I will qualify that by saying, if you have any idea of what you are doing on the stones.... Because heavy pressure could do it...

That's my 2 pennies