Thread: What Does it Mean, Taking an Edge too Far?

What Does it Mean, Taking an Edge too Far?

I admit, the 2nd shave on a newly honed blade seems better to me but I always thought that was the result of my lack of skill.

--james

homing...honing..and re honing some more..when the edge is perfectly capable..removal of excess steel IMO

Originally Posted by smalltank

homing...honing..and re honing some more..when the edge is perfectly capable..removal of excess steel IMO

Thanks. That makes complete sense to me.

To me it means that the edge is honed to an extreme beyond what the steel is able to hold.
In other words, the very apex of the edge gets too thin, and the steel simply will not be strong enough for it.
From what I remember, gssixgun has posted some number on at what level of micron thinness that happens, but i can't seem to remember what it was right now.

The critical issue with edge holding is angle and not polish. If a steel isn't hard enough for a very acute bevel angle, the edge will fail. But higher polish actually makes it more durable, the edge is more evenly and fully supported in all directions at a perfect polish.

I think "taking an edge too far" means different things to different people. I would call it a superfine honing of an edge, without any softness to the edge, where it's almost impossible to shave without weepers and the resulting razor burn that comes later in the day or the next day.

My answer is coming from my experiences sharpening KNIVES. I have also honed a few razors, but I have never taken them too far in my understanding of what this means.

1. Too far could mean removal of more steel than is necessary. How "necessary" is defined is a sticky topic...particularly with show knives. Some want to do whatever is necessary to make a VERY uniform and symmetrical bevel. It is possible to achieve high levels of sharpness with very odd looking bevels.

2. Too far (IMO) means refining an edge to levels beyond what is practical and sustainable by the steel and the geometry of the blade for its intended uses. This I have a lot of experience with in the knife world. I have had people request a pocket knife to be profiled at a certain angle, then have the bevels polished to a mirror finish, and the result needs to be HHT3 or better. While it is certainly possible for almost any steel available today on quality knives, I know of very few that will sustain this level of sharpness beyond a few basic cuts you might expect a pocket knife to perform (such as opening mail).

Razors have a MUCH narrower scope of work, but I would suggest that they can be taken too far also (by the second definition). I doubt that it is done often, but I suspect (without any evidence or data) that extensive stropping to finish a razor on compounds in the 600K range would fit my definition. Opinions probably vary

Thanks to everyone who responded so far. I have learned a lot.

--james

The term and it's brother "Over Honed" have been so mis-used that thay no longer mean anything...

To put it as simply as possible,,, I'll give you some numbers (not mine)

The edge will start to slice through hair at about .50 Microns (we do that at 1k) and depending on the the Grind, Geometry and Steel a Straight razor can get down to about .38 Microns.. that's it, period you get to mess with about .12 Microns of metal between 1k and whatever K

As one person has put it on here "I can hone just fine, knowing when to stop is my problem" I always liked that saying

Like Birnando said, reaching that limit is where the edge can become fagile and begin to fail, once it fails no big deal you just smooth it up and start again.. The problem edge is where you don't realize that the Fin is in that condition and keep using it... the edge literally begins to drops microscopic slivers of steel and becomes so ragged that the strop can no longer straighten the Fin any longer...


There is a balance point you want to bump against it but not go over it...


There is also the problem of each persons face with this, some people think that a Over-honed edge is any harsh shaver, but technically that isn't quite true either,, Just because your face can't handle a Extra hollow grind sharpened at 30k and stropped with .25 Diamond does NOT mean there is a problem with the edge it just means that type of edge is not for your face and perhaps your shaving skill at the moment... The edge could be fine and well within it's limit, it just might not be within your limit...

It doesn't matter how much honing one does. If you maintain the proper angle, more steel will be removed but the edge will not get too fine. I'm against removing too much steel as anyone, but if the same angle is maintained the edge will not get too fine and fail to hold.

Originally Posted by gssixgun

"Over Honed" ...

It is, to me, a term that is used to describe finishing with a sub-finishing stone, where the intention is to stop just short of removing the edge of the razor.

I don't know anyone who actually does it. It's been completely hijacked by folks thinking that they can overhone with green chromium and 0.1 micron diamonds, etc.

As far as an edge being weak because it's too sharp, if an edge is cleanly stropped and the particles that may exist from a stroke where the edge leads the spine are gone, I don't think there is any case where the edge would be weaker. This has already been proven in woodworking, where the same notion used to exist, that an edge too sharp was weak.

For a super sharp edge, as hairs bash the keenness away, maybe there is a sense of relative weakness, but an edge that is properly honed to 1/20th of a micron and stropped the same way as one that is less sharp initially will always be sharper on any given day vs. the one that started less keen.

The effect of the relative difference, though, makes people think the original edge was weak, when in reality the second edge for comparison was always more blunt and just didn't seem to change much because it wasn't that sharp to begin with.

Woodworking with a smoothing plane shaving creates wear much faster, but the effect is similar. There is an initial sensation that keenness is lost in the first few dozen or hundred strokes, but in reality the edge ultimately wears longer than the "strong" edge (that was less keen) and on any given stroke of the plane at any count, is also sharper than the edge that was less keen to start.

Before we can talk about edge weakness, we need to have a relative comparison of a same spec razor that starts out at a duller point. At no instance will the razor that started out sharper cross into being duller than the one that started less sharp.