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
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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
Quote:
Originally Posted by smalltank
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 :D
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.
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.Quote:
Originally Posted by gssixgun
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.
What prompted me to ask initially is that the 2nd shave after honing always seems better to me than the first. That was often the case too in the past when I used shavettes.
--james
Just don't do it man. I did once....
Now I am a broken man. I lost my family, my job, my soul. Now I wander the the earth searching for that perfect edge high.
Perhaps somebody that actually knows how to hone, Straight Razors, and how to take good High Mag pics can just do it :(
Are we talking about optical pictures? I don't think optical pictures will do the trick, there isn't enough resolution to see what's going on at the edge.
It's an easier test to just take two razors, sharpen one to the point that it's "overdone", and another one thats "perfectly done", and shave with both of them alternating days, properly stropping them with a bare strop.
As long as you can tolerate the first few shaves of the razor that's taken "too far". Maybe a test for someone who doesn't have sensitive skin.
It's pretty easy to prove, though proper stropping will make it so that it takes 2-4 months before both razors are pulling, maybe longer.
Let me take things back to the basics of Straight Razor honing,,, Straight Razors can get weak and fraglie edges because some (read above) "Grinds" actually allow the edge to "Flex" this allows the "Grit" to cut into the "Bevel" behind the Fin when too much pressure or to many laps are used, which can create "Fagile" edges
This can also be refered to as "Over-honing" or taking the "Edge to far" when talking about "Straight Razors" The "Terms" are very misleading (read above) as they have been tossed around so much in so many sharpening circles as to be somewhat useless now...
To the OP your probably stropping the edge in better as you procede, proper stropping will change the feel of the edge
Personally I prefer the term "Mis-Honed" because it actually is honed incorrectly regardless of why..That way we can figure out what was done and where the problem actually is within the honing process..
Several years ago on SRP the term Overhoned was tossed out near every time somebody said their razor wasn't shaving right.. It took many tests and tons of "Discussions" to change that, but it is possible to do just not as easy as many thought...
The term mis-honed seems much more appropriate. I am having trouble finding a historical discussion of overhoning, other than for a description of some older fine natural stones to be immune from "overhoning", presumably because they will create a quality edge even with their scratches all of the way to the very edge of a razor.
I have (not being a big frequenter of the forums until last year) never heard the term overhoned used for anything other than overshooting an edge, as the historical information that I've seen suggests that shavers never completely remove an edge. With a good enough (fine enough) stone, that's never a problem unless someone has poor technique or "mis hones" altering geometry.
Until today, I've never seen it used to describe improperly honing due to too much pressure (but that may be a product of tuning out most of the posts that have the word "overhoned" in the first place, especially in the era of cheap very fine abrasives that create nearly no foreign particles that need to be removed from an edge by anything other than light pressure on bare leather.
Maybe coming from a woodworking background causes a problem, i had assumed that anyone thinking at all about razors would understand that you can't flex them with a lot of pressure and expect a fine hone that barely does more than burnishing to actually get to the edge.
And FTR, the problems with sharpening appear in spades in woodworking, too. I have bought a LOT of used tools from people that were supposedly in use (think gouges and scrapers, I know you've done gun work), I have had exactly 1 that was properly honed. It's not that hard.
* set the geometry based on appropriate guidelines (obviously different for most knives, but for dogs and cats sake, the razor has the angle built into it)
* preserve the geometry while removing scratches
* make sure finest step actually gets all of the way to the edge and completely removes coarseness remaining at edge from prior steps
* rub on leather to remove anything undesirable that is hanging on the edge, and create smooth even wear/pushing/burnishing of the metal right at the edge.
I probably should never read any of these sharpening threads. So far, it's created discussions where I thought there was a difference in principle, but it really was only a difference in terms. And, seeded my brain with false notions of magical escher power or supreme keenness and softness at the same time, etc (the softness is there, keenness can be had elsewhere).
There are so many videos and discussions of sharpening now that I don't know how a beginner can't figure it out, unless they come here first and skip all of that.
(i still would like to see actual SEM pictures of the *edge* of the razor, and not the bevel - before and after stropping. Are there any of those?)
Thanks for this, Glen. This is the first time it has sunk into my head what some mean about a "weak overhoned edge".Quote:
Originally Posted by gssixgun
It makes perfect sense to me now...basically the blade flexes and allows the shoulder of the edge bevel to be cut with the net result of the thickness of the blade behind the edge getting ground away.
Am I correct that it would not be possible to achieve this result with any duration of honing as long as proper pressure is used?
Further it seems that this could result during any step of the honing process (i.e. on the 1000, or any other hone).
Thanks again.
I'll pull this image if I have it wrong, but are the bottom two illustrations what you mean? As in the green material in the bottom is ground away and no longer supports the apex?http://img.tapatalk.com/d/12/09/19/gava4adu.jpg
Yes but that is over simplified :)
Yes at any grit, but as stated in the first post it is very easy to correct,as you switch grits,, This is what the 4/8 pryamid was actually designed to eliminate,, By switching the grits and sneaking up on the edge you eliminate the "overhoning aspect" you are polishing and sharpening at the same time..
Using Slurry probably accomplishes that exact same thing, from the minute dulling effect of the slurry then the sharpening effect as you thin it out (Not Proved)
The basic geometry and sharpening require for Straight Razors as Dave pointed out should be rather straight forward, (pun intended) you do have a built in angle, so basically you push the edge across an abrasive and voila' a sharp edge.. BUT it just doesn't seem to work like that, there are other things coming into play, one is the pressure and another is the smooth part and to a lesser extent the shape of the edge (smiling blades change things)..
The simpliest honing is actually a heavy near wedge -IF- the geometry is right they do simply hone as you would expect, unfortunatly the geometry is rarely right so they become bears to hone :(
When I first joined SRP (please go look) most every honing issue in this forum was answered with either "Strop it again" or "You Over Honed it"
It took a ton of work from quite a few people to push the onus of correct honing to the bevel and not the finisher...Once that was done and more people began to get the "Honing" down, the "Overhoning" talk began to disappear..
Once you learn to relax after the bevel set and ease into the finishing stages then taking an edge to far should never be a problem.. and even if you do it is easy to fix..
What the OP was describing is probably just too much edge for him and his face, as he learns to strop better and better he will adjust that edge to his face.. As he gets better and better with shaving and adjusting pressure and angle the edge will also magically feel better :) Also people tend to move toward the razors that feel better on their face.. Everytime a razor doesn't do quite right it isn't always the razors fault, but yes you can create a fagile edge by Mis-Honing the blade :p
(if you wanted to go really advanced we could discuss my thoughts about why some stones work better for some steels)
:popcorn:
Where's the fin?Quote:
Originally Posted by unit
Yeah, well, all models tend to be over simplified for demonstration purposes...if you want to get really technical about it, my apex angle is well outside the acceptable range for straight razors in those images.:gaah:Quote:
Originally Posted by gssixgun
and c'mon, look at my handwriting...you are lucky there is not coffee stains and lunch on this drawing!:D
Actually, this is something I might enjoy discussing at some point. I have developed similar hunches with regard to steels and hones for knives...it seems reasonable to think there could be good and bad marriages between steels and hones...but you have to be a few standard deviations away from the average hone job:dropjaw:Quote:
Originally Posted by gssixgun
There might be a better venue for such a discussion, but if you ever start one, send me a link;)
Great pic which brings to mind, Not to hijack this thread, I would think that if this edge was not polished that it would make the shave harsh or would this shave angle be to shallow. Lowest exp if the hone in the pic what the surface of your skin.
Glen I read your blog a little while ago. I'm new to hones but would like to hear your thoughts on the diffs between the w&b and Friodur's and why?
Alex
Verhoven http://www.google.com/url?sa=t&rct=j...dOblj9NWadTmUwQuote:
Originally Posted by DaveW
has SEM photos of .5 micron edges.
You will be disappointed. He didn't observe the effects of stropping. Glen did some stropping tests a while back indicating that overworking the edge at higher grits (as in pasted strops) wasn't a practical consideration.
I have intentionally worked edges with a barber hone til it was apparent at 45x the edge had broken down. It was "overworked". The edges went from straight and even and sturdy enough to cut without apparent damage to feathered and burred which would break while cutting and result in course torn steel.
IMHO those times we have a edge which seems harsh the culprit is very tiny "teeth" from the scratches which sub-microscopically run all the way to the edge and protrude. Our face can feel them but they are too small for even the SEM to view. Burnishing(or actually pressure flowing them) by stropping smoothes those tiny points back to the straight of the edge. At such a granularity which must be significantly sub .5 microns the steel actually is formed by pressure and heat from the leather. At this small scale steel isn't behaving like we observe it to at 45x. Your own skin burnishes the razor. Leather is tougher and doesn't complain.
Recently someone was testing a honing job I did. One comment was "harsh" so they stropped the blade. Further stropping beyond what I had done took the razor from sharp but harsh to simply smooth. Often users comment about Feather blades being too sharp or harsh until they are shaved a couple of times........burnished from use. Here is where YMMV or personal preference comes into play. Someone with finer sensory ability (denser nerve endings?) would feel the "teeth" more acutely.
Finally consider what has been published about DE blades. They are honed to 1K or less and then subjected to machine burnishing and coatings.
The situation of a razor losing sharpness part way through a shave might be nothing more than a underdeveloped honed edge which is cutting by virtue of some "teeth" which are extending past the edge which hasn't yet been properly developed by getting both planes to meet evenly. The shave-ability of such an edge quickly disappears as those teeth are burnished back to the edge which hasn't yet been properly formed .
All this indicates to me the knife sharp term of "wire edge" or burred edge(the often recommended treatment is drawing the blade through some material to tear off the burr) isn't a term which accurately describes what happens when we get above 4k-8k grit level.
I don't believe at .5 microns and below there is any steel which is going to survive much flexing back and forth against skin or leather. It would seem to me stropping works because at these sub-visual levels the steel is being formed into a smoother boundary which slides more easily across the nerve fibers on our face whereas the unstropped edge has the capacity to rake across these nerves and cause discomfort. Both of these conditions result in sharpness which for a knife would be superior but when applied to the sensitive skin on your throat are very different indeed.
Go for it. I've not seen a lot of information about the alloys used on the first razors that got away from plainer carbon steels. We know a lot about the diemaking steels now (A2, O1, D2, and W1..what's left of it) in terms of what their carbides are, and what cuts them the best.Quote:
Originally Posted by gssixgun
I haven't seen a lot about alloys from pre WWII, though, and how precisely they were hardened and tempered to avoid carbides (what they look like microscopically, etc). Regardless, anything with modern al-ox, ceramics alumina, silcon carbide, diamonds, chromium oxide - cuts them all, hard carbides or not.
Lee valley has just released a powder metal that sharpens about like A2, has about twice the wear resistance in wood, but seems to hold acute angles better even than carbon steel. It's not a high speed steel, and they won't divulge secrets, but if it holds acute angles and has no large particles, it would be fantastic for razors. It seems to do well in both chisels and plane irons, which pretty much covers damage due to impact (which hairs do) and adhesive wear (which strops do, and hairs probably do, too). If it has that kind of wear and impact resistance, but still can be sharpened on natural stones, it would straight up be better than anything out there right now that razor makers are carrying over from bearing steel, knife making steel or diemaking steels.
I enjoyed your post (even the parts I removed in the quote above).Quote:
Originally Posted by jaswarb
I have surmised that (at least with some of the high carbide particle metallurgy steels in the knife world) that there is a point where the steel stops behaving as a homogeneous entity and starts to really show its heterogeneity (based on the scale of abrasives used). I lack the ability to test this, but I thought I would share the hypothesis.
Some steels seem to really be happy with coarse finished edges, while others seem to keep getting better as the grits get higher (to a point perhaps)...at least this is what I have observed in practice/trials.
Quote:
Originally Posted by unit
I concur. I believe one significant reason the powdered steels are advancing the art is they are more homogeneous and Hitachi's White steel can be taken to an incredibly fine hard edge which doesn't normally appear to have grain.
I would surmise that "it depends" (and admittedly this drawing is pretty simplified)...but for the sake of simplicity, lets play...Quote:
Originally Posted by kalanyon
If the honing continued until the bevels were polished all the way to the edge (or apex), the result would be a very sharp edge that is VERY delicate because the effective edge bevel angle would be much lower...giving the result of minimal support behind the apex.
If the honing stopped as shown in the bottom drawing and only the green material was removed, the resulting edge would not be polished (at least not by the honing efforts depicted in the drawing), it would not be made any sharper by the efforts depicted, and it would be weakened, but not to the extent of the example in the paragraph above.
The result in reality would probably be more like a convex shaped bevel (as a result of honing pressures being varied all over the place by inconsistent honing technique) with an effective apex angle on par with the geometry of the razor (therefore sharp) but ample shoulder material removed causing weakening.
This whole discussion sort of illustrates the importance of magnification in conjunction with a thorough shave test....at least to this novice;)
I dunno, all I see are two bicycle seats and a Phillips screwdriver head.Quote:
Originally Posted by hoglahoo
White #1 and White #2 are excellent, even Blue #1 and #2 would be great.Quote:
Originally Posted by jaswarb
Pre 1900 razors, what were they made of? On the list of carbon steels, they were one notch above file steel as the best grade of steel. But did they have vanadium carbides? Or were they an attempt at the best crucible process steel?
Quote:
Originally Posted by DaveW
Bingo give that man a cigar... We barely know some of the hardness factors let alone what they really were alloy wise... So as you hone them you start figuring out what they work best with,, now keep in mind that this is only according to your face unless you happen to do this professionaly and can keep getting feedback from multiple customers... This can sometimes point you in the right direction...
Only a few of the Custom Makers have branched out into "Super Steels" some with less then stellar results, I have honed a few of them..
Some of the Japanese makers have used Tamahagane steel and I have coaxed very nice edges out of them...
The common belief is that Vintage razors were made mostly from simple tool steel, I know many of the custom guys that have tried the newer steels have wandered back to the O1 you might ask them why....
Presume on the O1 because you can harden and temper them very accurately without vacuum heat treatment or stainless steel wraps, etc. It's also easy to hone compared to higher alloy steels, and tends to drop off particles (and in the case of tools, wire edges) at a lower grit.
Every time I see the word tamahagane, I wonder what's actually in a razor. Is it really sand iron that is beaten to remove silica, and then provided carbon from charcoal? In the world of tools, it's well known that many tools that are marked tamahagane are some sort of mass produced carbon steel, and the term is used as a marketing term.
I've seen that iwasaki uses the term tamahagane, and it would be unlikely that he / his shop would abuse it. But I do think based on So Yamashita's comment on his page about actual tamahagane, that its value is collector and marketing and not function. Hitachi white paper steel and the older english and swedish plain steels are so good at taking a great edge at lower grits. I would think they would be a better choice for razors than O1, but they are more expensive, harder to heat treat, and lose temper at a lower temperature.
if the custom makers are using a "super steel", they'd have to sink a lot of money and experimentation into it to get a schedule down, it probably just isn't worth the trouble when O1 makes a very good and predictable razor with very cheap stock.
There are so many variables, that sometimes it's easier just to find something (razor) that works well with something else (stone) and not worry about it. I should be in that category. I have a lot of somethings that work fabulously with other somethings, empirical trumps theoretical because the former is known, I just wish I could resist trying to figure out why when it doesn't change the result.
Not being a versed in the art of forging steels I can only speculate from what the master of pounding iron pass along.Quote:
Originally Posted by gssixgun
They consistently mention the time and effort spent learning how to best handle a particular metal. It would seem to be a considerable investment as many of them work on only one or two alloys expecting to get the very most from the material.
Consider straight razors were made in the millions......tens or hundreds of millions. Whatever steel they chose to work the opportunity to refine the results was far richer than any individual or company can hope for today.
From a source forgotten I read one company in upstate NY was finishing as many as 9,000 razors a day. Over a hundred year period that is an enormous amount of development opportunity.
I'm working on having a couple razors, western ground, done in Hitachi White made for me.Quote:
Originally Posted by DaveW
The goal is to have one made in each of the two varieties.
Early days yet, but I look forward to seeing how this will turn out..
[QUOTE=Birnando;.......... I look forward to seeing how this will turn out..[/QUOTE]
I look forward to read your results. I have knives of Hitachi White #1 they are a revelation.
Incredible edges which are quite easy to sharpen and last a long time are the rule. For knives the edge
geometry is responsible for much of the performance. I suspect razors will better demonstrate
the properties of the steel itself.
Yep, I have a few knives in Hitachi White #1 and #2 as well, and that's the reason for me wanting to see how razors will do with it.Quote:
Originally Posted by jaswarb
Rest assured, I will post about them as soon as they are made!
I hope they turn out well, if they do they should be superior razors. I love white #1 and white #2.Quote:
Originally Posted by Birnando
You are correct, that was Genco.Quote:
Originally Posted by jaswarb
The Hardware review - Google Books
That is pretty cool, I didn't ever see that before about Genco,,, but for some reason I thought Torrey produced the most straight razors overall I could have sworn I read that someplace... Looking :)
I have read Torrey produced the most overall but never have found a source able to quote a total. Considering Genco wasn't the biggest manufacturer by any account and factoring the number of factories worldwide...............there are a lot of razors to be accounted for.Quote:
Originally Posted by gssixgun
Many went to scrap or trash long ago but given the numbers manufactured there must still be millions left.
Just think what the custom makers today might create given the opportunity to sell in these numbers.