Honing with convex stones.

Bob Mck

Bob Mck

Messages
65
Gentlemen and ladies (if any happen to be checking this out) here in the United States there seems to be a great deal of uproar about honing with flat stones vs convex stones. Now, those raving about the concave edge are adamant about the higher quality and greater degree of sharpness the razor benefits from this type of sharpening. One Gentlemen, and I have no reason to doubt his word, quotes the President of Thiers Issard as sayin that Americans will never understand the quality difference of a concave edge vs a flat edge. Inferring that concave honing and sharpening is the normal procedure in Europe.
I ask you my overseas brethren, not to get involved in the discussion too deeply but only to answer how you sharpen/hone your razors. Either with convex or flat stones.
Thank you for your time.

Bob
 
I am far from an expert honer, in fact, I would call my honing skills somewhere between non-existent and marginally proficient, but I suspect I'm a big part of the reason for the current uproar. If you asked this a year ago, I would have said it's good for honing wonky razors and that's about it, but I've been persuaded to actually try it out and give it a reasonable chance.

Luckily I have a wet shaving machinist friend who was willing to make me some plates so I could explore this nonsense, so I do have a 1.7m, 5m, and 8m cylindrical plate, and a combo 2m/7m elliptical plate to fully delve into this stupid stuff.

The facts: it does thin the bevel, enough that stropping does not remove the concavity. Much of the thinning effect is towards the rear of the bevel, so it doesn't change the angle of the bevel as much as the nay-sayers say it does. It does make the edge more flexible. The edge does not last as long as a convex edge. The edge does get keener than I am capable of honing on flat stones, for what that's worth.

I hone on both convex and flat hones. Which I choose is largely razor dependent. You can't slap just any razor on a convex hone and get a good edge, with some razors the steel can't take that refined an edge, and some razors just won't hone on a convex stone, like a wedge grind.

I find it both easier and quicker to hone on convex stones, though one must be very careful to keep the razor at a 90° angle to the edge of the stone, any skewing of the blade will rapidly widen the bevel. Sloppy honing will screw up the razor.

It's just another honing technique, and like any other technique, it has it's fans and detractors. Unfortunately, asinine behavior from many of the fans tends to alienate them from the wider wet shaving audience. Many of the detractors have honed on slightly crowned stones and have dismissed the idea as rubbish, which I think does the technique a disservice, since the full effect is not felt until the razor has been honed on a small radius stone, and you won't get that from your typical dished glass or marble plate, which is what most of them use as the basis of their 'experience' with convex honing.

Is it the holy grail of straight razor honing? No. Do I personally prefer concave edges from convex hones? Yes. Can convexing a marginal stone help improve it's speed and cutting ability? Yes.

Someone on B&B posted that he thought all stones should be flat, with the exception of Arkansas stones, which all ought to be convexed. I largely agree with that sentiment, though I think it was mostly focused on the fact that maintaining softer stones is not as easy if you don't have the proper plates to do so.

I'll be happy to answer any other questions anyone has.
 
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Bob Mck said:
...Inferring that concave honing and sharpening is the normal procedure in Europe...
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It might be the practice at Thiers Issard and Dovo, but to the best of my knowledge, no other major razor makers do so. On the other hand, I'm not sure that there are any really old razor makers left other than those two, and seeing how all the reference works relating to convex honing date to the mid-1800's, it's not surprising that this knowledge would have been lost or forgotten by the other manufacturers.

The other reason for this loss of knowledge is attributed to the use of Arkansas wheels for honing, beginning in the late 1800's and early 1900's. Production of those wheels stopped in the mid-1900's, and razor manufacturers purchased nearly the entire world supply, hoarding and using them. They used up the last of those about 40 years ago, at which point they reverted back to use of convex hones for honing. I'm not 100% sure of those dates, but that's the general gist of the history of convex honing.

I believe it's possible that convex honing may have been widespread in Europe at some time in the past, but that is certainly no longer the case.

Edit: as an interesting side note, many vintage Pierre Du Sud Ouest stones are found to be convex. Unfortunately, there is no historical reference as to why they were shaped so, or for what sharpening purpose they were used, so we can't use that fact as a convex razor hone reference.

The one craft that does still use convex hones, or at the very least, wheels, is the barber's sharpener. Barbers send their shears to specialists to be re-sharpened, not to the average Joe who runs a knife sharpening business, unless that person happens to be trained on the proper method of regrinding shears.

Sorry for completely derailing your thread, Bob, and for going far beyond the bounds of what you asked.

At the end of the day, the only person who really cares about the edge on your razor is the guy watching you from your mirror. Anyone else with a negative opinion on how YOU hone YOUR razor needs to check their ego at the door. After all, 20 years ago these same experts were using the pyramid honing method. 20 years from now, there will probably be other honing regimens that will take center stage. I don't foresee convex honing being that method, unless 3D printing makes shaped plates easily and cheaply accessible to the average person.
Bob Mck said:
...One Gentlemen, and I have no reason to doubt his word, quotes the President of Thiers Issard as sayin that Americans will never understand the quality difference of a concave edge vs a flat edge...
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You know Jarrod @thesuperiorshave is a member here, right? He just doesn't post here very often.
 
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PLANofMAN said:
It might be the practice at Thiers Issard and Dovo, but to the best of my knowledge, no other major razor makers do so. On the other hand, I'm not sure that there are any really old razor makers left other than those two, and seeing how all the reference works relating to convex honing date to the mid-1800's, it's not surprising that this knowledge would have been lost or forgotten by the other manufacturers.

The other reason for this loss of knowledge is attributed to the use of Arkansas wheels for honing, beginning in the late 1800's and early 1900's. Production of those wheels stopped in the mid-1900's, and razor manufacturers purchased nearly the entire world supply, hoarding and using them. They used up the last of those about 40 years ago, at which point they reverted back to use of convex hones for honing. I'm not 100% sure of those dates, but that's the general gist of the history of convex honing.

I believe it's possible that convex honing may have been widespread in Europe at some time in the past, but that is certainly no longer the case.

Edit: as an interesting side note, many vintage Pierre Du Sud Ouest stones are found to be convex. Unfortunately, there is no historical reference as to why they were shaped so, or for what sharpening purpose they were used, so we can't use that fact as a convex razor hone reference.

The one craft that does still use convex hones, or at the very least, wheels, is the barber's sharpener. Barbers send their shears to specialists to be re-sharpened, not to the average Joe who runs a knife sharpening business, unless that person happens to be trained on the proper method of regrinding shears.

Sorry for completely derailing your thread, Bob, and for going far beyond the bounds of what you asked.

At the end of the day, the only person who really cares about the edge on your razor is the guy watching you from your mirror. Anyone else with a negative opinion on how YOU hone YOUR razor needs to check their ego at the door. After all, 20 years ago these same experts were using the pyramid honing method. 20 years from now, there will probably be other honing regimens that will take center stage. I don't foresee convex honing being that method, unless 3D printing makes shaped plates easily and cheaply accessible to the average person.

You know Jarrod @thesuperiorshave is a member here, right? He just doesn't post here very often.
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Wow! Super answer!
Thank you so much for the clarification and the information! I've learned quite a lot from your posts.
Actually, I didn't know Jarrod was on this forum. I had actually been planning on emailing him about this subject since he is super stoked about it. However, after watching several of his videos I didn't know how offensive my questions would be to him or if he would even answer me (I live in Tennessee and one of the last of his videos I watched he opened and closed the video with the statement "Tennessee you are dead to me") I have been intrigued by the whole concave honing, but unsure of changing the face of my stones for it nor sending one of my razors off for someone else to concave hone it without a way to even strop it when I get it back.

Anyway, many thanks for the answers!
 
Bob Mck said:
Wow! Super answer!
Thank you so much for the clarification and the information! I've learned quite a lot from your posts.
Actually, I didn't know Jarrod was on this forum. I had actually been planning on emailing him about this subject since he is super stoked about it. However, after watching several of his videos I didn't know how offensive my questions would be to him or if he would even answer me (I live in Tennessee and one of the last of his videos I watched he opened and closed the video with the statement "Tennessee you are dead to me") I have been intrigued by the whole concave honing, but unsure of changing the face of my stones for it nor sending one of my razors off for someone else to concave hone it without a way to even strop it when I get it back.

Anyway, many thanks for the answers!
Click to expand...
Your questions won't be offensive to him, and he will answer. He even talks to me. Granted, because of my initial (very public) negative views on convex honing, he was incredibly condescending to me initially. You'll probably get to avoid that particular aspect of his personality. He is a treasure trove of knowledge regarding the historical aspects of convex honing, and an extremely skilled honer, on flat stones or convex.

Bill M. (On YouTube and at The Shaving Cadre forum) is a good resource, as is John (JPO) on various forums. Of the three of them, John is the most knowledgeable about the science and theoretical application of concave edges.

Bill M. is probably a good person to talk to, but due to his negative association with The Shave Den and my current status there as a moderator, he was unwilling to discuss convex honing with me.

I would recommend you try a convex edge before you do anything drastic to your stones. I would also recommend that you be very selective on your razor choice that you send out for honing. It should be a hard, fine grained steel, something that is capable of holding a refined edge.
 
PLANofMAN said:
Your questions won't be offensive to him, and he will answer. He even talks to me. Granted, because of my initial (very public) negative views on convex honing, he was incredibly condescending to me initially. You'll probably get to avoid that particular aspect of his personality. He is a treasure trove of knowledge regarding the historical aspects of convex honing, and an extremely skilled honer, on flat stones or convex.

Bill M. (On YouTube and at The Shaving Cadre forum) is a good resource, as is John (JPO) on various forums. Of the three of them, John is the most knowledgeable about the science and theoretical application of concave edges.

Bill M. is probably a good person to talk to, but due to his negative association with The Shave Den and my current status there as a moderator, he was unwilling to discuss convex honing with me.

I would recommend you try a convex edge before you do anything drastic to your stones. I would also recommend that you be very selective on your razor choice that you send out for honing. It should be a hard, fine grained steel, something that is capable of holding a refined edge.
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It seems I'll try to get in touch with either Jarrod or Bill, I'm familiar with Bill from the Cadre so I'll connect with him first.
Thank-you once again sir.
 
The Jacksonville Jaguars were playing the Tennessee Titans in the 2022 NFL Week 18 season finale on the day of the referenced video, hence the "TN u r dead 2 me" *joke* (= a historical relic describing a concept where people would endeavor to make others laugh via a tool known at the time as "comedy", generally by employing one of the "three i" comedy concepts [irrelevance, immaturity, or irony, this being the "irony" genre as it would not generally have been considered rationale for one party to dismiss the entire population of another state over the stakes of a football contest, thus highlighting the absurd decree's originator's faux-dedication to their regional sporting contest representatives]).

They're just bits, guys. If they make u feel confused about if they were supposed to be funny or not, then they hit the mark - the "Schrödeninger's Cat of Comedy", as I refer to that nexus, is in fact the funniest part of all, for it shouldn't exist...nothing should be half alive, or half funny.

We'll all likely be dead in another 100yrs.


Happy shaving, however u do it!
 
My apologies sir!
I only viewed that video once and I should have paid more attention to the opening. As however I am a Philadelphia Eagles fan I can actually relate, except it would be Texas for me (lol).
However, since I have you on the thread here and don't (I hope) harbor any disdain for me. Could you answer a question for me?
It being that with a concave hone, is the flexibility of the blade the major advantage to this style of sharpening or is it the added sharpness?
And if it is the sharpness how much, if any, does the geometry of the blade angle change?
I'm sure you have covered this in a prior post somewhere and if you can point me in that direction I would be grateful.
 
btw, can't speak to how it works in France, but in Germany, one cannot legally offer most products made by hand [soap, brushes, cuckoo clocks, razors, etc.] or perform services done with hand [barber, nail tech, baker, tattoo artist, etc.] to the general public without having a "master" on the premises, and their certification of mastery on display. Each various trade has their own codified rules of mastery, but any freestanding business entity has to have 1+ masters. For grinding specifically, a 'master grinder' has to go to a grinding school in NWR for 3yrs after 2yrs full time as an apprentice under an incumbent master, so master grinders have 5 full yrs dedicated work+study. At this grinding school, they have always taught of convex hones, and in fact shaping by hand a hone as a proof of apprenticeship has been a grinder's test well over a century.

Any Solingen marque, be it Aust Dovo Revisor Böker Erbe Wacker whomever, if they're offering new make to the public, grinders there know about convex hones, and of course the long deceased wheels made of Thuringian slate or Arkansas stone...because they would either have to be a master themselves or be under a master's direction/supervision, where concave bevel discussions would not be taboo and would in fact be compulsory. The old 1846 grinder book first mentioning it directly was a textbook for students at such a school, which back then would've been many magnitudes larger (and not confined to one remaining classroom in Düsseldorf).

Even today, in the most recent Böker "Barber's Corner" publication, there is a direct and obvious reference to the bevel intentionally being concave; they tout the ultimate razor being the bellied extra hollow (which is all they still offer), and state that the belly "lies in front of the hollow grind zone and just behind the edge, *which has a small hollow grind itself*". The 'edge' in the way grinders speak of it in English, is what we native speakers commonly call the 'bevel', and what we natives commonly call the "edge", in English the grinders generally denote that as the "apex".
 
yes, the flex is the big thing, the lesser but still empirical advantages are that the blade thickness (at a nominal _microns behind the apex) is reduced, and there is a small reduction in apex °, generally -0.2° or less.

But the difference of the flexibility is easy for anyone to discern if they have familiarity to a blade from use with a flat bevel, and then essentially only altered that facet of its edge metrics. Unlike measuring thickness 200 microns rearward, or measuring inclusive angle, putting flex of a bevel in to objective/measurable terms isn't simple. But the razor's edge will be quicker to flex and do so with less pressure.

I have no interest in knowingly shaving with blades that don't benefit from a concave bevel (which, yes, certainly exist - I just think that indicates they lie below the forging/grinding pinnacle).

I have not found any meaningul edge retention depreciation in the use of such blades that meet my standard, comparing my many yrs of their same use pre-convex-hone. An expertly forged and ground razor lies at the "highest common denominator ground" of the gravity model that is combining hardness/thinness/flexibility (as u increase any of those 3 traits it must by definition come at some concession of the other 2), if you are good at stropping and lathering and angles with a str8rzr, near as I can tell over many hundreds of sessions the last 3-4yrs over many razors, concave honing's only drawbacks are tool prep (!) and the difficulty of avoiding cosmetic superfine abrasions either in the hollow grind area or between the belly and the rear of the bevel (in fact I now view those as proof of geometrically 'proper' honing, and I LOVE that TIs could show those marks on any model and at any price point).

If only any of us writing had had a shave straight off a 20cm-diameter Pike Hard Arkansas wheel... I doubt any of us had, but that is so small and so fine, that back in the day an expert grinder would sharpen the razor entirely on such a stone, foot-powered in a water trough, via 3 phases of the spine always being off the wheel! In the last step, the spine-to-edge line would face tangential to the stone's periphery, the razor's ~1mm-long bevel only interacting with the abrasive for its final <0.3mm of span, can u imagine the skill required to tip a razor like that all freehand with such a step actually enhancing what was already done?!? Our razors, and our edges, I think are a far cry from what was available once, when a professional at 1890-1920 near a factory could have the very best grinds and forging combined with a tool better than anything I came up with or has existed in the past ~40yrs. My goal has always been not to have master grinding go away, but it will, sadly, and I suspect in my lifetime (which likely isn't 50 more yrs).
 
thesuperiorshave said:
yes, the flex is the big thing, the lesser but still empirical advantages are that the blade thickness (at a nominal _microns behind the apex) is reduced, and there is a small reduction in apex °, generally -0.2° or less.

But the difference of the flexibility is easy for anyone to discern if they have familiarity to a blade from use with a flat bevel, and then essentially only altered that facet of its edge metrics. Unlike measuring thickness 200 microns rearward, or measuring inclusive angle, putting flex of a bevel in to objective/measurable terms isn't simple. But the razor's edge will be quicker to flex and do so with less pressure.

I have no interest in knowingly shaving with blades that don't benefit from a concave bevel (which, yes, certainly exist - I just think that indicates they lie below the forging/grinding pinnacle).

I have not found any meaningul edge retention depreciation in the use of such blades that meet my standard, comparing my many yrs of their same use pre-convex-hone. An expertly forged and ground razor lies at the "highest common denominator ground" of the gravity model that is combining hardness/thinness/flexibility (as u increase any of those 3 traits it must by definition come at some concession of the other 2), if you are good at stropping and lathering and angles with a str8rzr, near as I can tell over many hundreds of sessions the last 3-4yrs over many razors, concave honing's only drawbacks are tool prep (!) and the difficulty of avoiding cosmetic superfine abrasions either in the hollow grind area or between the belly and the rear of the bevel (in fact I now view those as proof of geometrically 'proper' honing, and I LOVE that TIs could show those marks on any model and at any price point).

If only any of us writing had had a shave straight off a 20cm-diameter Pike Hard Arkansas wheel... I doubt any of us had, but that is so small and so fine, that back in the day an expert grinder would sharpen the razor entirely on such a stone, foot-powered in a water trough, via 3 phases of the spine always being off the wheel! In the last step, the spine-to-edge line would face tangential to the stone's periphery, the razor's ~1mm-long bevel only interacting with the abrasive for its final <0.3mm of span, can u imagine the skill required to tip a razor like that all freehand with such a step actually enhancing what was already done?!? Our razors, and our edges, I think are a far cry from what was available once, when a professional at 1890-1920 near a factory could have the very best grinds and forging combined with a tool better than anything I came up with or has existed in the past ~40yrs. My goal has always been not to have master grinding go away, but it will, sadly, and I suspect in my lifetime (which likely isn't 50 more yrs).
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Thank you sir for answering the questions I had. I have been watching your videos for a little while and I do subscribe to your channel (BTW, glad your ordeal with customs is over). I shall now return to digging through your forum posts and videos for more information about this process.
 
thesuperiorshave said:
yes, the flex is the big thing, the lesser but still empirical advantages are that the blade thickness (at a nominal _microns behind the apex) is reduced, and there is a small reduction in apex °, generally -0.2° or less.

But the difference of the flexibility is easy for anyone to discern if they have familiarity to a blade from use with a flat bevel, and then essentially only altered that facet of its edge metrics. Unlike measuring thickness 200 microns rearward, or measuring inclusive angle, putting flex of a bevel in to objective/measurable terms isn't simple. But the razor's edge will be quicker to flex and do so with less pressure.
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That's what I've seen as well, with the additional caveat if one was wanting to experience bevel flex without apex thinning, a person could just do a bevel set on a small radius hone, and do all further steps on flat hones.

Alternatively, you could do a full progression of convex hones, and eventually achieve the exact same thing through repeated stroppings.

The edge would eventually go from Feather feeling sharp down to Derby feeling sharp, and if you like both blades, that's an okay thing, I guess. The edge below is closer to the 'feather feeling sharp' than the 'Derby feeling sharp' spectrum.
20230424_132215.jpg
This is what my bevel looks like after 5 shaves. I'd like to say all coticule edges look like crap, but I'm far from a good/talented honer. Despite appearances, it's reached that butter-edge consistency that is a hallmark of coticule edges.
The pic below is from the edge above.
IMG20230424105037.jpg

20230413_143838 (1).jpg
This is what it looked like right after honing and stropping. You can clearly see how the bevel has been shaped by the various diameters of different stones.



Bob Mck said:
And just what's wrong with bug protein? LOL!
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I'll eat a chocolate covered grasshopper, but I don't want my burger to be made out of the things. It's a fine distinction. I like to make my own food choices. Kind of like how most everyone on this forum is in here because they rejected their their local supermarket's shave offerings on some level.
 
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