Honing to a frown

[bluesman 7]

At the first Denver meet that I went to in early 2013. The most experienced person there was demonstrating an X stroke. The razor was a normal straight edged razor and I was confused as to why an x stroke was used as opposed to the straight strokes that I had been using. He stated that 'You should always hone towards a smile, if you don't you will develop a frown.' At the time this made no sense to me at all. I'm still not sure that I agree with the statement completely, but I have seen evidence to support it.

A bit later Brooksie (remember him?)started a thread where he honed a razor to a frown, breadknifed it, and honed it to a frown again! I could not see how that could happen with a flat stone, and I was sure that Brooksie would have checked his stone for flatness.

The recent thread Chronicles of a terrible honer ;) has brought this back into topic, and rather than confuse the OP of that thread with what will probably be a confusing, contested, and hopefully interesting and educational discussion, I thought that I would start a new thread.

EDIT; I have more to say, but will let this ferment a bit first

 

[eKretz]

That is definitely correct when the razor is longer than the hone width. The reason for this is the same reason that a sharpening stone naturally develops a "dish" or low in the middle shape. If you look at the contact between razor and hone, the middle of the blade is always rubbing on the hone, while the heel and toe alternately miss the hone for part of the stroke.

It can certainly happen with a hone that is wider also however - especially with a less experienced honer - as the rolling x-stroke can similarly make contact from the center to the heel, and alternatively from the center to the toe as the stroke progresses if the pressure isn't manipulated correctly, with the same result. If the pressure is done right, the center should be under zero pressure at the beginning and end of the stroke, and then the tendency for the frown to develop will be reduced or eliminated.

Edit: even with a perfectly straight edge, this can occur, as it's quite difficult - especially so for beginning honers - to maintain perfectly equal pressure along the length of even a straight edge without unintentionally biasing in one direction or the other.

 

[bluesman 7]

Hi Eric, glad you joined in. Good description regarding X strokes, but how about how it can easily happen with straight ,non X, strokes that are popular among the 'keep the edge dead straight' afficianadoes.

 

[eKretz]

I edited to add that. Must have been while you were composing your message. I think most folks would be quite surprised how much their actual applied pressure from heel to toe varies even when using what they think applies even pressure on a straight edge if they could actually measure it. While one is trying to apply even pressure along an edge that's sticking out extended past one's point of hold (commonly described as "cantilevered" in engineering parlance) while razor honing, it's extremely difficult to actually do in practice while the arm and wrist are in motion and changing position.

A good stroke for a perfectly straight edge that prevents this "frown effect" might be one similar to Alex Gilmore's in his Ax method videos but without sliding a finger along the blade - instead merely supporting it at both ends. However that could induce other issues. None are perfect, so we choose what suits us and work around the issues.

 

[buca3152]

I saw a guy hone a frown into an extra hollow razor on a dmt 600 in half a minute. Straight on strokes. The dmt is flat. One hand on the blade. I have to believe my own eyes.

 

[bluesman 7]

As a thought experiment, picture a full hollow grind shoulderless razor with a perfectly straight edge, a perfectly aligned spine, and a perfectly flat and uniform hone that is at least as wide as the edge.

With an even torque on the razor the pressure would appear to be even all along the edge, but since the toe and heel are less supported than the center there is more pressure per unit area on the center of the blade, creating a frown. The higher the overall torque or pressure, and the thinner the grind, the more the pressure difference between the ends and the center of the edge.

Placing thumbs or fingers on the toe and heel to even out this pressure creates the problem of balancing this pressure throughout the whole honing sequence.

I'm not trying to make the case that honing is difficult. Just making the case for how a frown can occur while everything appears to be starting out perfect. In the real world, imperfect grinds, imperfect spine alignment, etc. complicate these issues.

 

[buca3152]

Yes I agree. Too much pressure was used on the example I gave you. However I think a heel forward stroke is more apt to not create that issue. I hone that way anyway. I haven't studied that as I've never honed a frown into a blade.

 

[eKretz]

Yep. Definitely can and does happen. There are actually a lot of factors involved in something as "simple" as honing a razor.

 

[Seveneighth]

That is definitely correct when the razor is longer than the hone width. The reason for this is the same reason that a sharpening stone naturally develops a "dish" or low in the middle shape. If you look at the contact between razor and hone, the middle of the blade is always rubbing on the hone, while the heel and toe alternately miss the hone for part of the stroke.

It can certainly happen with a hone that is wider also however - especially with a less experienced honer - as the rolling x-stroke can similarly make contact from the center to the heel, and alternatively from the center to the toe as the stroke progresses if the pressure isn't manipulated correctly, with the same result. If the pressure is done right, the center should be under zero pressure at the beginning and end of the stroke, and then the tendency for the frown to develop will be reduced or eliminated.

Edit: even with a perfectly straight edge, this can occur, as it's quite difficult - especially so for beginning honers - to maintain perfectly equal pressure along the length of even a straight edge without unintentionally biasing in one direction or the other.

Do you not compensate for this if you are applying torque to the edge as you run your X stroke? I always try to vary the torque so that I get even amount pressure × contact on the hone for each part of the edge. Heal and toe especially seem to need proportionately more.

Genuinely asking because you have me worried...

 

[stone and strop]

I have not noticed this effect at all. I think if anything someone who has honed for a long time with gravitate toward a slight smile.
I would say that the good majority of frowning blades are purely from too much pressure either by torque or center downward force.
People being obsessed because of warnings to keep the blade flat put a finger in the middle of the spine when starting out.
Habits become bad habits sometimes.
As far as keeping a straight edge what I did for a few years was keep a finger on the spine with no pressure other than to direct and keep the blade in line with the other end. (two handed honing) Extra care has to be taken that the added finger is not there for pressure.
On a flat hone the edge will remain straight.
I remember a video from Sham years ago about teaching people to hone and keep the blade flat.
He recommended (with one hand) to place a finger near center with no pressure to build muscle memory of the feeling of the razor sitting flat on the hone and when this became second nature remove the finger and hone as normal.
To this day I have never felt the need to torque a razor.
The pressure said should be light and even. The razor should be checked periodically by sighting down the edge especially while learning. Its much easier to repair before it gets out of hand.
I think if you are getting frowns you are obviously doing something wrong and normal honing will not produce one.
I also think that the average experienced honer while doing an x will almost do a rolling x of the smallest degree to ensure he is getting the entire edge. Almost imperceptible.

 

[eKretz]

Do you not compensate for this if you are applying torque to the edge as you run your X stroke? I always try to vary the torque so that I get even amount pressure × contact on the hone for each part of the edge. Heal and toe especially seem to need proportionately more.

Genuinely asking because you have me worried...

No, you need to compensate with a sort of slight application of pressure in a rolling x fashion. Torque won't affect pressure in that direction.

 

[eKretz]

The only exception to that above would be if the blade is somehow stiffer in the center section as described by Vic, which isn't something I've found to be so on a huge amount of razors. This is different in every case of course depending on the grind straightness, but I've found that most razors of average grind are stiffest near the heel by the stabilizer, slightly less so in the middle and least of all near the toe.

And I would agree that this is almost always a beginner problem. The more advanced guys have got their stroke down and don't have this issue.

 

[combatcrab]

The recent thread Chronicles of a terrible honer ;) has brought this back into topic, and rather than confuse the OP of that thread with what will probably be a confusing, contested, and hopefully interesting and educational discussion, I thought that I would start a new thread.

EDIT; I have more to say, but will let this ferment a bit first

Hey cool, a shout-out! This is an interesting premise, I'm glad to have found it.

As I was scraping the razor tonight, I was really trying to wrap my head around how the frown could have occurred. This helps.



Sent from my Pixel 3 XL using Tapatalk

 

[Gamma]

I don't know that I totally agree with the concept of the blade being 'more supported' in the center than at the ends, or that the force of the edge at the stone would always be greater in the middle. Blade design could play into it though. I have no way to measure it, but I just did a simple test; using more torque than usual, the edge deflected perfectly evenely from toe to heel. To me, this shows equal force along the bevel at the stone. Or, at least, equal enough for that blade Of course, there are no perfect razors and hones or honers so the test should really be done by someone with a blade that is actually suffering from this.
Could it happen ? Sure, all kinds of stuff goes on. All kinds of stuff, all the time.
I've honed a good number of Kamisori that had perfectly straight edges, none turned into smiles or frowns. I did take in a Kamisori with a frown once though... never figured it out but the Omote had been assasinated. So, I figured some genius had attempted to use Iwasaki level pressure to hone the thing, or something along those lines.

Actual tangible things that I have seen cause frowns
.... non flat stones used by people not checking the stone in multiple places across both axes.
Ridiculous focused pressure on the spine.
Really bad spine geometry from bad manufacturing or bad honing or both.
People using skinny hones or a butchers steel.

 

[bluesman 7]

I have no way to measure it, but I just did a simple test; using more torque than usual, the edge deflected perfectly evenely from toe to heel. To me, this shows equal force along the bevel at the stone.

Surely you did not expect the toe and heel to lift up off of the stone to demonstrate lower pressure on those portions of the blade.

Picture a line of load cells under the edge. I can assure you that the load cells at the toe and heel would read lower pressure than the center cells.

Another demo; Cantilever a piece of plywood off of the edge of a table. Place a weight near the center as far as you can get from the table and measure the deflection. Now move the weight to one of the corners and measure the deflection.

EDIT; Actually, thinking about the above two scenarios I may have convinced myself that the pressure would be equal along the edge.

 

[David]

Lol

 

[dundak]

It's not really a scientific explanation but...At a gun show about 25 years back my dad and I were looking at some razors a gent had at a table. Most had frowns or smiles. I asked my dad "What causes that?". He replied "Some people hone their razors to damn much."

 

[buca3152]

So, it seems the conclusions were inconclusive.

 

[bluesman 7]

Conclusions in a honing forum what chu talkin bout.

 

[buca3152]

Aha! So maybe a lot of this stuff is just overthinking with no real value? Lol.