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Convex balsa strop?

Just curious if it's of any consequence.

I know there are some widely varying opinions on the matter of convex hones, I am only interested in the logistics of how this may or may not work.

So as I understand, when a bevel is set on a convex hone the bevel results as concave, even if only by a fraction of a measurable amount. Therefore it would be most beneficial to continue progression on convex surfaces. However, if I were to apply this concept further to what is referred to as "the method" would it not be beneficial to convex the balsa wood medium for the diamond paste progression?

I get that the balsa is soft, so maybe basswood would be better? I am just curious if my line of reasoning has any merit and would like to hear any thoughts as to it's plausibility and/or tips on execution.
 

rbscebu

Girls call me Makaluod
I've never tried it, but then again, I'm not a convex type of bloke.

My thinking is that if everything is done using a convex honing medium, then yes, it would be best to use similarly convex balsa strops. If the convexity of the balsa strops matches that of the honing medium, then I can see no need to use something like basewood.

Balsa is considered a better medium than basewood for diamond pasting. It is a softer wood (not a softwood) that allows the diamond particles to properly embed themselves into the wood. With basewood, the diamond particles tend to stay more on the surface thus contributing to a "rougher" edge.
 
If I use a convex progression I strop on narrow hanging strops afterwards, one of which has paste on each side. This works for me.

You could use my convex method to convex your balsa.

I use a veritas lapping plate with wet n dry on top.
I flatten my stone.
Then I repeatedly do the following:
  1. I mark a cross-hatch pattern on the stone.
  2. I lap the stone away from me in a back and forth motion and rock up the trailing side very very slightly
  3. I do this on all four sides until a very thin strip of hatching is removed.
  4. I redraw the hatching and repeat for a slightly greater strip.
  5. After each lapping round I check with a straight edge to make sure that I am getting a linear convex by eye.
Once I have formed a cushion shape on the stone I will work in from each corner in an eliptical movement.

I didn't like the convex hone I got from TSS. The convexity was too shallow for my liking so instead I convex my own stones by hand with the method above. My feeling is that the convex shape does not need to be as perfect or as uniform as everyone says. I convex the stone so I know it's shape and I use it accordingly. I would never attempt an ark like this though, but it works well on synthetics and coticules.

In theory balsa should work the same, although I haven't tried it.
 

Slash McCoy

I freehand dog rockets
Just curious if it's of any consequence.

I know there are some widely varying opinions on the matter of convex hones, I am only interested in the logistics of how this may or may not work.

So as I understand, when a bevel is set on a convex hone the bevel results as concave, even if only by a fraction of a measurable amount. Therefore it would be most beneficial to continue progression on convex surfaces. However, if I were to apply this concept further to what is referred to as "the method" would it not be beneficial to convex the balsa wood medium for the diamond paste progression?

I get that the balsa is soft, so maybe basswood would be better? I am just curious if my line of reasoning has any merit and would like to hear any thoughts as to it's plausibility and/or tips on execution.

IMHO, no. Don't go there.

However if you want to try it, nobody is gonna stop you.

Have you already tried The Method? Following it precisely? That should be your benchmark reference if you want to try something like what you are suggesting. Same razor. I think when you compare results you will find that there is no point in using a set of convex balsa strops.

In fact I will postulate that when coming off a progression of convex stones, the edge will benefit more from flat balsa than convex. Essentially it would be creating a microbevel, but one that is easily sustained with the .1u balsa.
 
I've never tried it, but then again, I'm not a convex type of bloke.

My thinking is that if everything is done using a convex honing medium, then yes, it would be best to use similarly convex balsa strops. If the convexity of the balsa strops matches that of the honing medium, then I can see no need to use something like basewood.

Balsa is considered a better medium than basewood for diamond pasting. It is a softer wood (not a softwood) that allows the diamond particles to properly embed themselves into the wood. With basewood, the diamond particles tend to stay more on the surface thus contributing to a "rougher" edge.

Thank you. I hadn't really considered the "softness" of the wood to be beneficial in this manner specifically.
 
Yep, that's why balsa, hanging strops, or leather is used for abrasive stropping, rather than just putting it on a metal/glass/granite plate. The compressive nature of the surface keeps the abrasives in contact and focuses most of the pressure right at the edge, rounding it off... making the action much much much more rapid/effective than honing on the same grit stone would be.

It's essentially similar to the "unicot" method from way back in the day, where you basically beveled and did a minute amount of sharpening on heavy coticule and/or BBW slurry , then added a layer of tape and finished on water on the coticule by adding a tiny secondary bevel. Abrasive stropping is functionally similar.


A convex balsa surface would just slightly increase this effect... probably not really accomplishing much if anything.
3 passes on a balsa strop with 0.5 micron paste can be enough off a 3micron stone... new users are often warned not to exceed 10-12 as it's overkill... doing the same on a 30k (~.62micron iirc) hone wouldn't do much.
 
Quite a few convex strop contraptions in the 19th century advertised or explained in patent application to imitate the better thinner edge you get from visiting the local cutler, a cutler that would probably at the time use a small abrasive wheel to hone the razor.

Therefore I would highly doubt a modern trend toward convex hone takes much risk to an edge if there was a time when these same razors were finished only on wheels in the factory (just smaller and smaller as they finished), because you can always make it a straight triangle again pretty easily and these shapes aren't anywhere near as intense as they were.

If you wrapped an old strop around something circular and put something spongy between the back of the strop and the wheel to give it a bit of flex, could this help abrasive focus at tip while still bending bevel inward for comfort?

Seveneighth do you have an approximate diameter you have reduced your stones to at maximum curve intensity, and were you able to do this with hard Arkansas? I would certainly be willing to mess with a Naniwa this way soft as it is to see if it makes any difference on the same razor using the Naniwa normally flattened.
 
IMHO, no. Don't go there.

However if you want to try it, nobody is gonna stop you.

Have you already tried The Method? Following it precisely? That should be your benchmark reference if you want to try something like what you are suggesting. Same razor. I think when you compare results you will find that there is no point in using a set of convex balsa strops.

In fact I will postulate that when coming off a progression of convex stones, the edge will benefit more from flat balsa than convex. Essentially it would be creating a microbevel, but one that is easily sustained with the .1u balsa.

I am still not completely sold on the concept of honing on convex stones and surfaces alike. The science of it interests me greatly, although as we know sometimes what seems evident in a scientific calculation ends up just not delivering in practical application. Nonetheless, once my curiosity is peeked I generally take it as far as I can until I've been satisfied that I at the very least understand the concept thoroughly, which currently I do not.

I do have flat balsa and if I find that there may be even a small increase in efficacy I will as you suggest be using the flat as a baseline for comparison. Very grateful for the replies.
 

Slash McCoy

I freehand dog rockets
If I use a convex progression I strop on narrow hanging strops afterwards, one of which has paste on each side. This works for me.

You could use my convex method to convex your balsa.

I use a veritas lapping plate with wet n dry on top.
I flatten my stone.
Then I repeatedly do the following:
  1. I mark a cross-hatch pattern on the stone.
  2. I lap the stone away from me in a back and forth motion and rock up the trailing side very very slightly
  3. I do this on all four sides until a very thin strip of hatching is removed.
  4. I redraw the hatching and repeat for a slightly greater strip.
  5. After each lapping round I check with a straight edge to make sure that I am getting a linear convex by eye.
Once I have formed a cushion shape on the stone I will work in from each corner in an eliptical movement.

I didn't like the convex hone I got from TSS. The convexity was too shallow for my liking so instead I convex my own stones by hand with the method above. My feeling is that the convex shape does not need to be as perfect or as uniform as everyone says. I convex the stone so I know it's shape and I use it accordingly. I would never attempt an ark like this though, but it works well on synthetics and coticules.

In theory balsa should work the same, although I haven't tried it.

I think you are right about the side to side. Not too critical. End to end might be a bit more critical, though. At the very least, the curvature should be fairly consistent from end to end for best results, I think.

I actually considered constructing a 24" or so balsa wheel. Well, 3 or 4 of them. .1u for sure, maybe also .5u, 2.5u, 10u diamond. I think with mechanical assistance, a 5x jump ought to be feasible. In wheel form, dressing the surface would be dead simple, with a tool rest and a sanding block. I have a 12kw and a couple of 5kw brushless DC (PMAC, to be more correct) motors and a couple of controllers just laying around so I could turn them as slow as 50RPM in direct drive. I got a couple of enclosed reduction gearboxes, too, a 2:1 and a 3:1, or I could cobble together a belt drive up to about 6:1 pretty easy. Thing is, I got to many other projects going on right now to spend so much time on something that might or might not work as good as what I am already doing.
 
I think you are right about the side to side. Not too critical. End to end might be a bit more critical, though. At the very least, the curvature should be fairly consistent from end to end for best results, I think.

I actually considered constructing a 24" or so balsa wheel. Well, 3 or 4 of them. .1u for sure, maybe also .5u, 2.5u, 10u diamond. I think with mechanical assistance, a 5x jump ought to be feasible. In wheel form, dressing the surface would be dead simple, with a tool rest and a sanding block. I have a 12kw and a couple of 5kw brushless DC (PMAC, to be more correct) motors and a couple of controllers just laying around so I could turn them as slow as 50RPM in direct drive. I got a couple of enclosed reduction gearboxes, too, a 2:1 and a 3:1, or I could cobble together a belt drive up to about 6:1 pretty easy. Thing is, I got to many other projects going on right now to spend so much time on something that might or might not work as good as what I am already doing.
Don't you know the rules? If you mention it you have to build it. 😂😂😂

Looking forward to pictures when you one-day make it. I like the idea of the 50rpm

How about a double wheel? - like the old Sheffield grindstone?
 

Slash McCoy

I freehand dog rockets
Can't do a double with direct drive. These motors are single ended. Belt driving an arbor would be okay.

I will build it. I have put it on my list.

It is a long list.
 
The reason I had proposed this question was because I recently received a new Dovo from tss which as most of you know is honed post factory to perfection on a convex hone. I know little to nothing about this method, but I am trying to understand more so I want to do so through experience.
Now as I understand one can finish a flat progressed edge on a convex hone if desired without much of a negative effect, however once progressed on convex hones taking an edge then to a flat finisher to touch up would yield less than desirable effects. Stop me if I'm wrong here. So with that in mind, being that I have a set of balsa wood diamond strops for touch ups, I was inquiring if anyone else thought it would be best to apply the same concept to the balsa.

So..jump ahead...I just used the flat balsa.
(Disclaimer, I am a novice at best so please treat me as such. Don't hold back)

I shaved 5 or 6 times with the new Dovo, both wtg and atg. The first few shaves were effortless, even for me when I got not one single weeper I call that a damn good shave. At 5th and 6th it was beginning to pull a tad. I strop before and after every shave on linen and horsehide, still a bit slow but only because I am careful. I took a loupe to it and everything looked fine so I just figured it was time to touch it up a tad on the balsa. No sense in asking if something there went awry, I am meticulous and follow Slash's method to the T.

When I got done I cleaned and stropped and took out the loupe again.

What I observed was that at the very edge I had almost created another tiny edge, as far as I could tell. Now I could be wrong, but I'm pretty sure no tape was used in the previous honing. Therefore I did not tape it and saw absolutely no reason to do so. I never do a dilucot progression, but I don't think this is the same. It passed HHT without a peep though.

*Well...I shaved.*

WTG - OMG it was like wiping whiskers off my face, a pleasant zipping sound singing from the blade.
ATG - Ouch. It seriously felt like I was using a vegetable peeler to trim a wire brush. I tried various angles and grips. I tried hydrating my lather more. Nothing helped. I kept on. RESULT: Weepers a-plenty!

I just don't get it! For the sake of honest reasoning I will say that I can get a little raw and my technique needs improving. But I rarely get weepers and right now my face is a speckled mess! There has to be something obvious going on here, but I need help understanding it. Even if it has nothing to do with the fact that I used a flat finishing method(technically, but balsa has give to it) on a convex progressed edge.

Thoughts? Criticisms? Musings? ....Lashings?
 
Just re-read the comment about the microbevel. As I do not have a great understanding of such can someone maybe elaborate on the benefits/drawbacks.
 

Slash McCoy

I freehand dog rockets
The reason I had proposed this question was because I recently received a new Dovo from tss which as most of you know is honed post factory to perfection on a convex hone. I know little to nothing about this method, but I am trying to understand more so I want to do so through experience.
Now as I understand one can finish a flat progressed edge on a convex hone if desired without much of a negative effect, however once progressed on convex hones taking an edge then to a flat finisher to touch up would yield less than desirable effects. Stop me if I'm wrong here. So with that in mind, being that I have a set of balsa wood diamond strops for touch ups, I was inquiring if anyone else thought it would be best to apply the same concept to the balsa.

So..jump ahead...I just used the flat balsa.
(Disclaimer, I am a novice at best so please treat me as such. Don't hold back)

I shaved 5 or 6 times with the new Dovo, both wtg and atg. The first few shaves were effortless, even for me when I got not one single weeper I call that a damn good shave. At 5th and 6th it was beginning to pull a tad. I strop before and after every shave on linen and horsehide, still a bit slow but only because I am careful. I took a loupe to it and everything looked fine so I just figured it was time to touch it up a tad on the balsa. No sense in asking if something there went awry, I am meticulous and follow Slash's method to the T.

When I got done I cleaned and stropped and took out the loupe again.

What I observed was that at the very edge I had almost created another tiny edge, as far as I could tell. Now I could be wrong, but I'm pretty sure no tape was used in the previous honing. Therefore I did not tape it and saw absolutely no reason to do so. I never do a dilucot progression, but I don't think this is the same. It passed HHT without a peep though.

*Well...I shaved.*

WTG - OMG it was like wiping whiskers off my face, a pleasant zipping sound singing from the blade.
ATG - Ouch. It seriously felt like I was using a vegetable peeler to trim a wire brush. I tried various angles and grips. I tried hydrating my lather more. Nothing helped. I kept on. RESULT: Weepers a-plenty!

I just don't get it! For the sake of honest reasoning I will say that I can get a little raw and my technique needs improving. But I rarely get weepers and right now my face is a speckled mess! There has to be something obvious going on here, but I need help understanding it. Even if it has nothing to do with the fact that I used a flat finishing method(technically, but balsa has give to it) on a convex progressed edge.

Thoughts? Criticisms? Musings? ....Lashings?

On the ATG, drop your shave angle to bare minimum. Let the spine nearly drag on the skin. Also try TWO WTG passes before ATG. And stretch the skin "upstream" always. Of course you could also drop ATG altogether. Two WTG passes with a very sharp edge makes for a rather nice shave.
 
You read my mind Slash. I'm usually a once wtg and once atg shaver, I do get varying results to be fair. And the angle definitely. I forget who posted it about if you have rough whiskers the edge could actually slide downward into the skin if your angle is too steep. I'll keep it shallow as you suggested.

You totally called it with the microbevel, inadvertently it is absolutely what occured. Since I have never intentionally done this to any edge I am just curious of others experiences.
 
The reason I had proposed this question was because I recently received a new Dovo from tss which as most of you know is honed post factory to perfection on a convex hone. I know little to nothing about this method, but I am trying to understand more so I want to do so through experience.
Now as I understand one can finish a flat progressed edge on a convex hone if desired without much of a negative effect, however once progressed on convex hones taking an edge then to a flat finisher to touch up would yield less than desirable effects. Stop me if I'm wrong here. So with that in mind, being that I have a set of balsa wood diamond strops for touch ups, I was inquiring if anyone else thought it would be best to apply the same concept to the balsa.

So..jump ahead...I just used the flat balsa.
(Disclaimer, I am a novice at best so please treat me as such. Don't hold back)

I shaved 5 or 6 times with the new Dovo, both wtg and atg. The first few shaves were effortless, even for me when I got not one single weeper I call that a damn good shave. At 5th and 6th it was beginning to pull a tad. I strop before and after every shave on linen and horsehide, still a bit slow but only because I am careful. I took a loupe to it and everything looked fine so I just figured it was time to touch it up a tad on the balsa. No sense in asking if something there went awry, I am meticulous and follow Slash's method to the T.

When I got done I cleaned and stropped and took out the loupe again.

What I observed was that at the very edge I had almost created another tiny edge, as far as I could tell. Now I could be wrong, but I'm pretty sure no tape was used in the previous honing. Therefore I did not tape it and saw absolutely no reason to do so. I never do a dilucot progression, but I don't think this is the same. It passed HHT without a peep though.

*Well...I shaved.*

WTG - OMG it was like wiping whiskers off my face, a pleasant zipping sound singing from the blade.
ATG - Ouch. It seriously felt like I was using a vegetable peeler to trim a wire brush. I tried various angles and grips. I tried hydrating my lather more. Nothing helped. I kept on. RESULT: Weepers a-plenty!

I just don't get it! For the sake of honest reasoning I will say that I can get a little raw and my technique needs improving. But I rarely get weepers and right now my face is a speckled mess! There has to be something obvious going on here, but I need help understanding it. Even if it has nothing to do with the fact that I used a flat finishing method(technically, but balsa has give to it) on a convex progressed edge.

Thoughts? Criticisms? Musings? ....Lashings?
Could be you created a wire edge on the touch up(it does sound like one the way you describe the shave), don't forget the pull strokes on the balsa to prevent that.
 
First a disclaimer. I have purchased a convex hone from TSS. His convex hones are much more subtle than mine. I didn't like the convexity and made my own. Not a criticism of Jarrod's hones - they are superlative - I just like something a little more convex. Why am I mentioning this? Well, my experience with convex hones will produce a more dramatic effect so you can dial back the results from anything that comes from TSS.

Now as I understand one can finish a flat progressed edge on a convex hone if desired without much of a negative effect, however once progressed on convex hones taking an edge then to a flat finisher to touch up would yield less than desirable effects.

I keep my convex progressions separate from my flat stones, however, on the convex threads others have happily switched back and forth. There is video somewhere showing honing after tape without tape and saying at the 1u to 0.5u mark you still even out the bevel so it doesn't matter.

These two data points should reassure a bit.

The reason I had proposed this question was because I recently received a new Dovo from tss which as most of you know is honed post factory to perfection on a convex hone...

So..jump ahead...I just used the flat balsa.
(Disclaimer, I am a novice at best so please treat me as such. Don't hold back)

I shaved 5 or 6 times with the new Dovo, both wtg and atg. The first few shaves were effortless, even for me when I got not one single weeper I call that a damn good shave. At 5th and 6th it was beginning to pull a tad. I strop before and after every shave on linen and horsehide, still a bit slow but only because I am careful. I took a loupe to it and everything looked fine so I just figured it was time to touch it up a tad on the balsa. No sense in asking if something there went awry, I am meticulous and follow Slash's method to the T.

I am not sure I understand the order of events - did you shave 5 - 6 times on the edge from TSS and THEN start using pasted balsa or immediately start using the pasted balsa?

When I got done I cleaned and stropped and took out the loupe again.

What I observed was that at the very edge I had almost created another tiny edge, as far as I could tell. Now I could be wrong, but I'm pretty sure no tape was used in the previous honing. Therefore I did not tape it and saw absolutely no reason to do so. I never do a dilucot progression, but I don't think this is the same. It passed HHT without a peep though.

When I hone with a convex hone it produces a neater, narrower bevel. The effect is like using tape in terms of bevel width. It is also particularly useful on cheap Dovos where, if they have wonky geometry, it allows you to "follow" the spine curvature. I generally don't bother with paste on Dovos because the edge is great off hone / leather. Where I have used paste after a convex hone I personally have had no issues and as mentioned above, my convex created bevels are more extreme than TSS.

It is possible that you might have created a second bevel behind the bevel from the convex hone. But I think this extremely unlikely because:

1) Efficient as the diamond paste is, if you have followed Slash's instructions I don't believe it would "cut" a new bevel in an edge trailing lap. At most it would polish the bevel shoulders and blend them into the face.
2) If it did occur I think you would get a wavy second bevel behind the edge bevel.
3) I don't think your shaving results reflect a 2nd bevel. micro bevels are stable in my experience. With a coticule unicot pregression the micro bevel holds up more effectively than a single bevel. As @MO1 says, good first pass, bad second pass sounds like a wire / foil edge. Search B&B for discussions and look for magnified examples to compare it with yours. In Slash's method he calls out the pull stroke. Really important step to get rid of this occurrence.
 
So I was waiting to respond until I got a chance to see what is going on up close.
DovoLeftD1.jpg
DovoRightD1.jpg


Not seeing a wire edge...doth my eyes deceive? I'm looking closer at the bevel right above the edge though.
As I mentioned I did use this AS IS honed from TSS for about 5-6 shaves and then touched it up on the freshly lapped and prepped flat balsa 0.5u 0.25u 0.1u . No additional honing has been done yet, and these pics were taken post shave. I am not ruling out user error, only pondering the effects of going from convex to flat with various finishing techniques (if any at all) and how they change a shave experience.

What do you guys see here, other than a tantalizing photo shoot?
 
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