Convex balsa strop?

[MO1]

So I was waiting to respond until I got a chance to see what is going on up close.View attachment 1117889View attachment 1117890

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?

That does indeed look like a wire edge. Or a wire edge used. That white line at the very apex suggest a wire edge and small chips broken off from it.
That won't be comfortable to shave with, it has to be rehoned.
I would probably kill the edge by dragging it lightly on the side of the stone, then bring it back on 6-8k. Or on a slurried jnat.
Getting rid of the wire edge is not that hard(light laps on your finishing stone or on a jnat with light slurry), but a used wire edge has small chips in it which needs to go.

 

[Xijukx]

That does indeed look like a wire edge. Or a wire edge used. That white line at the very apex suggest a wire edge and small chips broken off from it.
That won't be comfortable to shave with, it has to be rehoned.
I would probably kill the edge by dragging it lightly on the side of the stone, then bring it back on 6-8k. Or on a slurried jnat.
Getting rid of the wire edge is not that hard(light laps on your finishing stone or on a jnat with light slurry), but a used wire edge has small chips in it which needs to go.

In these photos I'm shining another light from the front to illuminate the edge. I can post photos of just the direct light source too though if it makes a difference.

 

[MO1]

I don't think it will make a difference, I think the photos are great actually. Just the apex being illuminated like that is most certainly a wire edge.
No reflection of where the small chips are suggest that even more.

 

[Xijukx]

Again, with direct light only...

And with a light illuminating the edge...

Now it is exactly like this on both sides, not folded over one way or the other. I am honestly more inclined to think along the lines of a microbevel as previously suggested. I have not yet honed this one myself, but i will say all of my edges will light up when illuminated and they are most certainly not all wire edges.


Here is an example of a different blade I honed:
one source of light...

And edge illuminated...

I am going to take more pictures after re Methoding the edge ending with pull strokes to see if it improves or remains. I know I could just hone it, but I am having fun with an experiment of sorts.

 

[Xijukx]

After experimenting with the convex honed edge a bit, I have personally come to a few deductions:

1. A convexed edge IS a thing. If you take a convexed edge to a flat surface you WILL see that it only makes contact with the apex and at the bevel directly behind the edge. That means to me there is a slight degree of a more acute angle going on geometrically, purely based on shape of the cutting edge. In principle this should provide a keener degree of sharpness, in practicality though you would have to have a separate range of hones that are convexed to properly maintain any edge you have "converted". Or one all rounder I guess.

2. As for touching up the convexed (or rather concave) edge on balsa wood, even though the wood IS soft I personally found that when I used the balsa on the convexed edge without a great deal of pressure it was indeed creating a micro-bevel. Now that is not necessarily a bad thing, just not the result I was aiming for. If I were to do this to my liking I would in fact probably consider convexing my balsa blocks to properly make absolute contact along the length of the edge without needing more pressure than I am comfortable with exerting on the edge.

3. To support my theory I took the advice of the man who in fact honed the razor, and acquired a paddle strop with a slight convexity to it. I then loaded each side with diamond paste and stropped. The results were much better.

4. I flattened the edge. I get fine results with all of the hones I currently own and let's face it... I'm not convexing any of my escher thuringian stones any time soon.

In conclusion, this may be stuff every veteran wet shaver already knows. But for me I need to learn through my own experiences to have an adequate understanding of the physics at play. Your experience may differ.

 

[bluesman 7]

In these photos I'm shining another light from the front to illuminate the edge.

In my way of thinking that is the best way to illuminate...unless you are are trying to hide your problems.

 

[Xijukx]

In my way of thinking that is the best way to illuminate...unless you are are trying to hide your problems.

Agreed. Although I have gotten clearer edge illuminations from indirect light at times.

 

[global_dev]

After experimenting with the convex honed edge a bit, I have personally come to a few deductions:

1. A convexed edge IS a thing. If you take a convexed edge to a flat surface you WILL see that it only makes contact with the apex and at the bevel directly behind the edge. That means to me there is a slight degree of a more acute angle going on geometrically, purely based on shape of the cutting edge. In principle this should provide a keener degree of sharpness, in practicality though you would have to have a separate range of hones that are convexed to properly maintain any edge you have "converted". Or one all rounder I guess.

2. As for touching up the convexed (or rather concave) edge on balsa wood, even though the wood IS soft I personally found that when I used the balsa on the convexed edge without a great deal of pressure it was indeed creating a micro-bevel. Now that is not necessarily a bad thing, just not the result I was aiming for. If I were to do this to my liking I would in fact probably consider convexing my balsa blocks to properly make absolute contact along the length of the edge without needing more pressure than I am comfortable with exerting on the edge.

3. To support my theory I took the advice of the man who in fact honed the razor, and acquired a paddle strop with a slight convexity to it. I then loaded each side with diamond paste and stropped. The results were much better.

4. I flattened the edge. I get fine results with all of the hones I currently own and let's face it... I'm not convexing any of my escher thuringian stones any time soon.

In conclusion, this may be stuff every veteran wet shaver already knows. But for me I need to learn through my own experiences to have an adequate understanding of the physics at play. Your experience may differ.

i’m playing around with this currently and i have a hard time thinking that compressible materials like balsa and leather would be suitable but it sounds like you found the leather to be ok.

my convex hones are subtle like TSSs maybe even more subtle, i havent seen his outside his vids and measurements.

i dont normally use balsa but i have a block lying around that i could convex and apply some diamond spray.

is the leather really thin?

 

[Xijukx]

i’m playing around with this currently and i have a hard time thinking that compressible materials like balsa and leather would be suitable but it sounds like you found the leather to be ok.

my convex hones are subtle like TSSs maybe even more subtle, i havent seen his outside his vids and measurements.

i dont normally use balsa but i have a block lying around that i could convex and apply some diamond spray.

is the leather really thin?

This is the one I used. It is pretty stiff and supported by a foam padding. I had wedges inserted between the wood to stop it from flexing inward under pressure and to give it more of a bow in middle. Otherwise I found it would almost plateau once I got towards the center, defeating the intended purpose.

 

[global_dev]

Interesting, so this was convex across both xy planes? I have some Smaller leather strop pieces i can try also, maybe i can find a suitable piece of wood for underneath with using foam or gaps.

 

[Xijukx]

I did my best to get that piece to kind of reverse cup, by wrapping it with an old t shirt so it was tight on the corners. The leather was stiff enough to hold form... For a few seconds at least. Not the best attempt or solution but I felt like it was at least making more contact with the edge when I stropped. I still honestly feel like there was some compression/rebound effect of the surface of the leather though if I added any significant pressure. It was many light strokes until I saw a marked improvement over the previous results.

In the end I still just was not satisfied that I had came up with reproducible results for effectively touching up the convex honed edge, at least not as reliably as I can with flat hones. If you have better luck than I did I would like to hear any input or findings you come up with.

 

[global_dev]

It’ll be hard for me to be of that much help as i dont regularly use pastes or sprays for effective touch up. I only have 1.0, 0.5, and 0.25 diamond spray and no pastes but i’ll Give what i have a try

 

[global_dev]

Hopefully you can make out the convexity

tbh, its very slight but it matches the hones. I’m waiting for .25 spray to dry before trying it out.

 

[Xijukx]

Hopefully you can make out the convexity

tbh, its very slight but it matches the hones. I’m waiting for .25 spray to dry before trying it out.

Very nice! Seeing as how you are carrying on with where I left off, it is only fair of me to offer some diamond paste. If you want to try it out I can send enough to at least cover the block once or twice. I have 0.5 0.25 & 0.1

And the experiment lives on!

 

[global_dev]

I just convexed an 8x3 piece of pine. I am going to see if i can glue a piece of strop leather to it without issue.

i was also thinking of the variations

• Convex base/flat leather
• Flat base/convex leather
• Convex base/convex leather

 

[global_dev]

@Xijukx

the 8x3 was looking a bit too big from what i needed, so I made a 5x1.5 out of same pine. i lightly sanded the leather bottom, but kept it flat and glued it down. you can definitely feel the convexity, even if you can't see it that well. feels nice to strop with also as i've already given it a couple of laps.

 

[Xijukx]

@Xijukx

the 8x3 was looking a bit too big from what i needed, so I made a 5x1.5 out of same pine. i lightly sanded the leather bottom, but kept it flat and glued it down. you can definitely feel the convexity, even if you can't see it that well. feels nice to strop with also as i've already given it a couple of laps.

Looks good. How stiff is the leather? The convexity is very subtle but I guess my overall point will still be true, does it make better contact along the length of the entire edge? I was using a microscope to check the striations from the diamond pastes, but you should be able to see with a loupe if you have one.

 

[global_dev]

The leather wasnt super stiff nor pliable, but it molds to the base.

i have a bunch of “junk” including usb microscope, handheld 60-120x and a 30x/60x loupe to check.

 

[Xijukx]

I sent that out yesterday. It is by TechDiamondTools, they sell on Amazon for 10$ or less a tube. They have all different grits and in different diamond concentration, I think these 3 are the highest grits in 10% concentration. I have found it to be great quality and the tube will last a lifetime probably.

 

[global_dev]

Finally applied the .1 to the convex leather. Funny how trying to apply and use these makes me feel like a newbie.

I let the paste dry and then stropped the concave edge. The edge off it was pretty nice.

So i need to use these pastes more or less for every shave?