Convex club.

[kohalajohn]

Yes, Bluesman, but...

I may be wrong here, but a smile is a different thing that what I'm talking about. The smile on your razor is just the edge protruding straight out in a belly shape. That's not a warp. The smiling razor is still flat all along the plane that rests on the hone.

You put a smiling razor on a piece of flat glass and add water, the flat razor will get stuck to the glass. You will have just as much stiction as if it was not smiling.

But Jarrod's Ark is creating a curve along a plane that the flat plane of your smiling razor is trying to rest on.

So far I have found no stiction. And that conforms to the theory. You start your stroke heel leading, with only the heel touching the stone. And way back down the curve of the stony hill, the toe is hanging up in the air.

I'm exaggerating this to make the point.

By the time you have gone up and down the hill on the other side, the toe is now touching the stone and the heel is up in the air. Air is under more than half of the razor, so no vacuum, no suction.

When you do an x stroke on a convex, this just happens on its own. I'm not doing it myself. The hill does it. I am now starting to sense the pressure starting at the heel and as I stroke, the pressure moves down the razor to finish on the toe. Like how you can feel the edge of a chef's knife running down a chef's steel as you stroke.

And here's the weird thing. Maybe the lack of stiction doesn't matter. On flat stones Stiction tells you all is good. Your hone is flat, so hooray, you don't need to lap it. Your razor does not have a warp, so hooray you don't need to manually do a rolling x. The tell of stiction is my friend on my flat stones.

But on a convex, you don't need to be told about flatness because it's deliberately not flat and you're not going to lap it anyway. And you don't need to be told about a warp, because a warp won't matter, the edge is running along the hone point by point.

 

[kohalajohn]

Craftsmen in Yasuki at the annual street fair. Yasuki also pronounced Yasugi is the home of Hitachi Steel boutique steel division. The whole town is about steel and people from all over the area bring their knives for sharpening to this fair.
Togi or sword sharpeners in Japan also use convex stones as they polish/sharpen 5mm of steel at a time. These guy below are sharpening portions of the blade as they go from heel to toe on synthetic stones. For convex blades the principle if fine but the skill of the worker is the key to keeping the edges gentle heel to toe profile. With aggressive stone in the 1,000 grit range lots of steel can be removed fast.

Alex

Cool photo Alex.

I see their little naguras stacked in front of the hone. I wonder how they maintain convexity on a soft synthetic? Perhaps they use the naguras to circle the periphery.

I tried doing that on a synthetic stone, in the past. You have to do an awful lot of circling.

If someone had a convex granite slab clamped on to a variable speed pottery wheel and a bag of grit, he could set up at the fair and fix up everybody's convex hones for them.

 

[bluesman 7]

The smile on your razor is just the edge protruding straight out in a belly shape. That's not a warp. The smiling razor is still flat all along the plane that rests on the hone.

You put a smiling razor on a piece of flat glass and add water, the flat razor will get stuck to the glass. You will have just as much stiction as if it was not smiling.

No, a symmetrical smile can not lie in a plane. 'Two planes intersect as a straight line' Euclid. The edge and spine form a truncated conical section on a symmetrical smiling razor. I keep specifying symmetrical because it would be possible with a warped smiler to have one of the sides lying flat on a hone, but the other side could not in this case.

If you take a dinner plate and tip it up on a table until a spot near the edge of the plate touches the table. The plate is now contacting the table in two places, a spot near the rim of the plate and a spot on the ring on the bottom of the plate. This is the same geometry of a smiling razor except on the razor the cone is much flatter. Flat enough that most people do not recognize that the edge and the corresponding contact points on each side of the spine lie in a conical sections.

This is why you have to roll to hone a smile.

 

[bluesman 7]

If someone had a concave granite slab clamped on to a variable speed pottery wheel and a bag of grit, he could set up at the fair and fix up everybody's convex hones for them.

Fixed that for you.

 

[kohalajohn]

Correct on the concave granite slab correction..

Also correct on the smile. Yeah, I see now that the spine lifts up the smile. The belly of the smile touches the hone, the heel and toe of the smile are up in the air.

Interesting that you can still get stiction on a smiling razor, then.

I thought perhaps its because the soft thin edge will flex under pressure and will be pushed down so that its whole length is sliding underneath the water.

But no, that can't be right because in that case you would not have to roll the razor. You'd just push down hard and make it behave like a non smiling razor.

Maybe the bit in the middle that is touching, is wide enough to create the vacuum effect.

So then why am I not getting stiction on a convex hone? Maybe the bit touching is narrower than the bit touching when it's a smiling edge.

Or maybe one day I will get stiction on this hone.

 

[Namkcakram]

This statement surprises me. I get stiction on smiling razors. Same small contact area.

I thought the same thing. And in the video honing the ballistol mix, it looks like a decently wide swath of solution is still being undercut to some degree... more or less equal to a smiling fat Sheffield blade on a flat hone.

Maybe stiction doesn’t make a noticeable impact until the spine and bevel are both worn enough into a slight hollow grind to match the stones arc? I’d imagine depending on the razor design the spine could take a few honings to get all the way there? I’ve got plenty of examples of razors with wider spine wear facets than bevels.

 

[kohalajohn]

In my ballistol video, yes, you could see the solution being undercut, but I felt absolutely no stiction.

Maybe when the bevel has become hollow to match the stone's curve.

Or when I use a razor that is very flexible.

We'll see. I'll let you know.

 

[bluesman 7]

I suppose that the stiction on a smiler is more subtle.

 

[Citizen404]

I bought a set of convex stones as well. I've used them 3 times over the week. The first two razors I tried were gold dollar types with thick uneven bevels and gnarly spines. These were usable but not great. (I like to have a few razors around to give away if the.subject ever comes up.) I used a rolling x, and watching the Ballistol move up the blade I honed for a few minutes. After stropping I was surprised to get tree topping across my arm easily. Both of these razors gave me very smooth comfortable shaves.

The third razor was a nice Dovo, and only using the finishing stone and stropping I got an excellent shave.

The convexity is very subtle. I see why Jarrod suggests using a straight edge to see it. Using these hones don't seem a while lot different. The convexity seems to make it very easy to get good results. I'm not super skilled at honing, I have only ever used stones and don't go for the nth degree with films, pastes, etc. The edges I'm getting are mirror polished, and under a loupe seem cleaner than coticule edges.





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[Chan Eil Whiskers]

I've now used the my 8x3" Double Convex Combo Ark for the first time. Here's a link to my honing and shave report.

It went reasonably well. Determining when to stop is the big issue. I need more experience. I like the hone.

Happy shaves,

Jim

 

[kohalajohn]

Glad you're using it.

I found it got better with use. Soon you see the white Ballistol move from the heel down to the toe as you go.

And no stiction. And it won't tell you when it's done. You have to treetop. Like pasted balsa, you just learn that it takes say x laps and then you just do that.

I found that it's a bit easier than a coti and a bit sharper than a coti. Not crazy sharp like diamond pasted balsa.

I see you used one type of lube on the bevel and then ballistol on the finish. I just used ballistol for both. It washes off easier.

Have fun.

 

[Chan Eil Whiskers]

Glad you're using it.

I found it got better with use. Soon you see the white Ballistol move from the heel down to the toe as you go.

And no stiction. And it won't tell you when it's done. You have to treetop. Like pasted balsa, you just learn that it takes say x laps and then you just do that.

I found that it's a bit easier than a coti and a bit sharper than a coti. Not crazy sharp like diamond pasted balsa.

I see you used one type of lube on the bevel and then ballistol on the finish. I just used ballistol for both. It washes off easier.

Have fun.

Thanks. You are responsible for the whole thing being the successful enabler trailblazer and explainer you are.

I've found the coti really easy to use. I must have just gotten lucky and also read just the right stuff for the particular coticule Jarrod sent me. Same with the Zulu Grey (on one use). I think Arks in general are not very easy stones to use, but this one seems easier than the other two I have. Of course, I have the advantage of having fooled with them successfully.

In what way is this stone easier that the coti for you?

I'm pretty sure the only really "constant" with the lubes on the Arks is to use oil on the softer Arks. And, there's a gentlemen who collects wild Arks and has all his life who uses only water even on them (if memory serves me). My best finishing edges on the flat Arks so far have been with synthetic oil. I've tried various oils. Many are too thick for me to feel what's happening (and they may give the blade too much cushion).

The Ballistol and water seems great, too, and has the visual advantage. I bet you'd like the oil I pictured. It doesn't take much of it. The dropper is pretty precise.

I have now four Arks. Three are finishers. All three are significantly different from one another although I'm not sure exactly how to describe how they differ. Two are translucent;" this black translucent and my Norton Hard Translucent; they feel different in use, too. I'm not far enough along to really know this, but my impression so far is this new stone feels more like the Hard Black than the Norton, but I like the feel of this one better than either (maybe).

It's not like I have much experience with any stones. Only about 170 straight razor shaves doesn't give much honing experience. Plus, I don't just love honing like some guys and am fine keeping things going with the pastes and more so with good stropping. I'm whatever the opposite of an old hand is (but I can get a good sharp edge so I'm not a total greenhorn I guess). Maybe I'm a first week journeyman or in journeyman orientation. Who cares? Not me. Sharp and comfortable are the only thing that matters, right.

Anyway, it's a lovely stone. I'm glad I have it. Thanks for helping me understand how to begin with it.

If you were doing it over knowing what you know would you perhaps buy the smaller convexed stone? I'd like to say I would (it's probably all anyone needs in a convexed Ark + about a third the money) but I'd buy the big one again. I think they're going to become rare and I'd hate to always wonder if I missed the opportunity and should have taken it + maybe I'll come to appreciate the real estate. Still, I'd like to have the small convexed double, too. I think it might suit my honing style better. Down the road I might sell the big one, but, if I want to try that I'll for sure buy the small one first so they overlap.

I've sold stuff before and had seller's remorse. I've bought back stuff I sold, too, and then had buyer's remorse or realized why I sold it.

Great stone I think, but I need more time to confirm my initial impression. Interesting stone. Interesting discussion surrounding it, too, but mostly beyond me.

Happy shaves,

Jim

 

[Chan Eil Whiskers]

The synthetic oil washes off in seconds with water water and soap. It's a piece of cake.

 

[Citizen404]

In what way is this stone easier that the coti for you?

For me, it just works. I can get a very nice shaving edge with a coticule, but I have to work at it and it's not as repeatable. With the coticule I strive to use less and less pressure with my strokes over time. I'm happy when I am getting good hht results. (My wife has fine curly colored hair, hht is difficult.) I have never gotten a razor to cut hair off my forearm held above the skin.

The convex stone gave me the finest edge I've ever achieved without even trying, and quickly. The shave is terrific, and I'm shaving exclusively with straights now.

I suspect if these stones sell, there will be other 8x3 stones. I would agree, it's probably not necessary. I think it's nice to have, though.



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[kohalajohn]

The 8x3 size is not needed. But whatever, it's still cool.

I would rather have it than a 6x2. 2 is a half inch too narrow. 2.5 is perfect. I don't know if he's going to make that size.

On the 8x3 the half inch on the left is not used.

The convex Ark, for me, is easier than the coti in that with the coti I have to frequently keep it under running water to avoid slurry buildup. For fine finishing I don't want any slurry. But that's not a big deal.

And also I don't need to check for dishing or think about lapping. I am still both doubting/amazed by that. It's like someone sells you a house plant and says you never have to water it. Really?

 

[Chan Eil Whiskers]

For me, it just works. I can get a very nice shaving edge with a coticule, but I have to work at it and it's not as repeatable. With the coticule I strive to use less and less pressure with my strokes over time. I'm happy when I am getting good hht results. (My wife has fine curly colored hair, hht is difficult.) I have never gotten a razor to cut hair off my forearm held above the skin.

The convex stone gave me the finest edge I've ever achieved without even trying, and quickly. The shave is terrific, and I'm shaving exclusively with straights now.

I suspect if these stones sell, there will be other 8x3 stones. I would agree, it's probably not necessary. I think it's nice to have, though.

Thanks. Helpful information. I'm hoping my later efforts yesterday (second go round on the Double Convex) were better. Will find out soon enough.

The 8x3 size is not needed. But whatever, it's still cool.

I would rather have it than a 6x2. 2 is a half inch too narrow. 2.5 is perfect. I don't know if he's going to make that size.

On the 8x3 the half inch on the left is not used.

The convex Ark, for me, is easier than the coti in that with the coti I have to frequently keep it under running water to avoid slurry buildup. For fine finishing I don't want any slurry. But that's not a big deal.

And also I don't need to check for dishing or think about lapping. I am still both doubting/amazed by that. It's like someone sells you a house plant and says you never have to water it. Really?

Thanks. Makes sense.

On the coti I sometimes use my patented Dilucot Oil Honing method. If I use water I wash the slurry off with a spray bottle towards the end. It's easy enough.

Happy shaves,

Jim

 

[Chan Eil Whiskers]

This is a not so good report. Link.

I'll persist, but gotta figure out how to change something.

Happy shaves to you,

Jim

 

[kohalajohn]

Jim, this is something I see a lot on this forum.

Some sharpening systems work great for some guys and they swear by them. Other guys don't like them at all and insist that only their systems are the good ones.

I think that's why the honing forum is known (more so in the past) as the place where real arguments blow up. Where the mediators have to step in.

I think the difference is technique. Some guys just naturally or through luck, happen to nail the technique that happens to work with that system. Doc226 has found that he is just made for jnats. Or over the years he made himself into someone who does it just the way jnats want. He may be awful on other methods.

Slash wanted to a pass around of his diamond pasted balsa strops, to show that it was a perfectly clear system that would work for everyone. To our surprise, some of the razors eventually went south. Some guys' technique just didn't match up with the system.

Not saying anybody was doing anything "wrong". It seems to be that systems work with certain hand techniques, pressure, god knows what.

And eventually a fella will try a system that coincidentally just happens to work with how his hands and fingers and eyes work. And he thinks that's the best system. Well it's not. It's just a match, is all.

Just a theory.

Tomorrow maybe try a different razor. And randomly adjust some technique. Pressure, number of laps. Maybe do it in a way that your brain says is "wrong".

And if not, you'll have an easy time selling that stone.

 

[Chan Eil Whiskers]

Jim, this is something I see a lot on this forum.

Some sharpening systems work great for some guys and they swear by them. Other guys don't like them at all and insist that only their systems are the good ones.

I think that's why the honing forum is known (more so in the past) as the place where real arguments blow up. Where the mediators have to step in.

Slash wanted to a pass around of his diamond pasted balsa strops, to show that it was a perfectly clear system that would work for everyone. To our surprise, some of the razors eventually went south. Some guys' technique just didn't match up with the system.

Not saying anybody was doing anything "wrong." It seems to me that systems work with certain hand techniques, pressure, god knows what.

And eventually a fella will try a system that coincidentally just happens to work with how his hands and fingers and eyes work. And he thinks that's the best system. Well it's not. It's just a match, is all.

Just a theory.

Tomorrow maybe try a different razor. And randomly adjust some technique. Pressure, number of laps. Maybe do it in a way that your brain says is "wrong".

And if not, you'll have an easy time selling that stone.

Lots of smart stuff here, sir. I like your theory.

Some guys just naturally or through luck, happen to nail the technique that happens to work with that system. Doc226 has found that he is just made for jnats. Or over the years he made himself into someone who does it just the way jnats want. He may be awful on other methods.

I'm not at all sure I can master all stones or honing systems, but most of the time I've had an interesting time of it. Sometimes it's been easy for me (coticules so far, Zulu Grey so far). Sometimes it's been not so easy but worked out pretty well pretty fast (Norton Translucent Ark). Sometimes it's been fun, but not always.

The jury is still out on how I mesh with the Double Convex 8x3.

As we've discussed there are hobby aspects at play, but the bottom line for me is also getting a good shave out of the razor (ultimately). I'm ready, willing, eager, and able to try to learn the stone. I'm willing to sell the stone if I fail to learn it or don't mesh with the stone.

Thanks.

Happy shaves,

Jim

 

[Dzaw]

Jim, this is something I see a lot on this forum.

Some sharpening systems work great for some guys and they swear by them. Other guys don't like them at all and insist that only their systems are the good ones.

I think that's why the honing forum is known (more so in the past) as the place where real arguments blow up. Where the mediators have to step in.

I think the difference is technique. Some guys just naturally or through luck, happen to nail the technique that happens to work with that system. Doc226 has found that he is just made for jnats. Or over the years he made himself into someone who does it just the way jnats want. He may be awful on other methods.

Slash wanted to a pass around of his diamond pasted balsa strops, to show that it was a perfectly clear system that would work for everyone. To our surprise, some of the razors eventually went south. Some guys' technique just didn't match up with the system.

Not saying anybody was doing anything "wrong". It seems to be that systems work with certain hand techniques, pressure, god knows what.

And eventually a fella will try a system that coincidentally just happens to work with how his hands and fingers and eyes work. And he thinks that's the best system. Well it's not. It's just a match, is all.

Just a theory.

Tomorrow maybe try a different razor. And randomly adjust some technique. Pressure, number of laps. Maybe do it in a way that your brain says is "wrong".

And if not, you'll have an easy time selling that stone.

That is very well thought out, sage advice.

To follow it up, might I ask;

Aside from trying each and every one to find which ones are a match, is there a roadmap to finding what works well for you?

Something like this:

Since you found approach / stone n to be "ok", but not "great", and you found approach/ stone a to be terrible, that means stone y should work beautifully for you...

Or some other sort of comparing ones experience with a couple of approaches to determine an optimal next try?

Or is it all just "Try this, see if you like it, if not, there's always those hundred others you could try...".