Convex club.

[kohalajohn]

That makes sense. If you feel and hear things happening, then you must be down at the aggressive stage of cutting. The final fine stage of finishing would be merely a light polishing, without feedback.

I think that explains why my black translucent ark has no feedback. It's a dense, fine, finisher. The blade's not crashing through a debris field of slurry, it's just sliding over an oily surface.

Honing on my ark is just an act of faith. The only tell is the shave. I used to be frustrated by that, but I can now understand it better.

 

[Namkcakram]

That makes sense. If you feel and hear things happening, then you must be down at the aggressive stage of cutting. The final fine stage of finishing would be merely a light polishing, without feedback.

I think that explains why my black translucent ark has no feedback. It's a dense, fine, finisher. The blade's not crashing through a debris field of slurry, it's just sliding over an oily surface.

Honing on my ark is just an act of faith. The only tell is the shave. I used to be frustrated by that, but I can now understand it better.

Yes! If you have a Washita it’s the ark equivalent to aggressive slurry, and you can vary your pressure or oil thickness and really hear the changes. It basically sounds like you’re destroying your edge on sandpaper with pressure, and as you lighten to no pressure you keep hearing/feeling a little cutting until eventually you feel very little. Then you move onto the finishing ark and it’s like you describe, basically sliding an edge over oiled glass with an occasional noise or catch on the edge.

I think there are most definitely a few fast AND fine finishers out there in JNAT and Coti land, but personally I only have two Cotis I’d say are fast and leave a really “finished” edge and that one soft nagura that cuts well but sometimes can’t fully finish an edge with one slurry. I have a real love affair with one of my fast Cotis, my tsushima Black nagura, and two washitas to the point where I didn’t hold onto or never purchased a full synth progression at all. I’ve only got a softer 5k and harder 8k from Imanishi(Suehiro), but I have oodles of natural coarse and midranges and a full set of DMTs(had to reorder a few now actually).

 

[kohalajohn]

It's interesting, when you say sliding over oiled glass with an occasional noise or catch on the edge.

that occasional catch, I have been interpreting as a piece or airborn grit getting on the stone. I'll be honing silently, an suddenly hear and feel a catch. I'll run my fingers along the stone trying to find what I'm sure it a piece of grit.

It certainly sounded and felt like that.

but maybe instead it's a bit of foil edge suddenly tearing off, or maybe a microscopic serration on the edge will suddenly catch on a raised pobbly bit of the stone's surface.

 

[Chan Eil Whiskers]

It's interesting, when you say sliding over oiled glass with an occasional noise or catch on the edge.

that occasional catch, I have been interpreting as a piece or airborn grit getting on the stone. I'll be honing silently, an suddenly hear and feel a catch. I'll run my fingers along the stone trying to find what I'm sure it a piece of grit.

It certainly sounded and felt like that.

but maybe instead it's a bit of foil edge suddenly tearing off, or maybe a microscopic serration on the edge will suddenly catch on a raised pobbly bit of the stone's surface.

Sometimes people say the convex stones hit only one spot on the edge at a time. I wouldn't be surprised if the little sounds are one of those spots which needs hitting right then. Not that I'm sure of anything.

Happy shaves,

Jim

 

[kohalajohn]

I'm back on the ark after a jnat vacation.

A very nice gentleman on the forum is loaning me one of his jnats to try. A finisher.

Below is the Wacker, with the convex black translucent ark on the left and the jnat on the right. The ark is upside down so you're seeing the soft side, not the black, oops.

My first entry into jworld. It is a learning curve. First I used too thick slurry and took the blade backwardward. Then learned to dilute with lots of water and finish with clear water. Better.

I would have good shaves, then not so good shaves. Got lots of helpful advice from the owner.

I must admit I got a bit frustrated with the hit and miss nature of it. I know it's not the stone, it's the honer.

But an ark isn't hit and miss. It's always hit. Yes, ok it's slow, so you have to hone more often. But I'm ok with that. I think a finisher should be slow.

So yesterday I honed it on the ark, with ballistol and light pressure for fifty laps.

Very nice shave. Sharp and comfortable.

Not as sharp as a feather in a shavette of course, but not unforgiving and bitey either. A feather in a shavette is like a girlfriend I once had. Whew.

And again this evening, on the ark, and again, sharp and comfortable.

I know I'll try jnats again. I can see the hobby attraction is when you finally get it right, that will feel very satisfying.

Jnats feel like golf. You're pissed off and about to quit, then you hit a great shot and you think you love the sport. And repeat.

Aloha

 

[147_Grain]

I've got a 6x2 combo convex ark on the way from TSS. I think it has a date with some old American and English steel this coming weekend, before I try it on a Friodur. I used to have a thin-ish natural combo LV coti that I used for razors with imperfect geometry, this might well take its place.

 

[Chan Eil Whiskers]

I've got a 6x2 combo convex ark on the way from TSS. I think it has a date with some old American and English steel this coming weekend, before I try it on a Friodur. I used to have a thin-ish natural combo LV coti that I used for razors with imperfect geometry, this might well take its place.

Congratulations on joining the convexed Ark owners group.

What lubricant are you planning to use with this stone?

I've not used this size DCA but I believe it should be very nice.

Happy shaves,

Jim

 

[147_Grain]

With my other ark (a trans from Dan's), I've had success with lather or diluted glycerin, so probably one of those. The feel on water was just awful when I tried it and mineral oil seemed too thick and additionally was a pain in the butt to clean off things if it dripped. I haven't tried diluted ballistol.

 

[Chan Eil Whiskers]

With my other ark (a trans from Dan's), I've had success with lather or diluted glycerin, so probably one of those. The feel on water was just awful when I tried it and mineral oil seemed too thick and additionally was a pain in the butt to clean off things if it dripped. I haven't tried diluted ballistol.

Thanks.

I've not tried glycerin. Most things I've tried have worked well enough but I like the Ballistol water mixture as well as or better than anything else I've tried. Probably it's very subjective (other than cleanup).

Happy shaves,

Jim

 

[147_Grain]

The 6x2 convex combo arrived in the mail today, and I couldn't wait to use it. I was too lazy to fetch my bottle of glycerin from the basement (I keep it with the soapmaking supplies), so I honed a quasi-NOS Hoffritz straight I got as part of a package with a strop a few years ago on Ebay that I had never gotten around to using on plain water; as it was it would catch but not pop arm hairs, and I killed the edge on glass before starting.

The feel on the soft side was surprisingly almost velvety. The feel on the trans side was much better than I remember trans arks on water feeling. After honing and stropping it was doing an OK job of popping arm hairs about 3/8" from the skin, so I went ahead and shaved. It felt very mellow on the skin, like a coti edge on the high end of coti keenness. I only went ATG from the jawline up and it felt a little tuggy in spots, but when the aftershave was dry I was surprised to find that I had about a BBS- and zero irritation. Obviously I'm not "there" yet, but IMO not bad for a first outing.

I hope with continued use to determine whether either side of the stone has any tells. I didn't see undercut on the trans side when honing on water, but I may have simply stopped prematurely. I've got a few Brit razors with mild warps (a J.G. Dodd Magbel, and a W&B Celebrated Extra-Hollow) that I'll hone up over the next week as practice with the stone.

 

[Chan Eil Whiskers]

The 6x2 convex combo arrived in the mail today, and I couldn't wait to use it. I was too lazy to fetch my bottle of glycerin from the basement (I keep it with the soapmaking supplies), so I honed a quasi-NOS Hoffritz straight I got as part of a package with a strop a few years ago on Ebay that I had never gotten around to using on plain water; as it was it would catch but not pop arm hairs, and I killed the edge on glass before starting.

The feel on the soft side was surprisingly almost velvety. The feel on the trans side was much better than I remember trans arks on water feeling. After honing and stropping it was doing an OK job of popping arm hairs about 3/8" from the skin, so I went ahead and shaved. It felt very mellow on the skin, like a coti edge on the high end of coti keenness. I only went ATG from the jawline up and it felt a little tuggy in spots, but when the aftershave was dry I was surprised to find that I had about a BBS- and zero irritation. Obviously I'm not "there" yet, but IMO not bad for a first outing.

I hope with continued use to determine whether either side of the stone has any tells. I didn't see undercut on the trans side when honing on water, but I may have simply stopped prematurely. I've got a few Brit razors with mild warps (a J.G. Dodd Magbel, and a W&B Celebrated Extra-Hollow) that I'll hone up over the next week as practice with the stone.

Nice. I'll be interested as you continue.

There is some undercut with Ballistol and water, but I'm not saying it is 100% useful. I also notice a bit of sticking sometimes, but, again, not terribly useful.

Determining when I've max'd out the edge and gotten it as sharp as it can get seems to me to be a matter of shave testing and then returning to the stone and more shave testing, etc. Finally, I know it's max'd out, but it's a process.

Actually, most of the time I get it to where it's "sharp enough" to fully please me. It may or may not be actually fully max'd out but it's so close I'm satisfied and stop the process. I'm lazy.

Happy shaves,

Jim

 

[lightfoot]

As soon as my SIC powder gets here I’ll be preparing my own concave lapping plates in an attempt to give a few stones Convex surfaces. And while I’m not up to the task of doing this to my Arkansas stones I have a few others that I’ll use for the experiment. I’ll post the results soon.

 

[bluesman 7]

As soon as my SIC powder gets here I’ll be preparing my own concave lapping plates in an attempt to give a few stones Convex surfaces. And while I’m not up to the task of doing this to my Arkansas stones I have a few others that I’ll use for the experiment. I’ll post the results soon.

 

[lightfoot]

I convexed one of those cheap $20 interweb hones by hand just to try it out. The hone is garbage but it does give me an idea about the tactile experience. Very easy to isolate specific areas for sure. I’ll need to be very mindful of trying to keep my strokes continuous & even on blades with no issues because too much time in a given section of the blade can cause uneven wear. But that’s just a matter of practice. I definitely favor this setup but it’s just personal preference.

 

[lightfoot]

One thing for everyone to keep in mind is that the advantage of this type of hone is limited to hollow ground razors. The idea is that a flexible hollow ground razor will flex at the edge as it passes over the spherical surface ever so slightly much like how the edge will flex while being gently pushed on a thumbnail. Jarrod Had suggested that it isn’t advisable to use this type of hone on wedge razors or other razors that aren’t flexible at the edge. Blades with heavier grinds should probably continue to be honed on a flat surface. Thanks

 

[Namkcakram]

That’s silliness. Unless the hollow grind in the blade is exceedingly shallow IE “true wedge” the stone would work just the same but slower.

 

[lightfoot]

That’s silliness. Unless the hollow grind in the blade is exceedingly shallow IE “true wedge” the stone would work just the same but slower.

I can only reiterate that my source was from Jarrod himself...
But ultimately it’s user discretion.

 

[Namkcakram]

I can only reiterate that my source was from Jarrod himself...
But ultimately it’s user discretion.

I’m just saying I’m an actual engineer- and as Jarrod suggests I 100% see the benefit of convex stones honing razors that may have slightly wonky edges.

As an engineer I’d also pose this question: how (meaning in what axes) would you expect the edge of a straight razor to deflect, if it were actually warping as it runs over the stone? The answer is very obviously that it would have to deflect in multiple axes to “flex as it passes over the stone”, since the edge is literally the edge of a series of planes geometrically and the edge of a single sheet of steel. If the blade is deflecting around the stone, it MUST deflect in the axis whereby the cutting edge is torqued upward twisted away from the spine and the stone surface... meaning you would not be actually honing at the cutting edge itself.

This deflection does not happen to any significant degree, as proven by the fact that we ARE reaching the cutting edge of the razor. Therefore deflection or lack of deflection is not a consideration in this application.



Now if you have a “true wedge” or close to it, there could be a situation where the hollow of the razor either is a larger radius than that of the stone (unlikely since I’ve never heard of a ~33ft+ dual grinding wheel setup), or the razor face is perfectly flat meaning the convex stone is hollowing out the center of the blade rather than honing. But for any commonly available “heavy grind” razor, the key word is “grind” which implies a wheel smaller than the radius of one of jarrods stones, meaning the stones work just fine.

But don’t ask me, I don’t own any stones I can’t hone woodworking tools on, we can ask any of the people on the forum who own jarrods stones and I’m quite sure we’d find a few stories of successfullly honing a heavy grind razor or two.



I’m not posting this to argue with anyone, I’m posting because I do see the value of these stones and I wouldn’t want someone who’s primarily a wedge fan to be deterred.

 

[lightfoot]

I cannot respond to your points from an engineering perspective as I am not an engineer myself. All I can offer is the explanation that I was given & that was that the convex surface was most likely adopted as a means of refining fully hollow ground razors as they represent the overwhelming majority of razors produced by the grinders that are a part of the Grinder’s Guild in Germany. While it’s not my place to tell anyone on this forum or elsewhere that they should or shouldn’t use stones prepared with a convex surface, I feel that those considering the purchase of these stones (or those like myself who are about to prepare one) that they may not be an appropriate honing solution for every type of razor geometry.

 

[147_Grain]

I just honed a pre-1891 Wade & Butcher with at most a quarter hollow grind on my little 6x2 combo convex ark. It treetops pretty well now, I'll find out tomorrow morning how it shaves.

I bought this razor three or four years ago and never put an edge I was satisfied with on it before now because it is somewhat warped and I got a case of the vapors about how much steel I was removing on the D8F before I got the thing completely straightened out.

It felt weird as heck stropping the thing. I'm used to nice thin flexible bellied hollow grinds, the change in tactile feedback and the dead sound were kind of off-putting. It felt fine on the ark beforehand, though.