Shakespeare once said

[Acmemfg]

The famous bard advised “to thine own self be true”. Good advice.
For some time I was skeptical of the whole convex hone thing. Today I am here to offer opinion and testimony.
I have had razors honed by some well known masters here: Doc226, Ulrik Beyer (Koraat), Ertan Suer (Rasoir Sabre), Brian Brown (Brown Razor Works); there are others. Many different media have been used: Coticule, Naniwa SS, Arkansas, J nat, Welsh Slate, film, and the list could go on.
I wield a decent hone myself. Hardly in the league of the aforementioned gentlemen but not bad.
However, with all being said and after countless shaves with dozens of straight razors, I can say unequivocally that the best edges I have used to date were those on hollow/extra hollow blades honed on convex stones by Jarrod at The Superior Shave. Yes. They are that good. You may not agree. That’s alright. The world is an arena for various opinions and we should all be grateful that it is. But do remember “to thine own self be true”.
My point here is:
If you have not tried a razor honed by a knowledgeable craftsman who knows how to use a convex hone…try it one time. I’m pretty sure you will like it.
(Mic drop……)

 

[thp001]

I tried it for a while. Sometimes I was absolutely sure it was giving me a better shave, sometimes I couldn't really tell. It depended on the razor and the hones, I had a full synth progression convex and some convex naturals, a Vermont Purple slate, a Thuri, Queer Creek stone. If you have it in you to lap some Arkansas stones or some other stone which is incredibly hard (sintered ceramics) and you think the convex stones work for you that is the best way to go since you will only have to lap once and you're likely set up for life. I hate lapping at the best of times and I hone a fair bit so constantly lapping my synths to keep that correct shape was messy and tedious and as a percentage of my time, more work than the possible difference in shaving performance (when I could feel it). I'm not a honemeister of any description so maybe it was just me.

One can spend an inordinate amount of time, money and effort "chasing the dragon". If you can do that, it can be quite a fun ride, but I'm becoming more and more "low maintenance" as time goes on. As far as shaving goes now, as long as my edge is sharp enough and smooth enough, that's all I care for.

 

[Tomo]

Glad you found a system that works for you. I played around with a lot of different media until I discovered my favourite edge. I’m a self confessed arkoholic.

 

[Empire straights]

Glad you found a system that works for you. I played around with a lot of different media until I discovered my favourite edge. I’m a self confessed arkoholic.

It's hard to beat an edge honed well on an antique black ark. It seems to me there were some old arks quarried back in the day that have a far tighter grain than newer ones. Those old pike and norton hard Arks do something special.

 

[Empire straights]

The famous bard advised “to thine own self be true”. Good advice.
For some time I was skeptical of the whole convex hone thing. Today I am here to offer opinion and testimony.
I have had razors honed by some well known masters here: Doc226, Ulrik Beyer (Koraat), Ertan Suer (Rasoir Sabre), Brian Brown (Brown Razor Works); there are others. Many different media have been used: Coticule, Naniwa SS, Arkansas, J nat, Welsh Slate, film, and the list could go on.
I wield a decent hone myself. Hardly in the league of the aforementioned gentlemen but not bad.
However, with all being said and after countless shaves with dozens of straight razors, I can say unequivocally that the best edges I have used to date were those on hollow/extra hollow blades honed on convex stones by Jarrod at The Superior Shave. Yes. They are that good. You may not agree. That’s alright. The world is an arena for various opinions and we should all be grateful that it is. But do remember “to thine own self be true”.
My point here is:
If you have not tried a razor honed by a knowledgeable craftsman who knows how to use a convex hone…try it one time. I’m pretty sure you will like it.
(Mic drop……)

I ordered a thuringian yesterday that is convexed on one side. That's not why I bought it, I planned on using the flat side and flattening the other but maybe I'll give it a go, it'll be worth playing with id imagine.

 

[MasterOfPups]

To get the full benefit, don't you have to set the bevel on a convex hone, then go through the whole stone progression ? Sounds like a lot of hassle getting all of your stones to the same curvature and keeping them there ?

 

[Jack Goossen]

‘Much ado about nothing’, a thought I have multiple times a day.

 

[Tomo]

I appreciate the theory convex hones and see how they could be beneficial. It achieves the same trick as the unicot method of working on the very edge of the apex but without increasing the bevel angle. It actually decreases the effectiveness bevel angle making the apex a little thinner and sharper. By increasing the radius or even the angle of the blade on the hone you can focus the honing action on a very small area on the tip of the edge.

It is similar to what’s happening with a hollow ground razor. You could argue that the first stage of grinding a hollow ground razor is convex honing. This makes the hollow ground much easier to hone than a true wedge because the contact area at the bevel is smaller. You get much consist contact info the smaller contact patch. Without tape a true wedge is very difficult to hone. The convex stones continue the subsequent stages of sharpening in the same way but with a more gradual progression to flatness.

In my view the theory for convex stones is pretty sound. There would also be major advantages to using a large grinding wheel if you are sharpening on an industrial scale. The process would be a lot faster and easier on the body.

In practice I don’t see any reason to change from flat stones. Getting stones truely flat is hard enough and flat stones have their own set of benefits. In use I don’t see much scope for improvement on the results I get from flat stones either. My edges are as close to perfect as I need them to be for the task of cutting my whiskers. I can see how it would be fun for people to play around with things and push the boundaries of what’s possible though.

 

[David]

Just wanted to share this. (No glitter bombs please).

Peter told me that the huge Escher that I scored recently was never offered to the public or to barbers, only to razor grinders. I just checked it (couldn’t find my straight edge so I used the side of an atoma plate) and it’s convex both ways. Pics aren’t great but best I could do with the kids trying to crawl up my legs.

 

[Empire straights]

Just wanted to share this. (No glitter bombs please).

Peter told me that the huge Escher that I scored recently was never offered to the public or to barbers, only to razor grinders. I just checked it (couldn’t find my straight edge so I used the side of an atoma plate) and it’s convex both ways. Pics aren’t great but best I could do with the kids trying to crawl up my legs. View attachment 1451053View attachment 1451054View attachment 1451054

How thick is it? I've got a small one that's convexed. If you use it that way let me know how you like it. The one I have that's convex is dark blue and really hard and doesn't like to slurry.

 

[David]

How thick is it? I've got a small one that's convexed. If you use it that way let me know how you like it. The one I have that's convex is dark blue and really hard and doesn't like to slurry.

1 1/8 thick.

 

[Steve56]

Try lapping a stone with loose SiC on plate glass, flat marble, etc.

It will have a little crown as Iwasaki said.

 

[Empire straights]

1 1/8 thick.

WOW! I hope I can find a yellow 8" one day.

 

[ErieSurfer]

Try lapping a stone with loose SiC on plate glass, flat marble, etc.

It will have a little crown as Iwasaki said.

When you say 'a little crown', are you referencing convexity like the shape of Dave's Escher?

 

[SilverGeezer]

When you say 'a little crown', are you referencing convexity like the shape of Dave's Escher?

Lapping a stone on glass is like grinding a telescope mirror. One side becomes concave the other convex. If you have done much lapping on a piece of glass, check it with a straight edge, and you will see that it is concave. The surface of your glass plate slowly becomes a parabolic curve.There are people using convex hones that don't know it. Fresh glass for flat, old glass for convex.

 

[ErieSurfer]

Lapping a stone on glass is like grinding a telescope mirror. One side becomes concave the other convex. If you have done much lapping on a piece of glass, check it with a straight edge, and you will see that it is concave. The surface of your glass plate slowly becomes a parabolic curve. There are people using convex hones that don't know it. Fresh glass for flat, old glass for convex.

I thought so, and I think I'm going to use this information to my advantage.

I lapped a bunch of stones last summer and fall, but didn't put a proper straight edge to them until the weather was cold. I found that my stones were a mix of concave, flat, and convex.

I'm going to apply the 'glitter bomb' concept to some of my stones this year with the plate glass I already have on hand.

 

[Steve56]

When you say 'a little crown', are you referencing convexity like the shape of Dave's Escher?

Yep, similar to that.

Here’s my old glass plate.

 

[SilverGeezer]

I thought so, and I think I'm going to use this information to my advantage.

I lapped a bunch of stones last summer and fall, but didn't put a proper straight edge to them until the weather was cold. I found that my stones were a mix of concave, flat, and convex.

I'm going to apply the 'glitter bomb' concept to some of my stones this year with the plate glass I already have on hand.

If you are interested in the math, look up "sagitta". you can calculate the radius of the curve you have ground.

 

[rbscebu]

If you are interested in the math, look up "sagitta". you can calculate the radius of the curve you have ground.

I looked it up and I was taken back to my high school maths days when I last used it.

My work now involves three-dimensional non-regular curvature where we approximate the shape into multiple parabolic three-dimensional surfaces for intergational purposes.