Convex club.

[Basil]

Seems like this thread has been interesting lately and I’ve kinda missed out.


I bought one of these convex arks a while back. It’s a decent stone nothing spectacular. I lapped the bottom of the stone flat and ended up using that side more often to be honest. I started getting much better results from my jnat though and completely stopped using the ark.

 

[Chan Eil Whiskers]

I'm not sure anyone is actually critical of the hones other than to say they are not necessary and CAN lead to geometry problems if solely using them.
The "theory" from members with a lot of experience does not have to be from using said stone.
It is the theory of honing razors.
We can understand how the hone will work without purchasing one even though some have actually used them.
I don't think anyone would say that the hone would not work especially on a troubled razor. This is where it will shine and help those that are unable to be successful on a flat hone to the same degree.
The biggest reason for being unsuccessful on a flat hone is geometry or a non flat hone (warped etc.) the convex cures that.

It is the benefits vs a flat hone. Pros and cons that have been offered throughout the thread.
The pros do not outweigh the cons for many of us.
They will work, some will love them and think the world of them - just like any other hone.
A properly lapped flat hone will be more consistent and maintain more of the razors original properties for longer.
Learning how to hone on a flat hone while keeping proper geometry on a razor is a benefit not a hinderance.

I'm not arguing with many of these points.

I know how to hone on flat stones but my edges are better off the DCA. No doubt about it. I am, however, thinking about honing a razor or two entirely on flat stones just for fun. Maybe ending with the Zulu Grey (which I know will deliver, at least mine will).

Happy shaves,

Jim

 

[stone and strop]

I know how to hone on flat stones but my edges are better off the DCA. No doubt about it.

Why are they better?
Given you have two identical hones and one is convex, if you hone well on a flat hone then shouldn't the end results be similar?
Other than reaching all parts of the edge quicker through convexing it is the same thing unless there are minor geometric issues at hand which lends itself to the latter.

 

[FXDX]

Why are they better?
Given you have two identical hones and one is convex, if you hone well on a flat hone then shouldn't the end results be similar?
Other than reaching all parts of the edge quicker through convexing it is the same thing unless there are minor geometric issues at hand which lends itself to the latter.

Speculating, but the pounds per square inch is dramatically higher. By example the force of a record player stylus in the vinyl record groove is upwards of 6000 pounds per square inch because of the millionth of a square inch of contact. If your razor is flat on the stone vs a portion of the edge on a convex stone, the contact pressure is vastly different. And I suspect there is a tendency for the pressure to equalize across the edge on a convex stone vs a flat stone due to irregularities of the razor geometry. Again, speculation. Anyway if it works for someone, keep doing it. I'll bet things that work for me won't work for others.

 

[stone and strop]

Speculating, but the pounds per square inch is dramatically higher. By example the force of a record player stylus in the vinyl record groove is upwards of 6000 pounds per square inch because of the millionth of a square inch of contact. If your razor is flat on the stone vs a portion of the edge on a convex stone, the contact pressure is vastly different. And I suspect there is a tendency for the pressure to equalize across the edge on a convex stone vs a flat stone due to irregularities of the razor geometry. Again, speculation. Anyway if it works for someone, keep doing it. I'll bet things that work for me won't work for others.

This would only speed things up a bit as mentioned above.
Still, in use, hundreds of strokes are not uncommon.
A few more on a flat hone should eventually bring the same edge. Why wouldn't it?

 

[lightfoot]

So......
I tried to dress down one of my Soft Arkansas stones to 220 on one side & 600 on the other. I did this on a piece of plate glass. My intent was to flatten the stone but what I wound up with was a beautifully convex surface on both sides along the width & length by accident! Honestly I’m quite happy now. A double convex stone without even trying to get there...

 

[Biglo13]

Curious if you checked stones with straight edge prior to lapping? I found most of the stones I have checked sold as flat actually had hump at or near center of stone.

 

[lightfoot]

Curious if you checked stones with straight edge prior to lapping? I found most of the stones I have checked sold as flat actually had hump at or near center of stone.

I did check it. It was actually dished in the middle. I also checked the stone periodically during lapping. I thought I was never going to get the glazed surface in the middle out of the stone. When I was done to my surprise while checking it with a straight edge it was perfectly convexed. I can spin the stone on a flat surface and it spins perfectly. So I verified it with a straight edge and by spinning the stone on a flat surface.

 

[Chan Eil Whiskers]

A properly lapped flat hone will be more consistent and maintain more of the razors original properties for longer.

What razors are you talking about here?

According to my understanding hollow ground razors from Solingen and Thiers factories were honed originally on convex stones.

To maintain their original properties one would have to use a convex stone.

Using a flat stone would alter their original properties.

Perhaps you're talking about other razors.

Happy shaves,

Jim

 

[alx gilmore]

My impression was that
"According to my understanding hollow ground razors from Solingen and Thiers factories were honed originally on convex stones. "
they were just touched up before leaving the factory on the convex stones seen in the video. I could be wrong.

Alex

 

[stone and strop]

What razors are you talking about here?

According to my understanding hollow ground razors from Solingen and Thiers factories were honed originally on convex stones.

To maintain their original properties one would have to use a convex stone.

Using a flat stone would alter their original properties.

Perhaps you're talking about other razors.

Happy shaves,

Jim

Doing the math at the smaller radius and using a 6/8 razor there would be a reduction in the inclusive bevel angle of .1º and the dish in a .5mm bevel reveal would be less than 1 micron. Far less effect at the larger radius.

I am of course referring to the relation of spine to edge and maintaining the straightness of both.
The undercutting of the bevel is inconsequential.
Lets remember the most obvious of reasons for MFG's to use them in the first place regardless of what some say.
The MFG can move more product quicker out the door especially with a slightly warped razor.
This simply CANNOT be overlooked as a viable reason for implementing the convex hone.
I realize the factories suggested you return your razor to them for re-honing but lets be realistic here. Barbers honed their own razors. Homeowners honed their own razors. NONE of them used a convex hone.

They were a great idea for MFG's - no doubt. Whoever came up with the idea had a money maker for sure.
It is practical.

What continues to be ignored is the fact that some razors leave the factory that clearly have issues.
I do not begrudge them for using one for the reasons given but the razor should be able to be maintained with standard tools. Really, who is going to send their razor across the world for a re-honing?
I have honed several NEW Solingen razors that were warped but had a pretty consistent bevel and no abnormal wear on the spine. This clearly shouts convex/narrow hone.
The hazards with regard to maintaining geometry is the razor can still be honed but if it has a frown it will not shave well even if honed well and the problem will be irreversible at some point.
Flat is easier to maintain both.

You never answered the question above.
If you can hone on a flat hone as well as on a convex hone then why are the edges better off the convex?
All things being equal stone wise. Why would the end result differ?
Most others that use Arks are using them flat with outstanding results.

 

[stone and strop]

Seems like this thread has been interesting lately and I’ve kinda missed out.


I bought one of these convex arks a while back. It’s a decent stone nothing spectacular. I lapped the bottom of the stone flat and ended up using that side more often to be honest. I started getting much better results from my jnat though and completely stopped using the ark.

How long did you use the convex prior to abandoning?
Why was the flat more desirable for you. Just curious.
I think you are the only one of the few that purchased one that has stopped using it.

 

[Basil]

How long did you use the convex prior to abandoning?
Why was the flat more desirable for you. Just curious.
I think you are the only one of the few that purchased one that has stopped using it.

I used the stone for a few months. Used it to hone all of my razors at one point. The flat side of the ark was faster to get a better edge It took more laps for me on the convex side.

 

[stone and strop]

I used the stone for a few months. Used it to hone all of my razors at one point. The flat side of the ark was faster to get a better edge It took more laps for me on the convex side.

Surprising, Thank you.

 

[FXDX]

I used the stone for a few months. Used it to hone all of my razors at one point. The flat side of the ark was faster to get a better edge It took more laps for me on the convex side.

And another honer with different pressure and angle of attack might have a different result. I am convinced stones and honers must find each other.

 

[Chan Eil Whiskers]

In response to questions I asked of him, and in an effort to overcome my difficulties understanding the English language, Jarrod sent me this video and told me I could share it.

It's very interesting stuff, and not just for convex stone devotees. Check it out...

I have the small convex on one side, concave on the other stones which Jarrod sells. There are two. One is about $12. The other, about $22. Either will work for this. Or, you can make your own.

Here's another interesting video. I've not studied it and am not vouching for it, but it looks interesting.

My plan is to apply some of what the top video teaches, but I need to study the matter just a bit more first.

I hope this is of use to some of you.

Happy shaves,

Jim

 

[Steve56]

Don’t buy a razor hone from J Peterman....

 

[David]

Don’t buy a razor hone from J Peterman....

Why’s that, Steve?

 

[FXDX]

I wouldn't buy one from Old Navy or Bed Bath & Beyond either.

 

[Biglo13]

Jim,
Have found the need to use concave conditioning stone? Unsure if hobbyist hiner would ever need it especially on harder arks.