I convexed a Shapton 1K myself which is what I use as a bevel setter before other convex stones. Works well and is extremely quick.
Convex club.
- Thread starter kohalajohn
- Start date
A secret technique of my own... ah, what the hell...
Some background: I bought a convex coticule bout from Jarrod and had been using that for a while, but I couldn't quite get happy with it. It was very hard to maintain the contact I wanted right to the heal. I had a flat 2" 8 6" rectangular coticule that was very soft and slow and never honed very well, so thought I would convex that myself.
At first I thought a bit about making a concave master, but as this was a stone that I wasn't too worried about eventually I decided to freehand it. I took my flat veritas lapping glass plate with silicon carbide wet n dry on top. I started by lapping flat and then I gradually lifted an edge. Just by feel I continued lifting as I lapped and graduated this as I went. It was all by feel - like when you vary the torque as you hone - same here. I did this all the way round the stone, checking with a straight edge to eyeball the curvature as I went. Eventually I ended up with a consistent cushion shape. To correct this I rolled the lapping motion at the corners to smooth these surfaces out into a consistent oval.
That was the first coticule. I much preferred it to the bout from Jarrod. For my personal technique, the degree of curvature works much better.
I have convexed three other coticule in the same way since, with a small but useful change to my technique, and it was this new approach that I used with the Shapton.
1. Lap the stone flat. - important to avoid concave spots.
2. draw a fine grid on the stone.
3. Lap with a very slight lift on one edge.
4. Inspect the grid on the other edge. Only part should have been removed.
5. check with the straight edge
6. Redraw grid
... keep repeating
the aim is to progressively lap wider and wider strips of grid off the stone until you reach an apex. The grid allows you to see how much you are taking off, although the real judgement is made by checking with the straight edge.
that's my technique. All you precise engineers can burn me now, but I have used it on 5 stones in total, and I am happy with it. I am getting great results on Gold Dollars and cheaper Dovos. It solves a lot of problems when honing wonky geometry Dovos. I find I can reset the bevel without having to hone a lot off the razor or without a complicated rolling stroke.
I would not attempt it with an ark, I don't think. It is pretty easy with softer stones.
Some background: I bought a convex coticule bout from Jarrod and had been using that for a while, but I couldn't quite get happy with it. It was very hard to maintain the contact I wanted right to the heal. I had a flat 2" 8 6" rectangular coticule that was very soft and slow and never honed very well, so thought I would convex that myself.
At first I thought a bit about making a concave master, but as this was a stone that I wasn't too worried about eventually I decided to freehand it. I took my flat veritas lapping glass plate with silicon carbide wet n dry on top. I started by lapping flat and then I gradually lifted an edge. Just by feel I continued lifting as I lapped and graduated this as I went. It was all by feel - like when you vary the torque as you hone - same here. I did this all the way round the stone, checking with a straight edge to eyeball the curvature as I went. Eventually I ended up with a consistent cushion shape. To correct this I rolled the lapping motion at the corners to smooth these surfaces out into a consistent oval.
That was the first coticule. I much preferred it to the bout from Jarrod. For my personal technique, the degree of curvature works much better.
I have convexed three other coticule in the same way since, with a small but useful change to my technique, and it was this new approach that I used with the Shapton.
1. Lap the stone flat. - important to avoid concave spots.
2. draw a fine grid on the stone.
3. Lap with a very slight lift on one edge.
4. Inspect the grid on the other edge. Only part should have been removed.
5. check with the straight edge
6. Redraw grid
... keep repeating
the aim is to progressively lap wider and wider strips of grid off the stone until you reach an apex. The grid allows you to see how much you are taking off, although the real judgement is made by checking with the straight edge.
that's my technique. All you precise engineers can burn me now, but I have used it on 5 stones in total, and I am happy with it. I am getting great results on Gold Dollars and cheaper Dovos. It solves a lot of problems when honing wonky geometry Dovos. I find I can reset the bevel without having to hone a lot off the razor or without a complicated rolling stroke.
I would not attempt it with an ark, I don't think. It is pretty easy with softer stones.
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Chan Eil Whiskers
Fumbling about.
Amazing!
I'm not sure I understand exactly what you're doing, but, then again, I'm not fixing to attempt this and I'm sure diving into it with your instructions and hints would be vastly better than diving into it from scratch.
You're an adventurer!
Just to make sure I got this: You're using your convex coticule to set the bevel on Gold Dollars and other razors which have had (by you) no work on any previous bevel setter? Amazing. I love it.
Happy shaves,
Jim
I am using a Shapton 1K which I have convexed myself using the technique that I described above and then I follow this with a dilucot progression on a convex coticule.
I'd love to follow this with a convex ark but Jarrod sold out before I could order one. I think I would only get a hard 2 inch wide one which would follow nicely from the coticule.
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Chan Eil Whiskers
Fumbling about.
Oh, sorry for missing that detail. I know I read it, but it didn't stick. Now I've got it. Very cool idea to convex the synthetic (The World's Only ___).
So, if I'm getting this right, you'd take any razor (regardless of its history) and begin with that convex synthetic 1K? No previous bevel setting on any other stone? I'm pretty sure that's what you're saying, and I like it very much.
Jarrod is indeed sold out of the convexed Arks (other than "rubbing stones"). From what he's written I believe - and I could be wrong about this - more are coming, but they will be in a size even smaller than the last offerings.
All that makes my Double Convex Arkansas 8x3 a very unusual stone. I acquired it with considerable trepidation as it was quite expensive by my standards. It was by far the most expensive stone purchased by me or even considered for purchase by me, but it turns out to have been a bargain. All that real estate...
That said, I was aware that the smaller DCA stones would work very well. I mean the ones now unavailable and perhaps never to be made again by Jarrod. It's impossible for me to imagine he won't offer a still smaller sized convexed Ark; he's been way into the stone as THE stone, promoting it, arguing for its use, etc. However, that's not the same as agreeing to do the labor.
My friend, a mechanical engineer, who is the kind of guy who can flat out fix anything remotely related to construction, engineering, etc. was an interesting guy to discuss the convex stones with.
I told him about using convex Arks to hone my razors. He knew about Arks already and "got" the convex stone advantage before it was half out of my mouth. My question to him was how he'd suggest making Arkansas stones convex. He immediately told me the way to go would be to use a milling machine.
Of course this would be a solution with any stone. Business idea: Buy a milling machine. Set it up to convex stones. Convex for sale all the stones. Convex for hire anybody's flat stone. Hey, it might work as a business. It would definitely work according to my buddy as a way to make convex stones without hours of hard labor. The stones would be precise.
Happy shaves,
Jim
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Jarrod advised me that you can progress from flat to convex but not the other way round. As I love my flat stones more I am only using my convex stones for Dovos and Gold Dollars.
Why?
I find that the convex stones get around dodgy geometry easily, in particular with low end Dovos, according to Jarrod they are honed at the factory on convex hones. There is much less work to hone them that with a flat stone and I avoid the necessity of major correction or of honing gymnastics to keep a neat bevel. In my head it's the same as honing a serated knife with a round hone, just that the roundness is more gradual.
Why?
I find that the convex stones get around dodgy geometry easily, in particular with low end Dovos, according to Jarrod they are honed at the factory on convex hones. There is much less work to hone them that with a flat stone and I avoid the necessity of major correction or of honing gymnastics to keep a neat bevel. In my head it's the same as honing a serated knife with a round hone, just that the roundness is more gradual.
Chan Eil Whiskers
Fumbling about.
It would be interesting to know for sure which factory honed razors were honed on convex stones. I know it's not just Dovo razors, but that's not to say all European (or even all Solingen) razors were factory honed on convex stones.
It would be interesting to me to hone to the sharpest degree possible one of my razors on just flat stones. Perhaps the flat coticule as a mid range and the Zulu Grey or a flat Ark as a finisher. Then, if I wanted to I could easily enough go to the DCA more more sharpness.
Problem there is keeping up with which razors were subjected to what. Easier to just finish everything on convex Ark stones.
Happy shaves,
Jim
I don't get that part at all. I would not expect to have trouble going either way, but convex to flat should be particularly easy unless the blade is wonky.
You are probably right. I might hone back and forth between convex and flat with a couple of GDs at some point and track contact with a sharpie to try to work out what is happening.
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convexed stones?! bunch of bullarchy!
Chan Eil Whiskers
Fumbling about.
Playing with my convex coticule and convex Ark stones today. My latest victim is the Red Tanifuji.
We'll see. I'm not terribly confident, but that has been an unreliable indicator.
Happy shaves,
Jim
We'll see. I'm not terribly confident, but that has been an unreliable indicator.
Happy shaves,
Jim
Chan Eil Whiskers
Fumbling about.
This new to me razor was purchased at johnloc's eBay store. It's a nice razor but not according to my standards as sharp as I want a razor to be. My understanding is johnloc hones with tape.
How should I go about honing on the DCA? I'm not going to use tape! So, I'm asking how to hone a razor without tape (knowing it was previously honed with tape) on a convex stone.
The razor is an ERN but it looks a bit like a Torrey 136.
I know I could totally reset the bevel (with the Chosera 1K, etc.) but do I have to do that? I believe but don't know 100% the bevel is good (as a taped bevel).
This thread answers many involved questions, but not concerning the convex stones.
I have great inability to visualize (even making drawings which I did) the issues involved here.
Yes, I could just dive in and see how it goes but I'm trying to understand and learn something here.
Thanks...
Happy shaves,
Jim
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Nice piece, chan! The answer to your question can only be answered by you. If you want to preserve the polish on the spine, continue to tape. If spine scratches don't bother you, then just get on with it and get a serviceable edge that you want to maintain how you want to maintain it and go on.
Chan Eil Whiskers
Fumbling about.
Oh, there's zero chance of me using tape. That's not of issue at all.
sharpie bevel take a few passes on convex coti until you remove sharpie. maybe convex coti with slurry. re mark bevel take more passes again. here i like using loupe or scope. to confirm... this will speed the conversion to convex edge........ i would consider it more conversion to "a convex bevel" more than traditional bevel reset
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Do you have a coti slurry stone, or other coti to raise slurry on or with. Curious if concave rubbing stone would raise slurry on convex coti? While coti can be a great finisher with out slurry. a coti with slurry serves multiple lower grit ranges. If I owned a convex coti. I would have a separate coti bout/ringtone and create a diamond slurry from that vs creating slurry from the convex coti In order to preserve the convexity longer.
Chan Eil Whiskers
Fumbling about.
Great idea.
I have three coticules & a coticule slurry stone.
- The convex coticule.
- A longer rectangular coticule. Flat.
- A bout. Flat.
?
I also have the Double Convex Arkansas 8x3. I was thinking of perhaps using the soft side of the DCA before the coticule. Obviously, there are various ways to approach this conversion to a convex bevel project.
From using the flat rectangular coticule with a slurry and gradually diluting the slurry I'm familiar with it's capacities. It will go from bevel setter to finisher. I'm not totally wild about the sharpness it produces although it will make an edge which is more shave ready than it feels like it should be.
However, I want to preserve the convex coticule for its finishing stone capacity (meaning not wear it down too much too soon). Thus, I'm considering using the soft side of the DCA as the initial tool to accomplish the conversion of the bevel to a convex bevel project. Then the convex coti? Then the hard side of the DCA?
Any thoughts about this?
I'm very unfamiliar with using the sharpie and marking the bevel and following things that way. I get it in principle but that's not the same as experience.
Happy shaves,
Jim
Chan Eil Whiskers
Fumbling about.
I know the soft side of the DCA is called a bevel setter by Jarrod, and I know he uses it to set the bevel.
I would think the convex coticule a "finer" stone than the soft side of the DCA, meaning if used without slurry I'd think it would go after the soft side of the DCA and before the hard side of the DCA in a progression.
Jarrod said to consider using the convex coticule after the hard side of the DCA.
I know I can get a pretty sharp edge with the convex coticule. I believe not as sharp though as the Ark (DCA, hard side) edge. I've not shave tested the convex coticule edge so I'm going by finger pad tests and such.
I also know I can get sometimes a surprisingly sharp edge off the soft side of the DCA. Again, not shave testing it of course. Not as sharp as the hard side of the DCA, but surprisingly sharp. It's easier to get this sharp edge off the soft DCA than to get a similar sharpness off the convex coticule. But, I think I can get more sharpness with the convex coticule (more sharpness than I can get off the soft DCA); it just takes a while and very light strokes.
Generally my objective with the DCA soft side is more bevel setting than a sharp edge so I'm just reporting my observations.
Again, I don't know anything and am just fumbling about with stones and experimenting and learning a bit here and there.
Happy shaves,
Jim
I would think the convex coticule a "finer" stone than the soft side of the DCA, meaning if used without slurry I'd think it would go after the soft side of the DCA and before the hard side of the DCA in a progression.
Jarrod said to consider using the convex coticule after the hard side of the DCA.
I know I can get a pretty sharp edge with the convex coticule. I believe not as sharp though as the Ark (DCA, hard side) edge. I've not shave tested the convex coticule edge so I'm going by finger pad tests and such.
I also know I can get sometimes a surprisingly sharp edge off the soft side of the DCA. Again, not shave testing it of course. Not as sharp as the hard side of the DCA, but surprisingly sharp. It's easier to get this sharp edge off the soft DCA than to get a similar sharpness off the convex coticule. But, I think I can get more sharpness with the convex coticule (more sharpness than I can get off the soft DCA); it just takes a while and very light strokes.
Generally my objective with the DCA soft side is more bevel setting than a sharp edge so I'm just reporting my observations.
Again, I don't know anything and am just fumbling about with stones and experimenting and learning a bit here and there.
Happy shaves,
Jim
