So in your world Dovo haven't mastered their craft?
Convexed Dovo Hone
- Thread starter lightfoot
- Start date
So in your world Dovo haven't mastered their craft?
Aren't convex stones the traditional tool to sharpen a full wedge straight razor?
Full wedges were actually periodically reground by tinkers, barbers and manufacturers back when they were commonly used.
No stones, then. Interesting.
Oooh. This old thread is awake again. I think the interest in convex stones is increasing.
My understanding is that convex stones were used to hone hollow ground razors, not just wedges.
Since the bevel rests on an arc, the bevel itself becomes slightly concave. This is good because the shoulders are out of the way, allowing the edge to touch the stone and be sharpened. Also it makes the angle more acute.
Convexity also means every point of the edge touches the stone at some point, even if there is a slight warp or smile.
Convexity also means the honing proceeds faster. Because only a portion of the blade is in contact, that portion receives all the pressure. So the job gets done in less time. While we don't care about speeding up the process, we do benefit from speed as it means we don't need a progression of several stones. With flat stones, nobody wants to go from bevel setting to 12k in one jump as it would take a long time. But with the speed of a convex stone you can. You can set the bevel on a convex soft ark and then go straight to a convex black ark. The convex black ark does the job of a 3k, 5k, 8k and 12k. At least that's Jarrod's experience and he's doing it a lot.
I always wondered why the german razor makers like Aust and the rest, were saying that we were using a needlessly high number of stones. I think the above reason is why. They were using convex stones. And only a bevel setter and a finisher.
I have not yet tried a convex ark, but I thinking about buying one to see.
My understanding is that convex stones were used to hone hollow ground razors, not just wedges.
Since the bevel rests on an arc, the bevel itself becomes slightly concave. This is good because the shoulders are out of the way, allowing the edge to touch the stone and be sharpened. Also it makes the angle more acute.
Convexity also means every point of the edge touches the stone at some point, even if there is a slight warp or smile.
Convexity also means the honing proceeds faster. Because only a portion of the blade is in contact, that portion receives all the pressure. So the job gets done in less time. While we don't care about speeding up the process, we do benefit from speed as it means we don't need a progression of several stones. With flat stones, nobody wants to go from bevel setting to 12k in one jump as it would take a long time. But with the speed of a convex stone you can. You can set the bevel on a convex soft ark and then go straight to a convex black ark. The convex black ark does the job of a 3k, 5k, 8k and 12k. At least that's Jarrod's experience and he's doing it a lot.
I always wondered why the german razor makers like Aust and the rest, were saying that we were using a needlessly high number of stones. I think the above reason is why. They were using convex stones. And only a bevel setter and a finisher.
I have not yet tried a convex ark, but I thinking about buying one to see.
This is the video I found last year for using a convex/dished stone with a wedge type.
That is concave rather than convex. I guess you could hone outwards at the ends of a convex stone to achieve the same result.
Interesting... I might try that...
Oh my, my bad.
A convex hone would be mostly useless on a wedge. You'd want a concave hone. A hone that's high in the middle would be extremely unstable and not repeatable at all on a flat ground wedge.
I don't think that using a convex hone means that the razor manufacturers who use one aren't masters of their craft at all. They just want to make things quicker and easier for every razor so they can spend less time fiddling in case there's one that isn't geometrically perfect. Anyone who doesn't think this is the case either has never worked in a manufacturing environment or is crazy IMO. There has never been a manufacturer that didn't care about how much time was spent on manufacturing their product. This directly affects profit.
I don't think that using a convex hone means that the razor manufacturers who use one aren't masters of their craft at all. They just want to make things quicker and easier for every razor so they can spend less time fiddling in case there's one that isn't geometrically perfect. Anyone who doesn't think this is the case either has never worked in a manufacturing environment or is crazy IMO. There has never been a manufacturer that didn't care about how much time was spent on manufacturing their product. This directly affects profit.
I just ordered a black translucent convex Ark hone 7 7/8"X 3" from Jarrod. I have been thinking about using a convex stone after seeing videos from Murray Carter and a number of Japanese knife sharpeners. They all say a convex or concave stone is better to hone on. It depends on whether you are honing a knife or razor I would think. I should have the stone tomorrow and will take it out for a test, but not on one of my custom razors. As a former engineer, I really look forward to seeing how this works. I got the larger stone to take one variable out of the procedure. The blade should sit perfectly on the 3" wide stone.
If it is a convex hone, the stone width is immaterial. The blade is only going to contact a small fraction of the stone at a time. At least that how I thought the convex hones were shaped.
I just received my translucent ark black 3 x 8 convex stone from Jarrod. First, I took my industrial steel ruler and placed the edge length wise on the stone. There is a subtle arch midway on the stone. I then sprayed a 50-50 mix of water and ballistol on the stone. I took a Koraat full bellied 7/8 razor I shaved with yesterday and did 50 X stroke laps. I then did 50 back and forth strokes. The razor remained flat on the stone when honing. I went and shaved with the razor and my observation is that the shave was smoother. The blade remained extremely sharp. I really didn't notice any difference in honing on a convex or flat stone as far as the position of the razor and stone. I want to play with this some more and compare the edge with my Zulu Grey. Will post a picture tomorrow and update when compared to a flat Zulu.
Very good point!
I'm very glad you bought that, A Cut Above. I have been talking with Jarrod about this and am very close to buying a convex combo as well.
Jarrod said he uses five parts water to one part Ballistol
Jarrod said he uses five parts water to one part Ballistol
Just bought my convex combo Ark from Jarrod. Very excited.
The light hued side is the soft one, for bevel setting. The black side is a black translucent, for finishing.
Will rest the stone on the table for bevel setting. For finishing or maintaining, I plan to hold in the air, freehand.
Water/Ballistol. I keep a Ballistol soaked cloth in the bathroom anyway, to wipe down the blade before putting away.
I am interested in finding out the frequency needed, to maintain. I expect at first I'll probably do it more than needed, just out of curiosity/fun.
The light hued side is the soft one, for bevel setting. The black side is a black translucent, for finishing.
Will rest the stone on the table for bevel setting. For finishing or maintaining, I plan to hold in the air, freehand.
Water/Ballistol. I keep a Ballistol soaked cloth in the bathroom anyway, to wipe down the blade before putting away.
I am interested in finding out the frequency needed, to maintain. I expect at first I'll probably do it more than needed, just out of curiosity/fun.
I'll have to try adding more water to my mix.
So much fun, yes?
Oh wow, I'm glad I bought that 8x3 convex when I did.
Jarrod has discovered that the big rocks are way too much labour to convex. He's going down to 6x2.
Have a look at the video of him fighting to convex the big rock. it's hilarious.
I thought he was just sending them out to some machine based third party system. Nope. He's doing it all by hand. He puts a sheet of coarse grit sandpaper on his concave granite plank and just goes at 'er.
Twenty minutes of hard labour to convex a 6x2. Eighty minutes to convex a 8x3
Jarrod has discovered that the big rocks are way too much labour to convex. He's going down to 6x2.
Have a look at the video of him fighting to convex the big rock. it's hilarious.
I thought he was just sending them out to some machine based third party system. Nope. He's doing it all by hand. He puts a sheet of coarse grit sandpaper on his concave granite plank and just goes at 'er.
Twenty minutes of hard labour to convex a 6x2. Eighty minutes to convex a 8x3
i saw the video a couple days ago. i couldnt figure out how he was convexing other than applied unequal pressure. so there is a concave plate? interesting.
Yeah, the dude spent like 25 hours with loose coarse grit, grinding out a concave hollow in the middle of a huge granite plate. Crazysauce.
