.3mm over what distance?
Convex club.
- Thread starter kohalajohn
- Start date
That's going to be pretty flat. Since I would assume that your hone is much smaller than your tile, if you concentrate your early work in the center of the tile you will be working to increase the sagitta of the tile while starting to convex the hone.
.3 mm saggita over a 12" span= 127' radius
Thinking about this a bit more, even trying to work the tile evenly will increase the dish as there is less surface area in the center of the tile than the outsides. Just keep rotating, or walking around, the tile as you lap.
I'm very interested in your project.
Chan Eil Whiskers
Fumbling about.
Probably someone here knows exactly how that compares with Jarrod's.
Interesting...
Happy shaves,
Jim
chan- Jarrods masters are based on .5mm saggita over 12 inch tile.
I saw your post about longer strokes rubbing 2 tiles / lens with grit will increase depth. May try that. It is slow work hogging out. A piece of granite.
I did most of the work on a potter wheel
There will also be some variance when convexing hone.....
I've never seen definitive measurements for Jarrod's tile, but based on a .5 mm crown on an 8" hone it works out to be a 33.8' radius.
This just in; with a .5 mm saggita over 12 " = 76.2' radius
I never saw him actually measure it. But I’m going on what he told me. .5 mm saggita for 12 inch tile.
Wow .2mm. Makes a huge difference. (Im not so good with the actual math)
Radius sounds about right. He did mention that somewhere
There will be some variance related to lapping/hogging out technique.
Careful with that info. That was for a mirror and tool of the same size with the mirror on top.
Chan Eil Whiskers
Fumbling about.
Not my post. I don't know anything about doing that stuff. I barely fumble about well enough to hone.
Happy shaves,
Jim
Wont the directions follow same size tile. Square tile vs round lens. I remember similar directions on telescope lens making info. You just described differently. My tool tile ended up getting deeper faster than original lens piece ..... ( prolly just confused everyone )
I found this site to contain a lot of hands on info; Telescope Making - Wikibooks, open books for an open world - https://en.wikibooks.org/wiki/Telescope_Making
I used my 6x2" combo convex ark to touch up the factory edge on my Boker Inox XFH 5/8 the other day. I used very light pressure on the trans side only with a swaying and slightly rolling x-stroke. The results were greatly improved from the last razor I honed on this ark, and a definite improvement on the factory edge. I think I was using too much pressure before.
My experience has been that what @SliceOfLife has called the "hoverhand" method of super-light pressure is not ideal when finishing on a flat trans ark, which is why it wasn't the first approach that I took with the convex trans ark. I guess the convexity is concentrating the force to the point that conventional methods are once again ideal.
Having done both now, I definitely prefer the experience of finishing with a water medium using very light pressure on the convex trans ark to finishing with a thicker medium of lather or diluted glycerin using moderate pressure on a flat trans ark. You actually get a bit of feedback (nothing like a coti or jnat, obviously, but not totally dead like a flat trans ark), and it's quicker and less messy. From a performance perspective, the final edge seems pretty similar.
I think I'm going to experiment with some Gold Dollars and ZYs that I've had sitting around for a while to determine what the quickest/best way to get them shaving well is, out of the options I have available. The candidate progressions are:
Having done both now, I definitely prefer the experience of finishing with a water medium using very light pressure on the convex trans ark to finishing with a thicker medium of lather or diluted glycerin using moderate pressure on a flat trans ark. You actually get a bit of feedback (nothing like a coti or jnat, obviously, but not totally dead like a flat trans ark), and it's quicker and less messy. From a performance perspective, the final edge seems pretty similar.
I think I'm going to experiment with some Gold Dollars and ZYs that I've had sitting around for a while to determine what the quickest/best way to get them shaving well is, out of the options I have available. The candidate progressions are:
- convex soft ark -> convex trans ark
- D8F -> tomo slurry on fast fine jnat -> water on fast fine jnat (I have a fair amount of experience using this progression on nicer razors and in that context it works quite well, but I haven't explored its suitability with razors that have stupid 21 degree bevel angles and "who knows what alloy and HT?" steel)
- D8F -> fast coti with slurry (or maybe diamond slurry on a fast jnat?) -> CBN on a cloth strop
Chan Eil Whiskers
Fumbling about.
I find the soft convexed side of my Double Convex Arkansas 8x3 stone very very useful. However, I don't attempt what I think of as an actual bevel set with it.
- If I were starting with a razor I knew had been previously honed entirely on flat stones, a razor which had been sharp and shave ready, a razor I knew still had a very good bevel but just needed tuning up, I would begin with the soft side of my DCA.
- If I were starting with a razor which came to me in excellent shape and shave ready, but I wasn't sure how it had been honed, and I wanted to put a DCA edge on it, I would begin with the soft side of the DCA.
- If I were starting with an edge previously honed to a shave ready state on a convexed stone (either a convex coticule or a convex Ark), I'd begin either on the soft side of the DCA or on the hard, finishing, black side of the DCA unless the bevel had been damaged.
- In any of these situations I might substitute the convex coticule for the soft side of the DCA as a first step, or I might add the convex coticule after the soft side of the DCA.
- Bottom line for me is I only begin with the soft side of the DCA when I know the bevel is good.
I use the soft side of the DCA to convert a good flat bevel to bevel made by a convex stone!
I'm not entirely sure if Jarrod at Superior Shaves uses the soft side of his DCA as a bevel setter in a way different from me. I kinda think maybe he does, but, then again, he may be starting with better bevels than I'm sometimes starting with. It's also certainly true that he has vastly more experience than me with the stones, and particularly with the convex Ark. He may have the secret sauce to take an eBay not sharp unknown condition edge from zero to a very good bevel using only the soft side of the DCA but I don't.
My adventures with the razor I used today could serve as a good case in point.
Happy shaves,
Jim
you have confirmation of technique from another convex user. i have been doing the same, set bevel first, in my case 1k king or lapping film then to soft/coarse convex ark. pretty much same as above minus convex coti.
DMT D8F. A continuous diamond hone with a 25 micron nominal particle size. Mine is well broken-in and actually leaves a very nice bevel that you can shave off of directly, although anyone not doing a stunt would of course use something finer afterwards.
