Might be fun to just spray a few grits on a strop and see what the witch's brew does :)
Might be fun to just spray a few grits on a strop and see what the witch's brew does :)
I can visibly see the difference in edge quality between a 1um edge and a 0.5um edge, with the 1um looking slightly "rougher". Even so, the 1um feels much nicer on my face.But the features we are talking about are not going to be seen with light microscopy. Maybe the larger scaled features of the edge, but not the radius of the bevel junction or those smaller features you can see on the SEM photographs from Verhoveven's paper.
One, two! One, two! and through and through...The vorpal blade went snicker-snack!
My Vorpal Razors
I don't have anything but the 0.125 CBN so I can't try it. I think Seraphim's observations are interesting. i'm puzzling why finishing on the CBN then putting ever so slight a secondary bevel with the coticule gives me a demonstrably sharper edge than coticule alone, but re establishes the smoothness. What is it about the coticule edge that makes a distinct difference that is not at a scale that would take away the keenness of the smaller edge radius? It may well be that it just gives an edge somewhere between the coticle's effective grit equivalent but not as fine as 0.125 and so is akin to 1 um alone.
Ken, I'd love to see those micrographs if you run across a link somewhere. Are they truly a time series of the same slurry at different stages of breakdown showing a shift in the size frequency distribution or just a piccie of the slurry showing a range of particles?
I'd love to see a good SEM of a coticule slurry over time as well, but these things are hard to do preps on. I also think that the swarf that enters the slurry and oxidizes and mixes with it changes its texture and chemical properties in ways we don't understand.
Lots going one and I am still convinced that at the scale of the sub micron particles it isn't all about scratch patterns and their depth. I think other forces are coming into play at those scales. Just a hunch.
Yea I tried to find it. It isn't a time series but just a static SEM micrograph showing a range of particles. I'll have to see if I can do something with my camera to demonstrate this. Could be fun. And challenging. My macro gear might just be able to go to a level to demonstrate this. My feelings are that the metal swarf has a bit of a burnishing effect as a slurry component, but it's more intuitive than something I can back up with hard data at this point. Lots of exploration and learning to go ...
So I got a week's worth of great shaves out of the Argus I treated as described previously. It was still popping hairs at HHT >3. This is a good sign for me as I usually blunt an edge in a week's worth of shaves. I did notice that a microchip had developed in the mid blade area, so I went back to a dilicot with my Verte, then fabric and leather to HHT4. This time I did 60 laps on the hanging leather w CBN before putting one more layer of tape and doing 25 light laps on my Verte. As usual it finished with a 4+ HHT after fabric and leather. I'm doing this wrong, of course, by changing two variables at once by playing with the CBN hanging strop and secondary bevels at the same time. But I'm having fun with it and I can only shave so many times to test results.
While I had the Verte out I took my silversteel Joseph Elliot back to the bevel and did a dilicot to about HHT 3.5 using one layer of tape. Then for laughs I did 30 laps on the CBN. This was a blade that felt really harsh shaving off the CBN. I then put two additional layers of tape for a final bevel angle of 19 degrees and did 25 very light laps on the Verte, finishing with 100 canvas and 100 brushed shell. Shaved with that one this morning.
Wow. OK, I'm used to a blade pulling just a bit on some parts of my initial pass. Does this on my edges and all the edges anyone else has ever put on a blade. Tough whiskers and it isn't the end of the world. I'm used to a little razor burn after I do enough passes to get BBS, no biggie. But this edge this morning did not pull anywhere anytime. Went ATG on my upper lip, which is now smooth as can be and I had no trace of razor burn when I was finished.
The purist in me recoils at taping and using pastes but the pragmatist says "shut up and try this" and it is winning out so far. In the coming weeks I will continue to try to parse out the effect of the CBN from the effect of the secondary bevels. But for now I'm just having fun and enjoying great shaves. It still puzzles me how a few laps on the coticule restores the smooth forgiveness of the coticule edge but retains that extra bit of keeness from the CBN. Practice is clearly outstripping theory in this pursuit, but whatever, i'll just keep on playing, that's half the fun of this hobby.
i will be watching this thread! thanks men. tom
I can honestly say threads like this are a total revelation to me! Until reading things like this, I could not imagine anyone besides manufacturers or researchers taking this level of interest in such technical detail about a razor! This board is a continuing eye opener!
Great reading! Let the experimentation continue....
Let's not forget that with a coticule or other stone with slurry we hone the razor edge forward and the particles not only touch the bevel, thereby sharpening it but also come in contact with the very edge of it thereby dulling that edge.
On a pasted strop (leather, balsa, felt) we strop it edge trailing, not bumping the particles into the edge.
Also the direction sharpening the razor (edge forward or trailing) can make a great difference, even without slurry.
To compare a coticule (or other) with or without slurry to a pasted strop one should use the coticule with a stropping motion.
As I was reading, i recall that one of the things about Ken's ( i think) products was the small range of particle sizes vs his competitors products wider range... interesting experiments.. would love to try some soon.
--Jon. "Love me some 14s"
I remember my dad had a honing "wet" stone, don't ask for specifications, I only remember it was two colors, one side kinda black, and the other one redish, it was obviously two different grit sizes.
He used it just to hone some kitchen knives and scissors and he taught me that the honing motion should be always edge trailing, but here I saw a few howtos telling you to do it edge forward, which sounded to me a bit harsh for such a delicate blade as the razor blades. Where am I wrong? Did my father have a misconception regarding blades honing?
My guess is he had a synthetic hone of some type, possibly the bottom one on this pile of Norton hones.
but this is a guess.
Honing spine first is a common mistake or misconception. I am sure it is rooted in a practical reason because the practice is so common. My Dad taught me the same way. I was retaught by a friend's dad when I was in high school, but still switched between edge or spine first till I started honing razors. (My wife was taught edge first by her grandfather, an acomplished machinist, I stopped honing around her to keep peace)
Near as I can figure honing spine first generates a burr more easily. Honing spine first also gets better results using low quality stones, some natural sand stones, and low quality coarse synthetics have larger particles that can damage the edge going edge first, but won't do as much damage spine first. This is just my thoughts, I don't have support other than anecdotal evidence from my Dad.
With the fine to very fine grit hones we use on razors, natural or synthetic, there is a level of quality control to prevent faults that can damage an edge from being sold. Honing edge first tends to prevent burr formation, even though a burr can still be formed using pressure or a lot of laps on one side of the blade. A burr is simply metal that is deformed and pushed past the edge instead of removed. A burr is not suitable as a cutting edge. A good strong cutting edge is the polished bevels meeting at a fine edge.
Seraphim posted some wonderful pictures of what an edge should look like under a microscope.
Bumping in order to see if there are any updates, and because this thread is epic in its usefulness and geekiness.
It's on it's second of third spritzing of spray. I also have it down to a science where 5 laps on each side get me the edge I like. 5-10 also touch it up nicely as well.
I had been concidering nano sprays prior to getting my Jnat. This thought had totally gone out of my head. Thanks guys, the itch is back.
Kent. what sort of finishing stone do you follow up with the spray. Coti, Jnats or all?
Do you find it benifits using after one more than the other.
I go through a nagura progression, then after tomonagura slurry I do 5-10 on the .1. CBN and .05 poly. Then it's very light heel to toe passes on water. After the sprays it pops HHT root in, and after the laps on water it's about the same.
Shaving with that edge is very close to a feather AC blade. It might be too keen for some, but it's a pull free ATG on most of my face.
It also ups the keenness on a coti edge as well while keeping the smoothness. One caveat is if a blade is sharper, it will necessarily require a lighter touch
Well, I got the 0.128 CBN spray and proceeded to use it in one of my two new DIY Tony Miller like en strops. This first experiment was a disaster as I ended up rounding the edge on my Ti Gd shorty srt8. last night I finished re-honing the edge
I find little things like that inspiring. It goes to show that even someone at their home with an idea can break new ground in areas (=
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