Thread: Cotis v Japanese Naturals v. Guangxi: A single-blind, repeated measures experiment

First, I apologize for the anticipated length of this post, and the fact that I'll be doing it in installments. I'm a physician raising a child and trying to keep SWMBO reasonably content and away from my Mastercard statements, so it'll probably take a good part of the July 4th weekend to get this done as I would like.

I recently deposited a goodly sum in Old_School's bank account for two Japanese naturals -- a Nakayama Maruichi Asagi and a Nakayama Maruichi Kiita-Asagi mix. I wasn't unhappy with my coticules, and I'd recently (re)discovered the basic goodness that my Guangxi, plus patience, could bring to a razor. But, as I wrote O_S, , I was looking for maybe a 2% imrpovement in my polishing stones which, by my calculation, would deliver edges as close to perfection as my skills would allow.

Other than my love of straights, and an obvious (if diminishing) excess of disposible income, the only other fact of interest about me in this context is that before med school I earned a Ph.D with an emphasis on statistics and experimental design. So, I decided to figure out, as objectively as possible, if I had achieved that 2% improvement.

The Stones I have several coticules, among them a "La Veinette" hand selected for me by Bart, which he told me had a reputation (the vein, that is) for fast cutting and preliminary work, and a 6X2 I usually use for finishing. Since we all know coticules can vary, I thought this would represent the relative extremes of their capabilities, although in truth I wasn't very pleased with the "La Veinette's" aptitude for rough work. I included the 2 Japanese naturals, obviously. I also included my Guangxi. I would have loved to include an Escher, but I do not have one.

The Razors Certain razors love certain stones? Not so sure about that, but I chose razors that represented a range of types: a 6/8 Grelot 1/4 grind, a full-hollow tortoise 5/8 Dovo (the lab rat of honing experiments), a near-wedge Wostenholm, and a singing blade Genco Master Barber. What all these blades have in common is that they are easily honed and require no special considerations.

Soaps In a way, this was the most difficult part of the thing for me. For consistency's sake, I wanted to keep one soap through an entire rotation of the razors, and I love to use different soaps from one day to the next. So I chose several I like well enough to keep me happy for several days running, and that always work well for me: MWF, Williams, Tabac, Speick (shave stick milled in a bowl) and Prarie Creations. (As an aside, whenever I read a thread wherein individuals are trying to outdo each other criticizing Williams, it always registers in my brain as a conversation between "players" each proclaiming that HE is the most awkward around, and least adequate at entertaining, a beautiful woman. A weird, yet always amusing, argument. At any rate, the Williams provided me with an abundance of well-hydrated, thick lather, as always.

OK, my son wants me to come down and watch Hot Tub Time Machine, so I'll sign off. Next I'll describe the procedures I used. Last, I'll give the results and conclusions. Hope this is of some interest.

Great thread and highly interesting. I look forward to reading your results. Im familiar with cotis, but Jnats are completely alien to me.

SWMBO is about to make dinner, and has decreed that the DVD must follow said dinner, so I'll push on.

All four razors were capable of delivering great shaves prior to participating in the experiment. Each was honed on a different stone and then used for a full shave at some point over the next several days. This constituted one "rotation." Because there were five stones and four razors, five rotations were required. One soap was used throughout each rotation.

Wait a second! I thought you said this was a "blind" experiment!

It was, by grace of my poor memory. Come shave time, I could never remember which razor had experienced which hone. Whatever cognitive gifts I have, a memory for this sort of thing is not among them. Five minutes after I hone a razor, unless I write it down, I won't know how I got it done. Lost in the moment, I guess.

At the end of each shave (more exactly, one hour post shave), I evaluated the razor's performance along 2 dimensions -- comfort and closeness.

Comfort was evaluated in 2 ways. One score was based on the amount of "sting" elicited by my alum block. I keep a shaving diary, and always rate this on a scale of 0-4, with gradations (i.e., 3+, 3+/3++, 3++, etc.), so I'm comfortable and familiar with this system. The second rating was simply how comfortable the shave seemed to me while in progress. Interestingly, these two scores did not seem to correlate very well.

The closeness scores require some elaboration. I can always get a BBS shave. But this almost always requires touch-up passes in four "difficult" (for me) areas -- my upper lip, lower lip, under my chin, and along my jawline. Obviously, a series of BBS shaves would not differeniate between the hones. So I decided to forego the touch-up passes. Just my regular shave, then evaluate the four "problem" areas as follows.

Score of 4: No stubble detected with firm pressure ATG

3: No stubble detected with mild pressure ATG.

2: No stubble detected with light touch ATG.

1: Stubble detected with light touch.

The razors were honed for 100 passes on each hone. Why 100? First, I needed some uniformity here. Second, 100 seems to be in the accepted range by many experienced with these hones. From what I read, 100 may be a little short on the Guangxi, a little excessive with the Cotis, just about right for the J-Nats. Thrid, these were all natural stones without a reputation for overhoning, so at least 100 would not be too much in that regard. Fourth, there had to be a sufficient number of passes to erase the "signature" of the previous hone, and I thought 100 should do that. So, I settled on 100, but I understand this may not necessarily hit the "sweet spot" for each hone.

All the stones were used with H2O only. Again, the razors were already plenty sharp, and the procedure was designed only to asses the stones' final finishing qualities. I know there is some debate about using slurry with the J-Nats even in the final polish, but I accepted O_S's expert advice on this, and did without.

I decided not to strop after honing, in order not to mask the edge provided by each of the hones. This decision only lasted through the first rotation, during which I experienced relatively harsh shaves and multiple "weepers," evena few cuts. Up until this experiment, I had always stropped after honing, and I quickly learned that, at least for me, this was a wise tradition. I was willing to make some sacrifices to get the data, but uncomfortable shaves were not among them. So I stropped for rotations 2-5, and enjoyed them much more. Blood loss returned to baseline: maybe a weeper every 4-5 shaves.

SWMBO is ringing the dinner bell.

a nice account of your personal honing and shaving experience.

I have enjoyed reading your report.
Looking forward to more.

Yep! stroping on leather really does bring the edge to a higher level of refinement.

There are so many different variables to edge development and refinement that it can be a challenge for a long time.

Best shave off stones and leather for me has been. Bevel set through normal progression then 40 laps on my Chinese 12k. Let the hone dry for 2 days.
Then hone 30 passes on the dry hone with ever lightening passes.
35 passes on SRD English bridal and 50 passes on SRD premium 1.
One piece of tape was used on the razor spine.
Razor was a Henkels Twin 14, One pass WTG

Regards,
Silver2

We appreciate your taking the time to share your experiment with us. I know we're all anticipating your conclusions.

Originally Posted by pcb01

Wait a second! I thought you said this was a "blind" experiment!

It was, by grace of my poor memory. Come shave time, I could never remember which razor had experienced which hone. Whatever cognitive gifts I have, a memory for this sort of thing is not among them. Five minutes after I hone a razor, unless I write it down, I won't know how I got it done. Lost in the moment, I guess.

I think I'm missing some of the concepts of your experimental design. You're basing your objectivity on poor memory, but if you're not writing it down, how are you keeping track of which razor was honed with which hone?

I have the same problem with forgetting what I honed a particular razor with unless I write it down. Shortly after I came around and began honing I made a resolution to keep a honing journal but regrettably I haven't done so.

I anticipate that naysayers will post that your experiment is unscientific. I am not qualified to judge but I too am enjoying it and look forward to your upcoming progress reports.

Originally Posted by Utopian

I think I'm missing some of the concepts of your experimental design. You're basing your objectivity on poor memory, but if you're not writing it down, how are you keeping track of which razor was honed with which hone?

Prior to each rotation, I honed (polished) all 4 blades at one time, and immediately wrote down which razor was honed on which stone. I put away the list, and did not look at the "key" until after the experiment was over and I had to do the calculations.

During the last couple of rotations, I began to suspect that I could tell which razors had been polished with Cotis, but I was never sure about that until the experiment was over. When I checked, I was right. But I wasn't sure at the time, and I don't think it influenced my judgment.

Hope this explains it.

I really like your observations pcbo1 and am anticipating more!

I am very new to J-Nat honing. I do have a question and that is from my observations a J-Natural honed razor has a different feel to it when shaving. One can apply a little more pressure and still get a superlative shave with no irritation at all. I don't think that the edge is quite as keen as coming off a 0.1 micron film but it doesn't matter because one can change technique a tad and probably get a better shave.

Waiting for more.

Thanks,
Richard