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Show us how you use your natural japanese stones (101)

There may be hundreds of ways to use a Japanese natural stone to hone a razor, partly because they are so different from one stone to another. Beyond learning about the origin of the stones, when honing razors you pretty much need to approach each stone as a study in itself which can be a challange and fun at the same time.

One technique that I found was to use dried slurry from a Jnat asagi stone to charge a plain clean leather strop that was laid flat on a table. Stroping both sides of the razor with no slack in the strop I was surprised at how quickly the razor brightened up and the scratches from the 1,000 King stone were completely removed. Here are the photos of the razor seen at 300x in my microscope.

Do you have any other ways to use a Jnat?

Alx


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Steve56

Ask me about shaving naked!
Hi Alex,

I've used Jnat slurry on a Kanoyama canvas with mixed results. Preliminary edges were extremely sharp and aggressive, like asagi+. My first guess is that result is from my technique or maybe the particular medium. How do the shaves feel in comparison?

We know that Jnat slurry without the host stone supplying fresh abrasive just polishes - put some on a paper towel and rub polished steel and you will not get kasumi. so maybe when you take the slurry off the host stone, you get a different effect?

Cheers, Steve
 
I messed around with broken slurry for paste on a webbing strop and linen as well. I find that it can work great but at the same time it can create a harsh edge if overused. Latest foray using uchi powder was very good. One other thing I do is I use glycerin (1 drop) in the final finish of a razor. On my suitas water and glycerin, my tomae slurry tinged finish. It does add that little extra for sure. I also have been using a tsushima black toishi for midrange and a hieriyama suita and using the slurries from those on my finisher of choice, The edges are excellent and its a fast finish. Heres one video I did doing just that.
https://www.youtube.com/watch?v=l36p2KTHxSg
 
Bill
You make it look so, so easy. That makes so much sense and a nice video production. So are you suggesting that the grit particles continue to break down?
Alx

p.s. I have that exact same smaller Tsushima black nagura and it mine gets a good workout too.
a


 
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Bill
You make it look so, so easy. That makes so much sense and a nice video production. So are you suggesting that the grit particles continue to break down?
Alx

p.s. I have that exact same smaller Tsushima black nagura and it mine gets a good workout too.
a


Well Ive been trying to say the slurry "changes" to avoid the argument and the "proof" required. LOL. I am still enjoying that finisher I got from you!
 
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My approach is less innovative. I am still rubbing Nagura on Awasedo. However, when at the end of the finish process, why/how is a Tomo more effective than DMT slurry. I have a chunk of Wakasa that was gifted to me and it is so hard that I have to use the entire flat or it scratches. But the slurry is very light, a good thing I think. What happens when the Nagura is harder and maybe finer than the Awasedo? My Nakayama Tomo is similar in this respect.
 
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The slurry "breakdown" or change, is an interesting subject to me. I know there have been some tests done by Todd S. showing electron microscope photos of slurry particles before honing and after that seem to show no or minimal difference in particle size. I have a few thoughts on this subject as well if anyone would care to read them:

There are any number of things constantly changing as we hone on a slurry that could contribute to this phenomenon that many call slurry breakdown. Just a few that I have thought about follow.

The particles in the slurry get rounded off and less "sharp" as honing progresses for a longer and longer time, possibly allowing them to cut a bit less and burnish a bit more.

Particles of steel are added to the mix as it is abraded away from the surface being honed. Whether this contributes to the fineness of the finish/edge I don't know. It seems quite possible that this also helps with burnishing/polishing a bit. This steel also rapidly oxidizes, contributing significantly to the slurry darkening in many if not all cases. Pay attention next time you hone a razor with a stone that uses slurry to hone. Sometimes with some stones the slurry turns more reddish brown (rust) than black, especially on stones that produce white slurry. Sometimes it will turn black first, then fade to reddish brown after a little longer period.

The surface of the stone itself becomes polished by the action of the loose slurry particles, just the same as the steel being honed. This may contribute to reduced and/or finer cutting since the abrasive particles will be more likely to slide instead of tumbling and rolling. This surface polishing also contributes to the stone cutting more finely, the same as when a harder stone such as an Ark is highly polished and gives a better finish/edge.

Someday petals we will have a better understanding of all the different mechanisms at play and what exactly is happening if someone like Todd or Verhoeven digs in a bit more.
 
I look at it like this: whatever happens the edge improves more after it "changes". Whatever that is! And I have used a ruby stone that is much harder than any stone I have and its like a universal tomo. I have one nakayama kiita tomo that works GREAT IMO with all my tomae stones, my suita a piece of okudu suita does the job. The harder tomo to stone would create I THINK! (LOL) a finer slurry than a diamond plate but I could be wrong, I will only say I prefer it to avoid the sake of argument!
 
The addition of the awasedo dried slurry on the leather was just a way for me to see how it affected the steel. I tried to do it on plate glass but it was hard to contain the slurry in a manageable area, but when the dry flakes were in a tight pile I did see some quick cutting action at first, then the flakes dispersed too broadly.

On the leather, what was I seeing take place? The first 5 strokes were the most dramatic because it altered the obvious scratch pattern at the edge. The second and third group of 5 strokes showed me that the grit continued to bite and either was very fine to begin with dimensional wise, or it broke down, or the larger particles were brushed away.

Photo #2 showed what we call a classic hazy kasumi finish, not scratches so much as divots in the steel. The transformation in the finish on the surface of the bevel in just 10 strop strokes from photo #2 to #4 is pretty remarkable in my book. I know that diamond dust on a strop does the same job, and faster. Other oxides will too.

I see this same type to a lesser degree change from #2 to #3 in almost every view after stroping on clean leather for 15 to 20 passes on every razor I look at in my shop. But it usually does not progress further down the bevel with additional strop strokes as you see here, the polish remains more localized to the very close edge portion of the bevel face. I acknowledge this minimal polish to the leathers attributes, be they what they may be. I don't add grit but I assume there is some grit everywhere in a shop situtation that is airborne or accidentally transfered.

There are two things that I propose are happening with additional strokes as I look down at photos from #2, #3 and then #4 . One is that the polish continues further back from the edge area of the face of the bevel with more passes, and secondly look at that elongated larger deeper divot near the edge, it seems to get shallower suggesting that steel is actually being removed and not just burnished.

A huge transition happened between photos #3 & #5 in the polish, but between #5 & #7 with the greater addition of 60 strokes the transition and progression farther down the bevel face was seemingly less in proportion to the number of strokes. Like the action bottomed out because of the loss of girt, the breakdown of grit. Still the polish is happening but it seems to me to remain active mostly near the edge. I believe that from photo #8 I see the indicators of a convex edge in the vanishing shadows of the darker deeper scratches, and if you consider the cutting action of the grit in each succeeding photo tended to be the heaviest near the edge, this could be taken as an illustration of the building of a convex bevel profile.

With all this said, I do want to say that the shave with this razor was too close for my skin.

Alex



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Abrasives used on leather are interesting because they seem to behave much differently than when used on a hard/solid substrate. I think the "give" or cushion in the leather helps a lot in giving a finer finish, as any larger particles will just be pushed back into the leather rather than pushing deeper into the surface being abraded. So all the abrasive particles contact the surface much more evenly. Soft substrates like this tend to give far more even and polished surfaces in my experience.
 
I have a friend who when in Sanjo late last year and visited the Iwasaki studio. While there he asked if they would demonstrate their honng technique. He said that the last abrasive to touch the kamisori after the various nagura was when he brought out this little lidded wooden box which when opened reveled a cushion satin silk. The demonstrator sprinkled a little bit of diamond dust on and finished the razor with just 4 light passes on each side and then he quickly put the lid back on. Josh asked him what was under the satin and he said a layer of velvet. Josh told me the velvet just added a bit of a cushion, and I think also a depository for the diamond after is works its way down through the satin. Josh told me that the cushion was small and about the size of the kamisori by proportion.

Alex
 
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