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Honing On Japanese Natural Hones, an ongoing journal

Well, I went back to the Gotta on the Asagi. It was already at the point where it shaved well, but I thought it might get a bit sharper. Also, there were a couple of pits at the edge right at the heel. These don't interfere with shaving, but I thought I'd take the chance to hone them out. This was done on a DMT D8EE. Normally, I'd go to the Spyderco Fine, then Ultra Fine, followed by polishing either on a vintage Thuringian or the C12K. The C12K (and probably the Thurry too) is actually at a lower grit than the UF (I think), but the edges off the natural stones are generally much more comfortable to shave with. Anyway, I skipped all the steps after the D8EE and went right to the Asagi.

I raised a slurry with a Spyderco Fine. It did raise slurry, but not to the extent in the video of your barber, Jim. The reason is likely to be partly due to the fact that the Spyderco is so flat, and the grit is not much lower than the Asagi, and partly due to the fact that the Asagi is so hard to start off with (not harder than a ceramic stone, though).

I then went at it with the Gotta. It's a long hone, so I used a combination of short circular strokes and long half-X strokes. The slurry did seem to cut faster than no slurry, but not by much. This is likely because there wasn't a whole load of it, and also I was wondering if the Spyderco was grinding down the slurry itself. Still, the scratches from the DMT were quickly ground down.

The blade started to suction to the stone very quickly, but at this stage it wouldn't cut arm hairs. I tried to lighten the contact with the hone, but there was no marked improvement. So I slowly diluted the slurry down to water, at which point there was some catching on the arm hair.

This took a while, and I was beginning to get frustrated, so I stopped and dried off the blade. Stropped it a few times on horsehide and checked the edge. It now cut arm hairs easily. So I tried the HHT (I use my daughter's hair - it's long and finer than mine - and there's lots of it available, believe me!). This was a complete failure.

This was perplexing, as I've never before had my version of the HHT fail once I hit the polishing stones.

So I went back to the Asagi - just with water. I did 10 X strokes at a time and checked the edge before doing another 10. There seemed to be no real improvement, so I stopped again - stropped the blade and put it away.

Later, I taped the spine and went back to work. No slurry just polishing. It seemed to get better, so I decided to shave-test it before going any further. It still failed the HHT, though.

This morning I did a WTG pass with the razor. It was smooth and cut the hair well (no obvious uncut hair). I was convinced that the edge wasn't sharp enough for the XTG and ATG passes, so I skipped them. The razor cut as close as I normally get with any straight (including a Feather AC), but on my face, the proof of a good edge is in the ATG pass.

I brought the razor in to work and looked at the edge under a really good microscope. Boy! The edge is so smooooth! There were still a few flaws where the pits were not honed out completely so I may go back to it again.

So I got a razor with a smooth, sharp edge that shaved well. Still, for some reason, I'm bothered that it doesn't pass the HHT. This is purely psychological, as I don't think the HHT is a good estimate of shave-readiness. The problem is that I can get this razor to pass the test, using other hones, so why does it not pass off the Asagi.

The answer, of course, is probably my technique.
 
In the HTT-article, you can read why a smooth edge needs to be keener for the same HHT-results than a jagged edge.
The HHT is not a fail/pass test, though. It can be correlated to the way a razor will shave your face when finished on your particular hone. You can also use the Thumb Pad Test for the same purpose, but it requires much more experience to read the variations of the TPT than to observe the different HHT-levels. A lot of people don't use these tests, and just await the shave. In any case, as you already mentioned, the HHT must not be considered an independent goal. Don't be intimidated by the lack of HHT response. Perform a full test shave, and judge the edge in all fairness. You can try to use thicker, stiff hair for you HHT, as it cuts easier. Or try to cut it closer to the holding point. The general idea is to find a marker for an edge that will shave well. That wat you can rely on the marker, instead of on a true test shave. It saves time while honing.

I've had good success with Jim's method. I found slurry degradation absolutely key. Dilution to plain water on my Nakayama, makes the edge harsher, yet not keener. Once the slurry is properly broken down, I need to bring it to good viscosity (by adding a few drops of water), and keep it constant. I finish the honing on this slurry. Not on water.
At the initial stage, I don't worry about the edge. I concentrate on slurry breakdown only. The edge acts as a probe: when the edge starts to gain sharpness after the initial dulling effect, that's a clear sign of slurry degradation. From that point onwards, I need to watch out. The edge must keep up with the break down of the slurry. If I allow the slurry to become dry and pastelike from this stage onward, the edge will dull beyond the capabilities of the refined slurry. On my Nakayama, that's the prime risk for failure using this method. I don't know if that is key for all Honzani.

I've also found a way to finish an already keen edge on the Nakayama with broken down slurry. It gives me a smoother edge than water only, that seems almost the same as a fully honed razor on the Nakayama. The paradigm is this: hone the razor to your best shavereadiness on whatever progression of hones you have available. Make sure it lacks no keenness.
Raise slurry on the honzan. Grab a cabinet scraper or some other flat piece of hardened steel. Rub with circles and low pressure on a paste-like slurry till it's all broken down. (I think 10 minutes is probably more than necessary, but I've played safe when I tried this). Remove the scraper (transfer the slurry all to the honzan), add some water to correct consitency to slightly thinner than milk. The slurry looks pretty blackened, which is fine.
Finish the razor with 50-100 laps on this slurry (keep the slurry well hydrated).

Best regards,
Bart.
 
Bart said:
...I've also found a way to finish an already keen edge on the Nakayama with broken down slurry. It gives me a smoother edge than water only, that seems almost the same as a fully honed razor on the Nakayama. The paradigm is this: hone the razor to your best shavereadiness on whatever progression of hones you have available. Make sure it lacks no keenness.
Raise slurry on the honzan. Grab a cabinet scraper or some other flat piece of hardened steel. Rub with circles and low pressure on a paste-like slurry till it's all broken down. (I think 10 minutes is probably more than necessary, but I've played safe when I tried this). Remove the scraper (transfer the slurry all to the honzan), add some water to correct consitency to slightly thinner than milk. The slurry looks pretty blackened, which is fine.
Finish the razor with 50-100 laps on this slurry (keep the slurry well hydrated).

Best regards,
Bart.

That's a good idea, Bart! I've only really used my Nakayama to finish an already keen edge, and have had some success with using Jim's slurry method. But this is done on already keen, coticule finished edges. The times that I haven't had the greatest results, I don't think I let the slurry break down enough, as it was probably too aggressive for the sharp edge.

I have a really worn and pretty useless (for shaving) razor that pretty much my designated test razor. I just use to to test out a coticule's speed with slurry, look at scratch patterns, etc., without the fear of ruining a good razor. I have achieved an AMAZING looking bevel and spine (on the spine-wear) on this razor from using my Nakayama with slurry and doing a lot of diagonal strokes on each side. The slurry actually turns grey very quickly on my stone when I do this, even with a milky, not thick slurry. From what I've been reading, it really does seem like those diagonal strokes with a bit of pressure is really helping break down the slurry, and thus results in that spectacular finish. The razor wasn't sharp, as I was only testing the hone's speed and how it affected the appearance of the razor.

My point is that I could do these multiple diagonal strokes on this dud razor to break down the slurry on the stone, then use this broken down slurry to finish an already sharp razor! I know I'm probably repeating exactly what Bart said....but I'm just realizing how easily I could apply that method with my test razor. :thumbup:

I think I might have found a use for that horrible ground (but good steel) razor afterall! It shall be known as the "Slurry Breaker"! :lol:

Dave
 
Judging by what I've read here and elsewhere, here's what I'm going to try next:

1) Build a thick slurry using a DMT D6E (1200) - I didn't want to use the DMT, but I have to raise the slurry somehow.

2) Use only the thinnest layer of water (I read elsewhere that a lot of water just hinders the honing process).

3) Use even less pressure than before.

The problem with the slurry for me is that the Asagi I have is a very hard, blue-grey stone. So the slurry is grey on a dark background, so telling if the slurry has broken down is quite hard.

It's also quite hard keeping the pressure low, as the blade is suctioned onto the stone (I believe this is the major area I'm having issues). I was trying to keep away from using detergent on the hone, but I may have to.

More things to try, I guess. :rolleyes:

Thanks for the help, everyone.
 
Bart,

How about a "beater" (meaning really not good for much) razor for slurry break down purposes. I'm not sure how much hardened steel I have other than knives and razors...
 
I have just such a beater! Perfect test subject!

Just tried my spike (previously coticule honed) w/ water only on my Kiita--much better results than last time (I'm thinking flatness plays a greater role when water is used), but still pretty unforgiving. Reasonably sharp (I think I'd call it "good, but not great"), but not really much more than a coticule. Broken down slurry trick coming up!

Bart, do you notice any other changes when your slurry has broken down? More suction, for example? I'm thinking steel in the slurry might just mean it's cutting. Same w/ thickness--it could just be absorption. Definitely going to try 10 min to be sure.
 
PA23-250 said:
I have just such a beater! Perfect test subject!

Just tried my spike (previously coticule honed) w/ water only on my Kiita--much better results than last time (I'm thinking flatness plays a greater role when water is used), but still pretty unforgiving. Reasonably sharp (I think I'd call it "good, but not great"), but not really much more than a coticule.
This part confuses me a bit.

PA23-250 said:
Bart, do you notice any other changes when your slurry has broken down? More suction, for example? I'm thinking steel in the slurry might just mean it's cutting. Same w/ thickness--it could just be absorption. Definitely going to try 10 min to be sure.
No. The slurry on my Nakayama looks very deep yellow to orange, when I start out. It changes to a dark mud-like color while honing. When entering finishing stage, I added drops of water till the slurry started to loose its opaqueness.

By the way: after some trials, I used a DMT-C to raise the slurry. That one kept the slurry clean. The DMT-E lost a lot of nickel, resulting in a brown slurry to start with. I don't think it would cause trouble, but I kinda like the initial orange slurry.:)

Bart.
 
Bart said:
This part confuses me a bit.


No. The slurry on my Nakayama looks very deep yellow to orange, when I start out. It changes to a dark mud-like color while honing. When entering finishing stage, I added drops of water till the slurry started to loose its opaqueness.

By the way: after some trials, I used a DMT-C to raise the slurry. That one kept the slurry clean. The DMT-E lost a lot of nickel, resulting in a brown slurry to start with. I don't think it would cause trouble, but I kinda like the initial orange slurry.:)

Bart.
The edge felt better coming off of a coticule. Mine is sort of yellow-orange on a yellow green stone. It does darken w/i 2-3 min, so long as I don't make it too thick. Really interesting point about too-thick slurry undoing the polishing effect. Might have been 1 of my (many) initial mistakes!
 
I've been working on my skills with the N-Asagi these last few days.

I used a DMT 1200 to build a slurry on the hone. Oh my! What a difference it made! With a slurry, this hone cuts really fast. I had to hone out a pit on the edge of my Japanese non-folding straight, and only had the DMT 1200 and the Asagi on hand to do it with.

So I honed out the pit using the DMT 1200, using very light strokes, and then used the DMT to raise a slurry on the Asagi. I honed for a little while (circular strokes), and all the scratches were removed. I looked at the edge under a really good microscope, and it was lovely - not a hint of a tooth.

Unfortunately, it also wasn't as sharp as I like it to be; even after the slurry broke down into a muddy mess.

The issue was that the hone is so hard that the razor (which has a large bevel) sticks to the stone (stiction), effectively causing more pressure than optimal to be put on the razor. I tried adding detergent, etc. to no avail.

I finally had to wash off the slurry and use a very lightly wet hone - which gave rise to a great edge. I shaved with it this morning, and it was very nice.
 
Yohann: have you tried a thinner slurry? That was my problem; I was making it too thick. To wit:

Success! :w00t: Just shaved w/ my spike & it was a very nice shave. WTG was a bit closer than I can get w/ a coticule (but no by a whole lot); ATG was about the same. Maybe a bit closer, but that could simply be my coticule honing being slightly off lately. Felt similar, but not quite as forgiving as a coticule.

I finally figured my biggest mistake out: I was making slurry too thick (for my stone). It would barely cut & probably didn't break down much & then after letting it get even thicker, the dulling effect overpowered what little sharpening effect there was. By contrast, I see metal come off the razor almost instantly doing half strokes. Really obvious. Darkens dramatically too. I kept the slurry about the same consistency all the way through & tried making it just a bit light toward the end (but still keeping a good bit of slurry on). Next I'll try slightly thicker once it breaks down. Could be better or worse (we'll see), but @ least now I have a reference point for a good shave on 1 razor.:)
 
So I have been trying Jim's method on a few razors with my Nakayama, with great success! Before I had it in my mind that I had to dilute the slurry to just water to get the desired keeness, but after reading more in this thread and about Japanese naturals in general, I realized that they behave differently than coticules.

So what I've done so far is start with a decently sharp edge honed on a coticule. My Nakayama seems quite slow, so I don't think I have the patience to do the entire honing from scratch on it. :p I raise a slurry, using my small piece of the same type of stone, and just start doing X-strokes. I've tried with a thicker and a thinner slurry, and I've found that I can get the same results with just a thinner slurry. This is of course on edges that are already decently sharp, so perhaps that's why I only require a thinner slurry. I find that after 200 X-strokes done at a decent speed, the slurry becomes quite dark, and I feel a very nice draw on the stone as it starts to dry out.

I remember Jim mentioning that he associates harsh edges with finishing on water, and smoother edges with slurry honing (on Japanese stones, not coticules). Well I used to slowly dilute the slurry when it got to the darker thicker stuff after that 200-ish X-strokes. I got a REALLY sharp edge, but comparing it to the edges I get now just finishing on slurry I realize that same trend, it was harsher when I finished on water. I still get a very sharp edge when finishing on the slurry, but it's a lot more forgiving and smooth on my face.

From everything I've read about finishing on slurry as opposed to water, every instinct in me was saying that finishing on slurry was not the best option, as finishing on water was always better. Slurry was always said to have a dulling effect, so never finish on it....Well, although that may be true for some stones, it does not seem to be the case with my Nakayama (and Japanese stones in general). I really do believe the slurry breaks down, and my smooth face is proof of that. :p

Another thing I've found is that using this 200-ish (I just stop when the stones starts to dry and the slurry thickends, just basically by feel) strokes on thin slurry on my Nakayama is that is seems to squeeze out the last bit of sharpness out of the razor. On a couple of razors that I couldn't seem to be able to quite get to maximum keeness using the dilucot, I've finished them on a thin slurry on my Nakayama and it tweaks the sharpness just that little bit. But on razors that I've seemed to tweak to maximum sharpness using the coticule the Nakayama doesn't really improve it. So I'm really finding that a coticule edge and a Nakayama edge are quite similar, but it does seem easier for me to squeeze out that little bit of sharpness with my Nakayama, perhaps because it performs a bit slow. I am now thinking that before when I finished a razor on a coticule and shaved, then took it to the Nakayama and it improved and thought I preferred the Nakayama finish, a lot of that was likely due to the coticule edge was JUST a little lacking, due to my honing.

So in conclusion, I don't know if I prefer the Nakayama edge as opposed to the coticule edge anymore, I actually feel that they're pretty damn similar when the razor has reached maximum keeness on both stones. I bolded that part because I feel that is uber-important, as is probably the main reason people (i.e. me before :D) seem to feel the edge is sharper off the Nakayama. I love my coticules and my Nakayama, and I feel that when used properly they can both yield great results, they're just different tools, so keep that in mind when using them. They just cannot be compared directly.

Dave
 
Well, that was a great post, Dave! :thumbup:

I'm going to have to try the light slurry trick. The edge I got on my Norio Japanese straight off just water was a little too harsh for me - sharp, but not as comfy as the Gotta.

Also, you're twisting my arm!! I might have to cave in and buy a Coticule.

The problem is, the Asagi soaked up my money, so I need to find someone who's willing to trade a Coticule for something I have.

:rolleyes:
 
Man am I glad people are getting good results from this. I was really worried that I was leading people off a cliff.

Yay! :D
 
Not a chance: works a charm!:) The trick (as you said all along) is to figure out our stones, that's all. :)

By the by, how's that Honzan alternative working out...? ;) And what is it?

UPDATE: got the problem W&B into shave-test territory!:) The wedge I think I messed up the tape--OK, but not great.
 
Well, using the techniques mentioned in this thread, I've got great edges on all the western straights I've tried. They've been sharp, comfortable and great to shave with.

They also seem to cut hair, not skin. I noticed that yesterday when shaving with my 7/8" full-hollow W&B - polished on the Asagi. The razor slipped a bit and 'dabbed' on my cheek - no cut!! If I'd done that with the equally sharp edges I get from my synthetic hones, I'd get a fine cut.

The only issue I'm having now is honing the Norio Japanese style straight I have. I can get it sharp (it passes all the tests) - but even though the edge looks great under magnification, it's just not comfortable to shave with. It's like I can't find the correct shaving angle with this one. There's more tugging than I'm comfortable with.

Very disheartening.
 
Gentlemen, I am further gratified to hear about your successes. Keep on honing!


Yohann, Japanese razors are made of much softer steel (on the whole) than western razors. Thus the dulling effect that Bart mentioned will be amplified--try 1.) a thinner slurry and 2.) a light amount of pressure to focus the edge on the hone itself. It's what's worked with mine. Other than that, I can just recommend to learn your hone.

I am sorry, I've been working on the hones and getting more info for you, but I had a minor health setback and things took a backseat. But I'm all better now and should have some good info for you soon.

And remember: Hone happy!
 
I'm not totally sure but I'm quite confident that using DMT hone for slurry stone degrades Japanese natural hone performance.
I don't have any Jap. natural hone but I have a plenty of barber hones and I'm already experimenting long time with them drying to restore the best possible surfaces on them.
The barber hones are very hard too and only reasonable way to lapping them is by using diamond hones. And ugly truth is - hard barber hone surface is after lapping it on 1200 DMT hone, NOT smoooth enough for satisfactory polishing a blade. Therefore I buyed a 8000 grit DMT and it was quite dissapointment. Firstly, on the surface of new 8000 DMT are many bigger diamond particles or clued together right size diamond particles bunches what leeds to ugly deep scratches on surface. This problem can be overcome by thorough break-in the 8000 DMT. Secondly, 8000 DMT is very sensible when you using it for lapping hard barber hone and specially when slurry is rising - it will loose the diamond particles very easy. 1200 DMT is not so sensible in that term but my 1200 DMT has already lost about 1/3 it's diamond particles. That means, when you use diamond hone to rise a slurry on hard japanese natural hone, there might be some diamond particles in slurry every time.

Conclusion: when you using diamond hone to rise a slurry on a hard japanese natural hone you probably get not enough smoot hone surface and more or less diamond particles within the slurry...
In my mind, only solution for maximum results is to use a little piece of same hone or little piece a finer hone of SAME kind for slurry stone.
Btw. hard hone can be cut in home quite easy - you need for that a diamond saw blade.

Regards to all,
Urmas

Sorry about my English.

Edit: When you using a diamond hone to rise a slurry on a hard hone and you noticed that color of slurry turns darker, that means that slurry is working heavily on material wich bonding diamond particles with hone metal surface.
 
Well, I agree with some of what you're saying, Urmas. My experience with Japanese hones is brief, but I've been learning how my hone reacts to various techniques quite rapidly. There's still a lot for me to figure out, though.

First: the observation about the dark slurry from the DMT hones is certainly correct and is one reason to avoid the finer grit DMT hones.

Second: I've also had questions about A) the damage the DMT 1200 could be doing to the top of the stone, and B) the possible contamination from released diamond chips.
Since I'm using the coarser DMT hone, I'd assume any released diamond chips would leave gouges in the blade, and would be noticeable; however, I'm not certain how to evaluate the general scoring of the natural hone, and what effect, if any, it has.

One thing I tried is to use a Spyderco Fine hone to raise a slurry. It's very smooth and much, much harder than the natural hone, so there should be no contamination of the hone surface. The high effective grit level on the Spyderco Fine should obviate any surface damage on the Japanese hone.

However, in practice the Spyderco wasn't great at raising a slurry. I'd expect a 'medium' to be better for this, but I don't have one to try.

Another thing: I was worried that the Spyderco Fine would grind the released Asagi particles down to start with. That may be good for polishing, but not so good for speed of cutting.

So the best option, as everyone here seems to agree, would be to use a small piece of the hone itself as a slurry stone. Unfortunately, I have neither a slurry stone, nor a desire to cut my current hone to make one.

The guy who sold me the stone is sending over a bunch of 'little stones' that were sent to him by the original seller of the Asagi. He wasn't sure what they were, but hopefully one of them is a slurry stone for the Asagi.

:)
 
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