J-nat --> Man meets learning curve or poor acquision

OK, so I went out on a limb and bought a cheap (I know, I know) J-nat hone that was going on eBay in my area. It was sold as a Ozuku Asagi Lvl 5+. Told it was very hard, had good finish on water and gave a smooth edge with a minimum of X-strokes.

I've lapped it flat and applied the Tomo that came with it to it and have revealed a surface that mirrors my decor when held at a 30 degree angle and I'm satisfied is flat and ready.

I have a couple of 6/8 hollow-ground (Invicta) Sheffield razors that I've put a satisfyingly sharp and comfortable edge on using my trusty La Veinette coticule. They pass the shave test very well when finished on my coti and I use them as pilot razors for the new hones I've (needlessly) acquired since getting hold of my beloved first coticule.

I've put both razors to the eBay J-nat both with plain water and with slurry.

With plain water, I've seen the scratch-pattern change very quickly with what looks like a straight edge under magnification, but the shave test was very rough, not sharp at all (some tugging, not much cutting power).

With slurry, provided by the Tomo, I got a similar edge under magnification, and the shave was slightly smoother, but nothing like as smooth and sharp as my coticule.

For each attempt finishing on the J-nat, I've used no pressure, continuous, plentiful X-strokes. With slurry, I've continued honing until the edge is under-cutting the light slurry on the stone.

I've had a couple of goes and can't seem to get a nice edge with this stone yet.

I'll provided some photos of the stone when I get it sorted. My questions are these:

- Is there a something I'm missing when going from honing on a coticule to honing on a super-hard J-nat?

- Is there some way to determine, by myself, whether I've bought a flashy paper-weight?

- Is there someone Down Under who would be willing to test this bad boy for me to determine whether she rides?

Cheers! Look forward to hearing from the forum!

Happy Movember!

I've never used a Jnat, however to your question as to if there is someone Down Under who might be able to evaluate your stone you could give Oz a PM and see if he'd be willing to have a go with it.

http://straightrazorpalace.com/members/onimaru55.html

I'd ask him if he'd try the rock and also if he'd try it on the same razor as you have tried honing. Just a thought :shrug:

I know on extremely hard jnats it can be easy to damage/ruin edge if you are not carefull. I would get razor shave ready then just finish it on jnat with tomo slurry. Some jnats finish a lot easier off tomo. Although there is good chance there are bad particles in stone damaging razor.

Hard to tell if it is the rock or your technique. IMHO it is best is to have it evaluated by someone with experience.
Rule of thumb, do not buy Jnats from ebay. Use reputable dealers only.

JNATS are very touchy and not all are razor edge capable as some are tool grade, my testing of a new stone consists of lightly killing the edge then with a medium slurry work it until the bevel is reset then finish, sometimes it takes alot longer than it should but a good one should not honestly take more than 10-15 mins.

My suggestion is put your best edge on with the stones you have then shave with it to see how it shaves then do some water only laps and strop and see what you get then if that yields acceptable results take a DMT or Atoma lapping plate in the 1200 range and work up a light slurry, by using the lapping plate you are only getting grit from the base stone and work the edge down to almost straight water, this should only take 4-5 mins and test shave.

If you've used two known razors and you're finishing the edge all the way to the edge itself, then the shave should be good. A good jnat (that is actually intended for razors) will provide a reasonable edge even on a relatively heavy slurry, and should improve up to and through a light slurry. Some will continue to improve through clear water, but not all (and not all have a good enough feel).

I have found japanese natural stones for very little cost that finish as well as anything I've used, and I've found $600 stones that have desirable visual characteristics that don't finish any better than a good misshapen barber hone. All of the good (fine) ones will make a very even edge and a polished bevel on a slurry that's near clear water.

I would test your stone as follows:
* slurry the surface lightly with a diamond hone and then let it dry (no tomo, the tomo could be the problem, you never know)
* add a couple of drops of water and start honing the razor with moderate pressure (circles, etc, shouldn't matter)
* lighten the pressure and then add some more water, continuing to lighten pressure as you lighten the slurry
* once the slurry is to a very pale slurry with mostly water (but not clear) carefully do a couple of minutes of light circles or 50-100 strokes of whatever your preferred stroke is

linen and leather (or just leather if you don't have linen).

If the edge isn't that great, go to the middle of the process above again, moderate pressure to light and then leather again.

If that fails on razors that you've had success with on other stones, then the jnat isn't that great. If you can't get your money back, either repurpose the stone as a prefinisher and set it aside for another go later on.

In my opinion, a good jnat is easier to finish with and more common than a good coticule (though there's a really bang-on coticule once in a while, and the mediocre ones can still provide a good shave).

Also, jnats that aren't fine enough to polish on a light slurry can still deliver a good even edge and a good shave, but they may require a linen cycle or two to get what you want.

Until I bought a metallurgical microscope and dedicated a couple of test razors, I wasn't really able to separate whether it was me or the stone. The substandard stones don't create the same even defect free edges that the good ones do. Sometimes they're just coarser than a seller says they are, and sometimes they have less than obvious toxic particles (by that, I mean that they have stray scratchers that leave tiny spider webbing that looks OK to the naked eye, but when you look under a proper metallurgical microscope, you can see voids left where those particles terminated at the edge). Those types of stones are better left as something to sharpen pocket knives.

One last comment, the old stones come out of japan in droves by pickers. A lot of them are junk, but there are some real pearls in those piles if you're just looking for capability. I don't know how to suggest finding the good ones without at the same time suggesting buying 50 of them and trying them out. In my opinion, a good hobby dealer will do that, sort them, and then sell the stones that actually work for razors at a reasonable price, sell the other ones as they should be sold (prefinishers, or if they're toxic, something other than razors) and throw out the complete junk. A professional dealer won't screw around with doing that because there's no money in it.

When I see unmarked green koppa sized razor stones being sold for $225 or some such thing, it makes me recoil a little.

At any rate, I'd say of what I've gotten in piles from japan, if someone says a stone is a razor stone and it's not a full sized stone, 50/50 chance it'll be a good razor stone. 1 in 10 or 20 that it will be as good as anything you'll ever see, and about 5 out of 20 won't finish a razor at all with two or so of those being toxic. Just guessing here.

Too with this, most of what I've gotten new isn't that great on average. OK, but the three or four best stones i've gotten out of a hundred or so have been nondescript (one of them did have an older stamp on it, but it wasn't any of the current oft copied stamps). Bayamontate on here has one of them.

Thanks for the helpful replies!

cudarunner -> Thanks for the suggestion, mate. I'll get onto Os and see if he can help me if I can't get any love from this stone.

Mainaman -> I know, I know. eBay stones are all best avoiding. I have salivated over stones on dealers websites, but always figured that a fine J-nat was cost-prohibitive for me, especially given I've liked the shaves off a coticule. This stone, however, came up on an eBay page from a local honer and vintage razor seller whom does come recommended (though, again, I know that doesn't mean he necessary knows his natural stones) and I was pleased with the idea of picking up a cheap J-nat. I guess I figured at the time that if I couldn't get it to work as a razor-finisher, I could at least use it to polish my knives (which I assume I'll be able to if it turns out this is more of a tool-grade stone).

Dave -> Thanks for the detailed response! I'm in the process of breaking-in a DMT, so I'll take my test razor through the motions you've suggested when I have a bit more time on the weekend (so far, I've been using the tomo that came with the stone to raise a slurry, which, as you say, may be the problem).

I'll keep you posted on my progress with this bad-boy.

SUCCESS!!!

As suggested, Dave, I got my (now broken-in) diamond plate onto the stone, raised a slurry and worked my way from circles to X-strokes while diluting to a pale slurry.
By the end of my first attempt, I was tree-topping hairs on my arm, so I stropped on linen, then roo leather. I ended up going through another set of X-strokes with a lighter slurry with more stropping to follow before taking it for a shave.
The edge I've gotten from this attempt is at least as good as if not better than the best coticule edge I've put on my test razor in terms of keenness, closeness. The shave itself left me with a bit of irritation on the neck from the against-the-grain pass, which wasn't quite as smooth as the coticule edge (I have sensitive skin, hence the coticules).

I'll have to keep playing with it and see if I can improve the edge, but all-in-all I'm chalking this up to a win given I haven't before been able to put a shave-ready edge on a razor with this stone before. What I've done differently that seems to have worked is not using the tomo that came with it to raise slurry and finishing on a thin slurry, not water.

Thanks for the input!

Here're some photos of the stone to follow. It's a visually very pretty stone, I'm glad it's worked for me, too.

Attachment 279170 Attachment 279171Attachment 279172

Little update:
I've graduated from my practice razor to another 13/16 modern Sheffield (also an E. M. Dickenson Invicta) I've restored. Used the same method as above, getting to pre-polisher stage with coticule after a Naniwa 1K bevel-set. Just had a test shave, and it shaves like a dream. Very keen, still very smooth. Definitely not the smoothest shave I've had, but I'm glad I've now got this option as a final finisher.

Thank again for the help!