Discussion in 'Straight Razors' started by Steve56, Mar 21, 2019.
The ‘New Year’s Enjoy Bags’ arrived. Let the de-oiling begin!
How to Pick a Toxic Jnat Line, Hard and Glassy
Here’s how to manage those pesky glassy lines. Not all of them are toxic, most of them just wear down with the rest of the stone. Once in a while though, you’ll see one strong enough to resist wearing and with use, it will stick up above the honing surface. Not good. You’ll need a carbide scribe/pick and a fiberglass brush, image 1. The line on the stone in the image is only about half toxic, the other end of it isn’t, but may well be with time and wear..
You cannot drag a scribe or pick along it, it’s higher than the hone surface, hard, and the pick will just skate off the line and gouge the hone, then you end up with a mess with the line still there.
Image 2: Begin by de-stabilizing the hard glass stuff by holding the pick straight up. Push straight down until the hard material gives. You’ll have a tiny dot or divot right on the line. Repeat this until the line is covered with overlapping divots. The line is now probably below the hone surface and you’ve not removed much if any hone material. Now you can very lightly hold the pick vertical just like before, and move the tip along the divots. What you’re doing is breaking out any material between the divots. Do not use heavy pressure, it isn’t needed and could cause the pick to skate off the line and gouge the hone. Now you should have a very fine line that’s lower than the hone surface. The line in the images is already done so that’s sort of what you should be seeing.
Image 3 and 4: Now you can - again with very light pressure, go along the line with the pick at a 45 degree angle, first one way then the other. What you’re doing is removing any unstable material from the top corners of the line. You want the side of the carbide insert to push on the corners of the line, you’re not so much using the tip. Repeat with the tips of the fiberglass brush against the line top corners and you’re done.
Afterwards I like to take a Mikawa nagura and raise a thick slurry and just rub the area with the line. The idea is that the slurry will smooth anything left. TBH I don’t know if this is really useful but it won’t hurt.
You’ll need to check the line every time you lap the hone and see if it needs further maintenance. If it gets up flush with the hone surface again, repeat as necessary.
Well this is interesting. Those ‘new’ stones have been used with something, they look like they’ve been used with the yellow honing solution, but it doesn’t smell the same and the alcohol in my test piece is only slightly colored. It has a very musty smell that you can smell on your hands if you handle them, and it seems to have a slight anise note to it. Mostly it smells like old garage or shed that hasn’t been cleaned in 20 years.
I had to re-seal one of the bags and the alcohol is removing it, I could smell it on my hands from the alcohol. It also seems less water soluble than the yellow stuff. I think that I’ve smelled something like it, and darned if I’m not thinking Ballistol, anise scented thin mineral oil that can be used as honing oil. Time will tell maybe.
The Jnat game is fun but sometimes it's painful. This nice karasu had a bunch of bias cracks. Not the nice stable ones but the ones that move quickly and when you push on the stone you can see the water come out of the crack indicating instability. The sound of the stone when taping on it was also off towards the one end. This was what happened next. A whole chunk of the stone came off.
That’s some serious pain and anguish there, @alex1921 Alex!
yeah the pic is from early November. I lapped it down and it's flat now but who knows what's beneath the surface.
I feel your pain Alex. Note my signature, there’s a si ilar reason for it.
Aha. Now I get it.
Here’s a suggestion for fixing pits and void space cracks in jnats, automotive lacquer putty. This is a fine grained nitrocellulose lacquer putty used to fill in small defects in Bondo and paint. I’ve tried it some but not extensively and so far it works, and it should be reversible with a little alcohol or similar solvent.
I’ve seen this before on auction stones but never really tried it, but it’s raining here and supposed to rain for days, so off we go. First we need a suitable test victim. That’s a very yellow, very fast kiita with 5 pits in it of various sizes. Alex Gilmore says these kinds of pits can be toxic, fortunately these are not. A razor nose or toe will catch on them though if using rolling x strokes, and although I haven’t damaged an edge, feeling a razor hang on them is not a pleasant feeling! So I had been using it only with knives. And it’s an excellent knife finisher. It will make a decent shaving edge with good technique, but there are better final razor finishers. As a razor pre-finisher, it has everything it takes, so it will be nice to use it with razors.
I could try to lap these out, and the stone would be more valuable if that worked, but there may be more pits in the stone - or not - and the two bigger pits are deep, about 1/8”, so I’d lose a lot of nice material. I’d also thought about lopping the end with the pits off and making a shorter, purer stone, but that’s destructive - you can make ‘em smaller, but you can’t make ‘em bigger. Just like straight razors.
Image 1 is a picture of the problem. These kinds of pits can have glass/quartz in them, but these don’t, but it’s still prudent to stabilize the edges of the pits with a fiberglass brush after lapping to remove and thin or unstable material, and of course you should take a pick or toothpick and clean any sand or debris out of them.
Image 2 is the stone with unlapped red lacquer putty on the spots. It took 2 applications to fill the large pits, lapped between the applications. Let the putty dry well, it shrinks when it dries, but is otherwise stable.
Image 3, et voilá, ready to go. I’ve tried rolling x strokes and no problems so far.
This one is one of the living edge stones you mentioned Steve. I never thought about it but it makes sense based on kawa on all the sides excepting the honing one. Kiita iromono. Softer stone but seems to be pretty fine. I did a razor touchup and so far it passes HHT5 both ways and tree tops like crazy. Curious how the ultimate test, shave, will go.
This stone is defective. These spots are toxic and will never go away. Typically, such stones are dumped at auctions cheaply.
I know what I'm talking about. The stones in the photo were 25mm thick ... now 5mm.
About kesuji. This is common, especially in suita. Along the edges do not touch them at all. In the center they look at the situation. You can make a furrow with a regular nail. It's not a problem.
Welcome to TSD!
The spots are not toxic.
Toxic in the beginning, doesnt always mean toxic in the end. Way to work it out. You didnt need another Nagura.
I am a big collector. These spots are ALWAYS toxic and often do not go away.
Yes, sometimes they disappear. My example above showed that most likely not.
In any case, the sale of such stones is a bad tone.
In the photo there are various suitа. They have lines and spots, but they are small and I don’t feel them, there are no chips in optics.
There are places which are better not to go, but it is easy to perform, if the good stone, it's bearable, but there are things that can not be tolerated.
They are not toxic, you are wrong. They can be, but these are not.
Beautiful stones. What is your history with shaving and hones?? BTW, welcome to The Shave Den.
Looks like a brick, it is so big.
That’s a beauty @alex1921 !
My story began at school when my grandfather gave EDACO and his sharpening kit.
Now my favorite is Japan. I am delighted.
optics will show everything
Agreed! But not the stone optics....
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