Thread: J-Nat club

Originally Posted by DaveW

question for the guys with hatanaka stamped stones. Is it implied that when you get one of those stones with stamps that they're gone if you lap it? That may be a stupid question, I can't imagine that they go below the surface, but so many of them still have their stamps in tact that I'm guessing that means they're never used seriously.

Yea I believe the stamps will be gone as soon as they're properly lapped. I know some sellers only use very small portions of the stone to test for hardness, fineness, speed etc. That could be a way they retain their stamps.

Originally Posted by DaveW

question for the guys with hatanaka stamped stones. Is it implied that when you get one of those stones with stamps that they're gone if you lap it? That may be a stupid question, I can't imagine that they go below the surface, but so many of them still have their stamps in tact that I'm guessing that means they're never used seriously.

Yes, the stamps will be gone after a serious lapping or use. That said, I've had a few that were flat enough to smooth with fine sandpaper, say 1000 grit, and got away with the stamps remaining somewhat legible.

Cheers, Steve

2 Yaginoshima Asagi from Hatanaka. Stamps went on first lapping.

After lapping. To the person with the stamp question. I will hone around stamps for awhile if the stone is flat. Even using a tomo over stamp isn't usually a problem(depends on stamps though). Some hold better than others. Stone I showed one page back still had stamps, but with the stamped area having some oxidation and high spot I lapped flat and they look even better without the stamps sometimes.

Originally Posted by rideon66

After lapping. To the person with the stamp question. I will hone around stamps for awhile if the stone is flat. Even using a tomo over stamp isn't usually a problem(depends on stamps though). Some hold better than others. Stone I showed one page back still had stamps, but with the stamped area having some oxidation and high spot I lapped flat and they look even better without the stamps sometimes.

Dang that's a pretty stone!

Whether the stamps have to go depends on the particular stone. Older Hatanaka stones may be flat enough to be smoothed with 600-2000 grit paper without completely removing the stamps, I have a new-old one like that now on my bench.

I think many of the new old stock are a little high in the center which maybe isn't that bad a geometry for a hone though flat is better if your razors are also flat.

The reason that they're slightly high is described by Iwasaki-San in his paper to barbers, hones lapped with loose grit on a flat surface will end up a bit high in the middle. I don't understand why really, but he is right. They used something like a cast iron wheel with loose grit to lap them at the mine/wholesaler.

Cheers, Steve

The reason why so many old stock stones appear to have fresh stamps, is because they are fresh stamps.
Many stones are still lying in piles without stamps; before they're sold they are stamped with old stamps

These stamps would disappear more quickly after flattening, whilst the really old stamped ones could last longer

Originally Posted by DaveW

question for the guys with hatanaka stamped stones. Is it implied that when you get one of those stones with stamps that they're gone if you lap it? That may be a stupid question, I can't imagine that they go below the surface, but so many of them still have their stamps in tact that I'm guessing that means they're never used seriously.

I have 3 Hatanaka stones , they all lost their stamps after I lapped them.

On the subject of stamps. Here is one that was stamped decades ago and the ink had penetrated into the stone. I have used it for several years and lapped it quite a few times. The stamps were still visible. The first picture is the stock picture from the vendor, the others were taken at different periods of time when I owned the stone.

I think there are a few things at play here the age of the stamp is definitely one the color and type of ink, but also the hardness of the stone too. Just like water it will be harder for the ink to go deeper on a harder stone, but it would also last longer on a harder stone that was stamped long ago due to the stone wearing slower. On newer stamped harder old stock stones sometimes just water and wiping dry will take off most of the stamp.

Ohira Renge Suita, started as an almost pure Shiro (white), but once lapped, not so much anymore. Most of the surface is Su-free (Sunashi) like in the last picture, but there are a few spots with Su, so technically it's not a Sunashi at all. Time will tell what properties this stone will reveal, but for now it's a hard, fine piece, moderately fast on slurry and slow on water, reminding me of my La Veinette coticule.

Other characteristics (and why I jumped on it) show chisel marks on the bottom, tiniest bit of skin, and saw marks on the sides.. One line running through, I've not tested it thoroughly yet to see how hard or soft it is. I've finished a razor on it today from 1K, gonna head off to shave and see how I've done.

Cheers!