Thursday, December 26, 2013

Frankenstone!!! ( broken Tsushima waterstone repair)

Merry Christmas!

It was the week of Christmas and I really needed to get some things done. Why do we wait till the last minute for so many important things? I had gotten two old chromolithograph prints for Renee about three months prior, intending them to be Christmas gifts. It's not like this was a last minute purchase or something, but I DID need to make some frames. That WAS last minute.

I bought these 100 year old prints from Rudy at Geological Specimen Supply and they are soooo cool! Thanks Rudy! He sells through Ebay as nightlights42 and is absolutely top notch. Buy stuff from him (and he sells rocks, too)!

My *ahem* medical condition makes travel a bit uncomfortable (and I hope to be able to use that excuse for as long as possible!), so while my family was away on Christmas visiting family, I had other projects in the works.

Remember this?

These bits and pieces of rock are actually the remains of a large Tsushima black nagura waterstone. They were evidently mined from an underwater mine (really??), years before and have some nice attributes (very fine, even grain with no inclusions, medium hardness and good slurry production) and some not-so-nice (a pronounced tendency to fracture being most notable). This was from the last of a large lot of Japanese natural waterstones that Ebay seller stellers_j has been auctioning off for the last 6 months. If the pieces were 40mm cubes, the bidding would have gone higher because then they would have been in a more recognizable form/size. Full size stones sell for $200-300, 40mm cubes for $30 or so. As it was, I was the only bidder, go figure......

Most, but not all, of the pieces are there and the breaks are clean. Perfect for Super glue! It's funny, I used to hate this stuff, now I use it all the time. Maybe they improved the formula or something. Anyway, it is dirt cheap, flows into thin cracks by capillary action and does a good job of sealing end grain and hardening wood. The loctite was a "plan B" and was not used because the super glue was....


Not bad! 5000 'ish and very smooth. Definitely a keeper.

Depending on the porosity of the stone, you may have uneven wear at the adhesive seam line. That is the case with this stone, but it's not bad at all. The are a few chunks absent and it would be nice to add some sort of filler to balance out the shape, otherwise the top third of the stone couldn't be used very effectively.I had the plan of filling in some of the missing areas with an epoxy/something blend but after performing a few different tests using epoxy and silica thickener, wheat flour, and pulverized ODC nagura respectively, I decided to go a different route. The epoxy+additive was just too rubbery feeling and wore WAY differently from the real stone. Sacrificing one of my synthetic stones would be one option. Or.....

We have a number of these sandstone concretions laying around the yard, and I found one that was about the same grit and density as the black tsushima nagura. It even had a fossil snail shell in the center! A little bit of artful carving, using the diamond wheel grinder and some 5 minute epoxy (harder and more brittle than the good stuff, perfect for this function)........

 Ladies and gentlemen..... *scary music*...

FRANKENSTONE! Oldschool fossil style. Top.

Bottom. Three pieces were added here.

The line in the middle is from the burnishing action of the epoxy, kind of like a leather strop. Black tsushima nagura finish on the left, fossil sandstone on the right. Almost identical. Amazing.

The wear rate is similar, with the sandstone being just slightly softer, and both produce slurry. The black tsushima slurry is smoother, also more abundant. The sandstone FEELS slightly rougher and sounds different in use but finishes almost identical. No scratchy bits *touch wood*.

The epoxy filled areas are thankfully minimal, although as time goes on I'm sure that voids will appear. I did spend a fair bit of time fitting the pieces. It would have been preferable perhaps to just cut flat-plane surfaces, as this would have been faster and more efficient and also resulted in the thinnest possible glue line. It wouldn't look as cool though and this whole project is the antithesis of efficient, so there. The feel of the epoxy is mildly annoying, but for this price I have no complaints. Just use it like a normal stone and hope that the neighbors don't show up with torches and pitchforks, screaming for blood.


Even though this stone is now all shot through with glue lines, the stone type is still fragile. This would be a perfect candidate for a string-wrap, as are many other aoto's. Give me a few days to enjoy the fossils before I cover them up. I'll take pictures.


  1. Jason,
    I've been following your blog for awhile and I finally decided to leave some comments. I thought I was the only person in search of various forms of sharpening media. I have have a set of Japanese water stones ranging from 220 to 6000 grit. The results are predictable of course but where is the fun that. For about a year I have been researching and collecting various types of natural stones form America. I have a few Hindostan stones, slate, and a few Arkansas stones. I have recently purchased a few Japanese natural stones as well. Per your suggestion, I also ordered some Tuff from Geological Survey Supply which works as a great slurry stone. Keep up the good work and I look forward to reading your next installment.

    Your fellow Japanese tool enthusiast,

    Brian Williams

  2. Happy New Year Brian, and thanks for your comment!

    It seems as though we are members of a small and strange group, eh? Surely there are some stones out there that have our names on them... we just need to keep looking. Most of the responses that I get when I ask others for information regarding sharpening stones is (naturally) defined by the parameters of their experience.... usually that is of the 'ol grindstone and Arkansas/Novaculite variety. When I ask about slate or shale, the response is typically "Well, you can't use that, it's too soft!" Thuringian's are slate and have been used about forever, just not so much on this side of the pond. Tanaka Kiyoto has a listing of sharpening stone types and shipment inventories, dating from like 1700, that shows a broad variety of very different types of stone that were in use. Sandstone, quartz, tuffs, slate and shale (mostly silica shales), we have all of those stone types over here too.

    I get frustrated at times, usually when I am sharpening a new-to-me tool that needs a lot of work, and I just want to get the damn thing pointy again. I find myself falling back into mindset of wanting to be "done", rather than enjoying the " now". For whatever reason, the natural sharpening stones help me stay in the "now" and help me focus my attention. I don't know WHY this is.

    Please keep current with your findings! I have bid on a few Hindustan, I just havn't been willing to go high enough I suppose. I would be curious to hear your take on them and how they compare to your Arkies and waterstones. I think that a good soft Arkansas stone needs to be higher on my list, but maybe a Hindustan? I also fear that I may be talking up the ODC tuff too much, but I literally use it every day. I am working on a post that talks more fully of how I am using it. It may be that it causes the stones to work so differently that it actually masks a lot of different subtleties of the base stones.....

    Wow, long winded....Haha!


Like all of us, I am figuring this out as I go, so when you see something that is incorrect or flat out wrong (and you will!), let me know. This is a learning process. Real people and names, please. Constructive comments and questions are very welcome, but hate speak/politics are not! Life (get one!) is too short.

Thanks, Jason