Fixing an ancient Japanese Sumitsubo (part 1)

I was fortunate enough to find an old, antique, rare or ancient (pick your definition of old) sumitsubo on ebay from a seller in Japan.  You can buy new ones in wood from several places in the US, Canada , England, Germany and probably most industrialized countries as japanese woodworking techniques have become popular outside of Japan over the last 30 years.  The one that I bought is complete except for the pin, and was definitely well used!  Before we look at the one I bought let’s look at some others.

Japanese woodworkers mark their measurements on wood from the center of the wood instead of setting a reference edge in western woodworking. So from the beginning when the rough log is being dimensioned into lumber a “tategu-shi’ pays attention to the grain and makes the wood accordingly. The ink used in the sumitsubo is traditionally black and is waterproof.

When marking wood for cuts whether finished or rough lumber, a traditional japanese woodworker uses a Sumitsubo translated as ‘ink pot’ to mark the lines using ink that is waterproof. In addition, instead of using a pencil they will use a small piece if bamboo cut to look like a basic pen that they dip into the ink and write or mark on the wood that way.

Much like western woodworkers are encouraged to build their first tool caddy, tool box or tool chest as a rite of passage. Japanese woodworkers will make their own sumitsubo. Now in these times as traditional ways struggle to survive in so many fields, there are ready made sumitsubos’ available in the traditional style and (shudder) plastic ones.

The following photos are from the blog fabulaignarius which is an excellent source of on japanese woodworking btw.  Below is a picture if a very traditional sumitsubo.

and another that the author at the fabulalignarius blog made himself:

A more ornate one is shown below:

And another example of one made by another North American woodworker.

Now for the sumitsubo I bought.

Other the years the ink in the well, the left part of the sumitsubo has covered the entire body.   The ink well contains silk which the woodworker puts ink chips on and then puts water on them to make the ink liquid.  A silk line is wound around the wheel and goes through a small hole, through the silk and ink and out a hole at the from of the sumitsubo, where it is connected to a pin.

Dark as night, in the bottom right is a piece of the silk string that is impregnated with ink.  Wonder how old that silk line is?

I noticed when looking at the wheel that is narrower at one point and then discovered the two cracks in the wood top half of the wheel.  Time for a repair!

Using some wood glue, I carefully put the glue in the cracks on both sides and the spoke in the middle of the picture.  Fortunately the wood had not broken all of the way through.

Oh well so much for my careful gluing, I forgot that this particular glue likes to foam.  Oh well that can be fixed later.

Finally, I used a small wedge to prop up the piece so that all of glued pieces touched and stayed in place,  Now we wait 24 hours until it sets.  In the next post I will show you the repair and the sumitsubo in action.  Until then, cheers.

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