Thursday, November 27, 2014

The creation of value on Marx's theory of labour — restoring a Japanese saw part 1

I would like to write how you choose a good vintage saw in you favourite flea market, say the one in Kyoto, what to look for, what to avoid, and how to get your 3 euros saw back to work in less than 45min.

But since I'm not in Japan, the only thing I can do is to get them in ebay and pray to the goddess of saw making that what I got for 7 euros each included shipping is worth a bit more than that. 

Today I got the package from Gary, and I may have saved some karma on the past because man the saws are sweet. They bent lovely. Two of them even bent the same way in each side... 

This is what I got:

Select the one you want to restore:

And put some water to it. Then stone it for a while.

I'm using the 10 euros small stone from 330_mate, I stole the idea from him also.  After 3 minutes or so:

What's that?

Seems like somebody signed that piece of rust.

 Indeed, that's a signature.

After 10 minutes and 3 visits to the sink to clean the mud, you start to get something like a saw.

What's more, a saw with with deep sen's mark. I have found a correlation between the degree of sen marks a saw has and its bending... the deeper the marks, the nicer the bending, and the nicer the cut, like more solid... difficult to explain.

Once I got slightly tired, I decided to joint a bit the teeth.

 Just a tad. I rather sharpen 3 times at small increments, than one big filing. Besides, I don't care if there are some teeth missing.

 Yep, like those.

After that, I go to the ground and clean the rust from the gullets. I am not sharpening, just cleaning with an old file so I don't put rust on my nice files.

It looks like this. Real fast, one handed, 4 fingers... nothing fancy, just clean that rust out the way.

and yet another view. The guy who sharpen this thing last time was quite good I must say, look at how homogeneous are the flats on top, also the gullets.

 Then I put some WD-40 and call it a day. My right hand started complainig, I still have a non-functional finger there.

The signature again:

And the whole saw. The rust on the rip teeth is because I filed the sides after cleaning the gullets there.
That was 45minutes or so. My 3,38 euros saw became a, what, 10, 20 euros saw? And the only thing I did was to rub a stone on top of it and file the teeth 5 minutes. Once the bandage is out I can sharpen it and I will have yet another fully functional re-sharpenable saw for 2 hours of labour.

True, the blade could be straighter. Now it has a small bent to one side, say 3mm or so out of flatness. But also had it one of the more expensive NOS saw I got from sakura, and they cut perfectly fine anyway. 

But more importantly, at least for me, is the poetic side of it. By working on it, this saw regains its dignity, and the work, time and skill that somebody put on it long time ago will remain in this world for another 50 years or so. The actions of this unknown blacksmith from Japan will keep having effects way after his death. 

A little joyful resurrection — maybe. 


  1. First Sen is relativly straight, held skewed to the blade. The last Sen is relitivly bowed, and held just off parallel. This makes furrows. Sen means "plow". After restraightening, the tops of the furrows are burnished, or polished - "miyagi", same verb as brushing teeth as in oral hygiene. then the saw is straightened again, teeth are set, jointed and sharpened. Then the blade is straightened again.

    1. is the miyagi done with a file? I've seen videos where something like a ring-file is used with a long handle. I was thinking of cutting pieces of a feather file and weld myself something like that.

  2. The reason this is done, is friction in use is reduced, and this (and the process of setting) work hardens just the surface, which means the burr breaks away with less ductile bending - more like glass - just where a cutting edge is created, sharper and longer wearing, yet still easily sculpted to correct shape.

    1. If I follow you, that would mean that using a file to clean instead of a polishing stone leaves a better cutting saw? That has been my impression lately. By the way, when I file the sides of the saw I manage to get some of those curly shavings, is that the mark of work hardening the surface?

      Or another example, the small dai cutting saw I made was 10 time better after I filled it. From factory it came ground and highly polished, looking cheap. The filing leaves a different, nicer texture. At least it looks like and it feels like, but I'm not very sure yet.