Monday, November 10, 2014

Diagonal Chumasaru — jointing and sharpening

Today I was playing again with yesterday's saw.  

I sharpened and gave it a try, and was blow out for how fast it cut. It's 3.1415 times better than my universal kataba. And cheaper. 

It was nice, but the ripping teeth ended up far to low, so I was only looking at the effect of the deep gullets. Anyway it was cool, but I wanted to try the real shit. 

So I jointed down till the ripping teeth height, and sharpened again. And touched the gullets with a needle file.

I'm still learning how much you need to file down the front and back facet before touching the third eye, so the teeth are a bit chubby for my taste. I like em skinny and blond. 

Anyway, here it is. I hope to give Jason more reasons to confuse my saws with the one from Nagakatsu. (Are you sure you don't need glasses?) 



Here is the other side: 

This is how it looked when I jointed them. A lot of more filing than what I was expecting, however, I think it was well worth it. 

 For sure, this is the sexiest diagonal cut saw I ever tried. Not that I've tried many, but boy it goes fast compared to a cross cut. 

Next in the pipeline is a gents saw that will get a japanese haircut and home made azebiki. Maybe. 

Anyway, it feels pretty damn cool to have a saw that you cannot buy in ebay. And being able to make them feels even better. Give it a try. 


  1. Haha haha! It is true, I have terrible vision........but now you've made it even harder to tell them apart!

    Your blog keeps getting more and more interesting!

    I think that there is a desire for more in-depth information regarding Japanese saws (beyond us that is, haha!). The used market abounds with cheap, old saws, but many(most?) of us don't really know where to begin when choosing an old beater to fix up and use. You have already done much, not only showing us how, but also giving us some amazing inspiration and some great new ideas.

    Thanks for sharing this with the wider world!


  2. You are welcome Jason,

    I guess I will have to make a post then with an old saw from start to finish. I hope to get a few more from Gary this week.

    But a short answer would be: Get whatever you can find. Pretty much any steel will cut wood, even if not hardened (I will make a scraper saw to show that). If it's bent, straighten it or cut it in half. File teeth once, twice or ten times. Each time they will get more consistent. And it takes long to spend a saw, so you have plenty of practicing. Before all that, build the japanese saw vice, I cannot stress how important that is.

    And finally, don't believe Odate nor the japanise, you don't need to be a metate to sharpen your saws. It's exactly the same as kanna sharpening, you just need to practice. The thing is, it takes much more time to dull a saw than a kanna, so as a carpenter you don't get enough practice unless you are like me and buy saws for the sake of it, or file them again when they are still ok. At the end, your body just needs to develop and expand the sensorimotor loop between hands, eyes ears and mind to keep a file in the same angle as you move it on space. Pretty much the same as keeping a chisel at an angle in the whetstone.

    (I don't know how much of that is still valid for the blade straightening tho, the causality of hammering a sheet of metal and its deformations is something completely alien to me still...)