Shou sugi ban tests with 2 updates
Well. In this exciting post I turn perfectly good white cedar boards into crispy Shou sugi ban siding.
Shou sugi ban is the Japanese technique of burning cedar planks to make a long lasting maintenance free siding.
It’s a slow process though. As you can watch in this video.
For pictures and more
Playing with fire
First off, doing the shou sugi ban is fun. I watched quite a few “how to” videos online. Mostly by people doing it for the first time. It’s very interesting to get “updates” on some of these buildings. I’ve seen quite a few shou sugi ban sidings that mottle and look like … yuck.
So when I did my boards I made sure I got them well charred. Not alligator hide deep as you can see done online. But, as you see here, crackling about 1/16th of an inch shallow. Its a really pretty surface.
I also was very lucky to find, about two years ago, some Tung oil at a garage sale. This is real tung oil from Circa 1850.
Two board test
I use the tung oil on two of the boards to see what would happen. The oil goes on easily and disappears fast. So I work on smaller and smaller areas quickly spreading the oil with a natural bristle paint brush.
Result! The boards come out super dark black. And you can touch them without any char coming off. As you can see below, you get a deep deep deep interstellar deep black. Sweet.
And as you can see
Also you can see the treated wood is a more uniform black. It also doesn’t rub off. The unoiled wood is shinier and rubs off.
Tung oil is really expensive and the wood drinks it up. So I will look into cheaper alternatives. Perhaps experimenting with soya oil.
I have now done an experiment with Soya oil from the grocery store. I mixed in a little kerosene (what I had on hand) to help it spread better. The Soya oil gives the same deep uniform black. However it does not dry as quickly as the Tung oil. I have rested the test boards for a week and the oil is still soft. Patience grasshopper.
I am leaving the boards exposed face up to wind, sun and rain to speed up the durability test. So far so good.
The soya oil is 1/12th the cost of Tung oil, so here’s hoping that the oil eventually hardens.
The soya oil boards left out exposed to sun and rain did dry. About a month or two into the experiment they no longer felt sticky. Result.
Like the tung oil applied boards the char does not rub off. So I have tung oil applied, soya oil applied, and untreated boards — all now up on the chalet. The treated boards have been used for door and window trim. The untreated boards are being used as siding.
I will report back next year about how the various treatments fare. Should that be: compare where on the lair the wear remains fair?