The Forestry Forum

General Forestry => Timber Framing/Log construction => Topic started by: w_w_w_31 on December 20, 2020, 01:45:01 PM

Title: Shou Sugi Ban for a squared dovetail log cabin
Post by: w_w_w_31 on December 20, 2020, 01:45:01 PM
What do you all think of this idea?  I am thinking about charring only the outside of the walls in order to take advantage of the preservative and fire retarding qualities of doing so.  I would brush the outside surface, and then use boiled linseed oil as the first coat to get something in the wood as a preservative, then something like Sikkens Cetol to top it off.

Trying to figure out how to keep the cabin "sealed" for warmth in the winter, I have thought about using something like a 2" gap between the logs (possibly 8"x6" or so). and also running an additional strip of wood, about 1.5"x3", between the logs with a foam strip on either side.  I would have to strategically place some screws through the logs in order to accommodate the door and window openings, probably cut out later in the process.  The additional strips between the logs would also act as backing for chinking when the time came.

dave
Title: Re: Shou Sugi Ban for a squared dovetail log cabin
Post by: flyingparks on December 23, 2020, 10:12:13 AM
Sounds cool to me.
Title: Re: Shou Sugi Ban for a squared dovetail log cabin
Post by: Coastallogger on October 08, 2021, 01:38:50 PM
Hi Dave, 

I had the exact same idea. Although I wasn't sure how it would look and if it would get too hot in the summer. 

Did you go through with it?

Would be cool to see. 
Title: Re: Shou Sugi Ban for a squared dovetail log cabin
Post by: Mainecoast on October 08, 2021, 09:42:21 PM
All of my trim is burned pine, Doug for, and cedar...I'd experiment if I was you. You can can burn almost to an alligator finish but then you can't really touch it or brush it. I pre fit all my trim, take it down and torch it. Works well. But you get covered in ash during the install. The other method I did was char it..and then wipe off the char with a red scotch pad and then oil. It's a really cool look and silvers over time. I used heritage oil when I did it. 
Title: Re: Shou Sugi Ban for a squared dovetail log cabin
Post by: Mainecoast on October 08, 2021, 09:43:19 PM
Oh and I'd use pure raw tung oil. Doesn't the boiled linseed almost mildew over time?
Title: Re: Shou Sugi Ban for a squared dovetail log cabin
Post by: mattgancz on October 09, 2021, 07:14:18 AM
I have used both tung oil and linseed oil.  Linseed oil has more of a propensity to yellow when compared with tung oil in my experience.  No reports of mildew from my end. 
Title: Re: Shou Sugi Ban for a squared dovetail log cabin
Post by: Don P on October 09, 2021, 08:23:05 AM
I started writing, hit wikipedia to fact check and their article is excellent, especially the last section on raw linseed oil, stand oil, and boiled linseed oil.
In our humid climate raw linseed on old barns and such just becomes a moldy black mess, boiled linseed oil at a minimum but it is not really ideal, at least here.
Title: Re: Shou Sugi Ban for a squared dovetail log cabin
Post by: Mainecoast on October 09, 2021, 08:27:25 AM
Thus the raw tung oil...I almost never use linseed oil. I like to cut my tung oil with turpentine. The boat builders almost always use raw tung oil.

Experiment with the brushing in burned wood. Getting the right texture is the key. And something you can replicate over and over. 

You could always use heritage natural oils they have a copper mildecide in the outdoor version I believez
Title: Re: Shou Sugi Ban for a squared dovetail log cabin
Post by: ShimodaLife on October 12, 2021, 02:44:58 AM
I did that on my TF tiny house in June. But I did the outside planks, not the frame itself. The burning was surprisingly easy and quick. The sealing went well; I used Tung oil cut with mineral spirits. 

I did two videos on it; I think this is the first one: Fire on the Mountain! Shou Sugi Ban Siding for Tiny House (S2E43) - YouTube (https://youtu.be/eTkdBEuRF0I)

Cheers,
JT
Title: Re: Shou Sugi Ban for a squared dovetail log cabin
Post by: flyingparks on October 19, 2021, 11:02:48 PM
Thanks for your videos. Watched, enjoyed, and learned.
Title: Re: Shou Sugi Ban for a squared dovetail log cabin
Post by: Joe Hillmann on October 21, 2021, 10:39:52 AM
The problem I have with methods like this is, you can find tons of partial information on it all over the web and you can find all sorts of videos of people showing how they did it.

What you don't see is people coming back 5/10/15/20 years later with any updates of how it is holding up.  For all we know it only lasted 5 years, began to rot and they ripped it off but never updated the original video talking about how good it was. 

It is also hard to find full information on the traditional way to do it.  Things like: what type of lumber, in what climate, what type of oil they used in history, what the normal maintenance on it is, do they use the entire tree or just the heartwood or just the sap wood, does it work with ground contact or does it have to be well protected.  All that information tends to be missing when I see blogs and videos of people saying how wonderful the method is.  I would think wood type makes a huge difference, white oak, cedar, locast and old growth pine  will all probably last much longer than poplar, maple, basswood, and pine sap wood.