Yakisugi (grilled cedar) 焼き杉 - Charring Wood as a Finishing Modality

This method has come up in several post as a method for treating wood, with the ensuing questions that follow. Shou-sugi-ban, probably better know as Yakisugi (grilled cedar) 焼き杉 is an awesome finishing effect for wood to extend its lifespan, and to beautify the wood. For method...experimentation is always my first suggestion, as your wood and available tools may vary. Otherwise, one way to do it well for a novice, is to use a "wood fire retardant" that will not allow the wood to stay ignited. This material is relatively inexpensive and helps the novice with this modality of treatment not getting out of control.

My friend Steve Sass of Crestline Industries will talk to anyone about their product line of wood fire retardants.

Feel free to ask question, and share your experiences here so we can send folks to this thread in the future.

Regards,

j

Hi JC have you any pics of this effect ?
What tools would I need ? I am thinking of buying something to sterilize bee hives and wondered if the tool would have the same effect ? I notice that Oscar Perone suggests using this effect for the outside of hives as well .

David

Hi David L,

The "kanji" above leads to a photo page. As for method, you either set the board on fire with a controlled burn, or place a torch (traditional or modern) against the wood. This may well be effective for apiary housing methods.

Regards,

j

I absolutely LOVE this treatment, but I char the wood after assembly. I use locally harvested Douglas Fir that has only aged a few months, so it still has some moisture to it(20% or so). Then I use a propane weed burner that has a control valve to char the entire structure. I then sand lightly and stain with Penofin rosewood oil. I have attached a photo of the pergola and greenhouse I built last summer on the back of my house.

I did a Perone hive and used a blow torch to treat it. It's really beautiful and I don't think I'll ever use black paint again for outdoor wood projects. My husband & I did wonder about treating the siding of our house this way, but the wood is now 18 years old. Probably best done right away.

Hi Bill B,

Beautiful Job!!....................................................LOVE IT!!


Some do find it more to their liking applying 焼き杉 technique in situ, and it can be done this way. My observations, over the years, is it is easier to scorch, sand, and oil the wood when it is sitting on a tresel or saw horse, than 7' in the air or higher while standing on a ladder.

Sometimes that can't be done and you do have to do the work after installation, as you did...and a very nice job you did....

I would really like readers to also notice that this finish does not have to be completely "blacked out," as the level of burn can be adjusted to individual tastes, before oiling.

Hi CJ,

Age has little effect on this method, so you can apply it at any time, though it is a bit more challenging to do it in place effectively (and safely)...yet it can be done as Bill has so effectively shown us.

Regards to all,

j

Love this method! I make small furniture items such as tables and shelves and this is my go to finishing method - instant, no chemical odors (smells great actually) and beautiful
Here's a small table I built using this technique:

I also found Fire safety experiments on Japanese traditional wood-based construction.

Here are a couple photos from our permaculture bed and breakfast project.
We removed and charred the original 87 year old water damaged tongue and groove ceiling, wiped it with rosewood oil and re-installed. There was significant long term damage to these boards from roof leaks, so they were grey/white before treatment.

Looks great! Any "before" photos?

Thanks, I looked through the archives and only found this.
I want to start a project thread, but as you can see from this before photo; I've got my hands full.

more pictures here... http://www.houzz.com/ideabooks/169711/thumbs/shou-sugi-ban-charred-wood-siding-burnt-wood-siding

it looks absolutely gorgeous, even if it wasn't functional. And perhaps you could get away with using cheaper species of wood that aren't as rot-resistant if you used this technique?

thought you guys might like this, a really easy wood finish, charring it, sanding it, and treating it with linseed oil, video is only one minute, be sure to check it out

Hi Jay and everyone else.

Has anyone tried this technique on cottonwood or other poplars? I've got a good bit of that on our parcel that is mature and needing to come down. I'll likely give it a try this spring, but just curious if anyone has tried it? good or bad experiences? I'd be using it for siding.

thanks

Hi Dale,

That species should be workable. I would suggest a good oiling with one or a blended mix of pine tar oil, flax oil, tung oil, etc. Do this to both sides and before charring with this species.

Regards,

j

Jay C. White Cloud wrote: ... For method...


experimentation is always my first suggestion, as your wood and available tools may vary.
Regards,

j

This.

I appled this post just based on that. Never mind that Jay is clearly a professional craftsmen.

Jay C. White Cloud wrote: I would suggest a good oiling with one or a blended mix of pine tar oil, flax oil, tung oil, etc. Do this to both sides and before charring with this species.

Interesting. What is the reasoning for oiling prior to charring? I would guess that most of the oil would burn off?

You may do it after, yet I have found that pre oiling gives a more even charr and it also draws the oil deeper into the wood it seems...

I'm going to have to try this one on the next batch of Bee Hives we do
Thanks Jay

I'll post pictures once I'm done.

I charred my Perrone hive last year. Came out nice, kind of shiny. I've bought some unpainted, unassembled conventional deeps this year and I think I'll char those too, first with an oil coating as Jay recommends.

Bill Bradbury wrote:I absolutely LOVE this treatment, but I char the wood after assembly. I use locally harvested Douglas Fir that has only aged a few months, so it still has some moisture to it(20% or so). Then I use a propane weed burner that has a control valve to char the entire structure. I then sand lightly and stain with Penofin rosewood oil. I have attached a photo of the pergola and greenhouse I built last summer on the back of my house.

This looks beautiful! I would love to do this to finish my log home but don't know if the time aspect would be practical. Approx how long are you holding the torch to each portion of wood to achieve this effect? Does this "half char" still achieve a good level of rot prevention or is it mainly for aesthetics if you don't fully char?

Hi Kris,

I hope it's o.k. me answering this along with Bill, when he gets time...

This looks beautiful! I would love to do this to finish my log home but don't know if the time aspect would be practical.

Think of it this way...either way, the logs will need to be treated in some fashion unless allowing them to go gray is the aesthetic one cares for, and even then they will need some treatment eventually. 焼き杉 is a perfect treatment and no more time consuming than any other...good or well done finishing modality.

Approx how long are you holding the torch to each portion of wood to achieve this effect?

Depends on the goal for char depth, and the type of flame employed. I can say for most it doesn't take but a few seconds to get even a light char effect.

Does this "half char" still achieve a good level of rot prevention or is it mainly for aesthetics if you don't fully char?

It is hard to say for certain and no definitive studies have been done, but some is better than none and I would still apply other treatments to the wood after ward. I have now started treating all "fresh wood" with fire suppressant wash, which helps protect the wood and keeps it from fully catching fire during the charring process. I also still like oiling the wood in some cases even if it has been charred.

Hope that helps with some of the questions.

Regards,

j

Jay C. White Cloud wrote:You may do it after, yet I have found that pre oiling gives a more even charr and it also draws the oil deeper into the wood it seems...

Jay, what kind of oil do you use for the pre-charring?

Hi Cj,

I have used a blend for the last 30 plus years from a friend of mine at Heritage Finishes which is a mix of Pine Rosin, Tung oil, Flax oil, Beeswax, and a citrus oil thinner/blender (all food grade) with a UV stabilizer added for exterior applications.

For the per charring I have began using a fire suppressing wash from:

http://www.flamestop.com/faq.html

http://crestlineprotect.com/

These my be interesting to read if they haven't been already.

https://permies.com/t/42996/Finishes/Wood-Preservatives

https://permies.com/t/24462/timber/recipes-treating-wood

https://permies.com/t/46343/woodworking/Permie-friendly-wood-preservative

Regards,

j

Hi Kris,

I use a big propane weed burner, the kind that sounds like a jet when you pull the trigger and smoothly go longitudinally down each board while a helper with heavy gloves comes in behind me to put out the small fires that start. It really goes quickly; faster than staining. Then we use a cabinet or card scraper to remove the surface char, though the pergola above was sanded with a power sander to save time. The card scraper leaves a very nice finish, as can be seen on the T&G porch ceiling, that has less surface porosity(it cuts the wood fibers instead of abrading them), so will absorb water more slowly and so better resist decay. I would not hesitate to employ this method on a log home as you have mentioned.

All Blessings,
Bill

Big thanks. We did it on all of our new beehives.

I am planning to install 1"x 6" fir boards as a temporary (1-3 years) flooring in my single-wide mobile home, and I love the dark color of this burning technique. What would I finish it with to make it durable as a floor? I've done every search I can think of and haven't come across any threads that address natural finishes for wood floors.

When I get to building my cordwood "real home", I want to be able to re-use these boards as something within the new construction (more floor? cabinetry? trim? not sure yet)

Within the next 2 weeks we will be getting the title to the new property this temporary structure sits on, so I'm hoping to get some good answers SOON! Please help...

Hi Laura,

It can be a chanllenge to navigate doing "searches" here at Permies.com but onnce you get the "nack of it," it isn't quite as challenging as it seems..

This post thread alone has many "links" to other posts (such as I am giving below) that should answer your questions.

Here are some source post from just here on Permies that I and others have provided:

Natural wood exterior finish
Note, much of these can be used "indoors" as well...

Recipes for treating wood

Brown paper floors...
Perhaps of interest??

Hope that helps, and I will do my best to expand information if needed?

Regards,

j

These are for my pole barn. Charred 3 feet up and coated with pine tar and linseed.

Thanks for the idea,Jay C. White Cloud. I'll see if I can post a photo of my first effort. I wish it didn't have any char on the bowl, but I did this with a stove burner, so I couldn't really see.

Laura Sweany wrote:I am planning to install 1"x 6" fir boards as a temporary (1-3 years) flooring in my single-wide mobile home, and I love the dark color of this burning technique. What would I finish it with to make it durable as a floor? I've done every search I can think of and haven't come across any threads that address natural finishes for wood floors.
..

You could also have a look at ebonizing the timber using vinegar and steel wool/ nails solution. I haven't tried it, but I saved this little bit of info on it. Probably not as instantly satisfying as using a blowtorch!

ebonizing timber using vinegar and steel wool solution. the reaction occurs between tannins in the wood and the iron in the solution. it can be enhanced by adding rusted nails or by swabbing the wood with a strong tea solution beforehand to increase the tannin content of the wood. The finish will depend on the tannins within the wood.
tips: use apple cider vinegar and real iron… wait a week for the solution to react. Paint on the raw wood and it should look 50% dark grey, in 10 mins it should be very dark.

Some new garden beds I've been working on.

[URL=http://s1225.photobucket.com/user/ayanami27/media/921AE8EA-B02D-4DE4-BD5C-B3282A306D31_zpsapq66p52.jpg.html
][/URL]

Hi all, I'm planning on charring cedar boards for use as siding over a rainscreen for a house project I'm working on; I'll be using a weeding torch, and will need to char appx 5000sqft of lumber. The reasoning behind my idea is to avoid the labor of oiling/painting on a periodic basis (plus I love the look); I'm hoping I don't need to even think about maintaining the siding for as long as I live in / own the place (50+ years). A few questions remain tumbling in my head:

Should I worry about charring the backs of the boards, or just the faces exposed to sunlight? (I suppose insect resistance would be the primary goal here? and maybe unnecessary as this is over a rainscreen?)

many of you mention rubbing in oil after charring--what's the idea behind this? Can I safely skip (I'm trying to limit work for myself, as this is already a big pile of lumber?

Given my motives, how much char should I put on the boards, at minimum? Blacken the surface? Get a 'gator skin' depth? Does anybody have any anecdotal evidence on longevity vis. burn level (I saw a comment that there's no hard evidence, but figure it's worth another ask)?

I'm in the Pacific NW, and while cedar isn't outrageously expensive, should I be considering another species? Til now I've stuck to cedar due to longevity concerns, but if the char would effectively protect any species, i.e. Doug Fir, perhaps I could consider a less expensive species to help my budget?

Any help you have would be greatly appreciated. I've learned a lot already from this site and its members--thank you all!

Hi Jonathan,

It sounds like you have a pretty good handle on the process and I will try to illuminate the rest.

1)

Should I worry about charring the backs of the boards, or just the faces exposed to sunlight? (I suppose insect resistance would be the primary goal here? and maybe unnecessary as this is over a rainscreen?)

I would just do the faces and sides, but it won't hurt to do all six sides.
2)

many of you mention rubbing in oil after charring--what's the idea behind this? Can I safely skip (I'm trying to limit work for myself, as this is already a big pile of lumber?

The oil is applied(I use a 4" brush) immediately after charring and sets the char. If you don't oil, the char will come off on your hands while you install them, also they will not last as long in the elements.
3)

Given my motives, how much char should I put on the boards, at minimum? Blacken the surface? Get a 'gator skin' depth? Does anybody have any anecdotal evidence on longevity vis. burn level (I saw a comment that there's no hard evidence, but figure it's worth another ask)?

When you burn wood, the volatile compounds in the wood combust first. This is what you wish to remove. So, put the burner close to the wood, but at a back angle and start slowly traveling down the board. At first the wood just deflects the flame from the burner, but when the temperature is right for this treatment, the wood will burst into flame. That means move a little down the board, maintaining that burst as you go along. The back angle will keep the burn going for a little longer and you should end up with a very black board that is lightly covered in char. Don't sand it, just oil. I love Penofin red label for the UV protection.
4) Cedar is the best.

Good Luck,
Bill

Thank you Bill.
I've been told by some that cedar is not ideal for burning--that I should consider something like fir or yellow pine instead. Any thoughts on this?
Everyone I talk to or read of seems to have their own opinion on cedar vs not and KD vs green or air dried...

Sorry Jonathan, but I've never burnt cedar as it is way to pricey here. I typically use DF and sometimes pine. I prefer to char green wood since it really case hardens, but the ceiling in my previous post is 90 year old DF and that worked just fine. Like a lot of things, there are many correct paths.

Thought I would add a couple pics of my experience.  Had a lot of fun playing with techniques. Really excited about how it came out. Also a thank you to Jay for all his help!

The wood used was air dried eastern white pine.

Hi there, I am working on an interesting (partial straw bale) eco house build in Scotland.  It will have a combination of untreated and charred larch cladding.

In regards to wood oil, I have found a lot of good information on this site but we are still confused and there seem to be a lot of expensive products out there - we are wondering:

Is there a simple, cheap and readily available oil we can use?  This is an ancient method, what would have been traditionally used?

Flax oil has been mentioned (boiled linseed oil) but it is suggested that additives are necessary.  What is the best product to use or what mix can we make ourselves that will work?

We experimented with charring a shed in situ and we brushed that with a sunflower oil and vinegar mix but I believe this may be prone to mildew?
When we touch the shed, some black comes off on our hands.  Is this to be expected when finished?

Can we just apply the oil after brushing, or is it recommended to the oil first... or run the flame over it again?

Any help would be very much appreciated!

Sye