Introduction: Shou Sugi Ban
I have been wanting to try this wood preserving method for some time now and finally got around to it. I was hired to build a new fence and sign for a dental office that matched the new paint job I did. I mentioned Shou sugi ban, showed some samples from my practice attempts and got the okay.
I did a fair amount of research including looking at an Instructable on this topic. I looked at a couple of different options on how to burn the wood, and in the end I went with a blow torch and a 30 lb. tank of propane mainly due to the fact that I can control the amount of burn on each piece of wood.
What you'll need:
Wood. Cedar works best and I just happen to have a bunch I removed from a 10 year old fence. This wood does not need to be in great shape. I'm planning on charring the wood and leaving it in place, so knots and other imperfections were no issue here.
- Propane - I used a 30 lb tank and 1,500 btu blow torch.
- Igniter - Please don't use a Bic lighter! See the Internet as to why.
- Hand-held propane torch - Just like the kind you get at your local hardware store.
- Ear protection - The torch sounds like a jet engine.
- Goggles - Do not do this without protective goggles.
- Spray bottle - Water to prevent over- burning.
- Hose - For safety and to douse the boards after burning (optional, but I found I got better results doing this).
- Fire Extinguisher - For safety and to put your neighbors at ease.
- Saw horses - I used, for lack of anything better at the time, plastic saw horses. I moved the boards as I needed to in order to burn them away from the saw horses.
- Soap - Always check your connections for bubbles when using a propane tank.
- Soft bristled brush - This type of brush fit my needs for this project. If you are using the other method of sho sugi ban where you scrape the char off of the boards, a wire brush works best.
- Linseed oil - My research indicated this to be one of the best options.
- Roller and pan - I used an old roller brush I had to apply the linseed oil.
- Gloves - Use rubber gloves and don't touch the linseed oil.
- Mask - I used a ventilator mask as the linseed oil has some gnarly fumes.
- Saw dust - To soak up wayward linseed oil.
Step 1: Choose Your Wood
Cedar works best for Shou sugi ban and I just happen to have a bunch. You can see the condition of these boards - they are 10 years old and not in the greatest condition. I used a wire brush to clean them, measured to predetermined widths, and cut all of my pieces.
Step 2: Set-up and Go!
I did this on my driveway after it had recently snowed, so I wasn't overly concerned about accidentally igniting anything that didn't have a desire to be ignited at the time. You can see in the photo the goggles, hose, fire extinguisher, soap, propane tank, torch and igniter. The torch comes with instructions on how to use it properly - please read if you lack experience and have no desire to ignite yourself.
So, put your ear protection in or on and fire that baby up, turn the input valve up half way, pull the trigger and start burning. It took me about 10 minutes per board (front and back). I moved slowly over a square foot or so at a time until I got the char I wanted then moved on. You'll get the feel for this quickly. The boards will snap, crackle, pop and smoke, but that's part of the fun. Use your water bottle to spray any hot spots.
Step 3: Brush, Water and Rest
When you've attained the desired amount of char you are looking for (burn longer for a deeper char), and after you have spritzed down any hot spots, use your soft-bristled brush to wipe away the topical dust. I did not put a lot of pressure on the brush, as I just wanted to remove any ash particles. Stand up-wind and with a huff, and a puff, BLOW those boards off and watch the black dust go flying. The more you brush, the more char you will remove. I did maybe three light-handed sweeps per area. Another reason to do this outdoors - a lot of black dust ( use your ventilator or mask).
Use your hose to water the board (lightly) on both sides. A fine mist will actually do the best here. Set your board aside in the vertical position to dry. This is an optional step, however, but these boards are thirsty at this point, and I found in my practice efforts, that the water really helped with the absorption rate of the linseed oil (didn't have to use near as much).
Step 4: Rest...Relax...Retire
Look at that beautiful char. The best part about Shou sugi ban is that this wood is now sealed for a long, long time even before you oil it. You do not need to mess with maintaining it every year. It's ready for the cat walk right now! If hail damages it, use your hand-held torch, re-char the affected area, dab some linseed oil on it and BAM! you're done.
So, now you're waiting for 24 hours before you apply your linseed oil. Rest, relax, retire for the evening as the hard part is over.
This is not hard to do, just use common sense and don't point the torch at anything you don't want to set on fire.
Step 5: Oil
After 24 hours I gather my linseed oil, hand-held torch, rubber gloves, roller and pan and my ventilator. I put a board on my saw horses, spread some old, saved saw dust beneath to absorb any over spill.
Put some linseed oil in the pan, and roll it on your board. Depending on how thirsty the board is, it could absorb either a lot or a little. I put a lot on the roller and spread it quickly. You'll see it won't stay wet for long on the wood.
Oil all sides then use your hand-held torch and go over the board lightly. This helps to burn off any excess oil.
I stood the boards vertically in my garage and let them sit for six days. I found that after that amount of time, when I brushed my hand over the board no soot or ash came off on my hand. This amount of time is personal preference, so use your own judgement on how long to let them sit. The last two photos are examples of the finished boards. Different boards and different amount of torch time will give different results.
Step 6: Finished Product
Load 'em up and head out to the job site. Be very careful transporting the boards. I put them in the back of my SUV on a towel on end just to avoid excess jostling as this will cause char to come off. But, when you char the boards this deeply, it can withstand a fair amount of char removal before you will notice anything amiss.
The first photo is a close up of the finished fence. The second photo shows it is more of a decorative fence used to define a space more than anything. The posts are 4x4 cedar posts - also recycled from a previous job. Once you Shou sugi ban them you can put them right into the ground and they will be fine. I didn't even use cement with these posts - just broken up rock and some clay. They will rot over time - but a much, much longer time than any treated lumber.
As for the sign I made for them, scroll back to the top to see it. I put just enough space between the boards for wind to get through. Boards are different widths for design purposes. The sign has already withstood 50 mph winds. I used the same materials, sunk the 4x4 cedar posts into the ground and here's a tip: take a plastic garbage bag and cut it so it is as deep as the hole is. Tack, with nails, twigs or whatever, the plastic to the inside of the walls of the hole. Pour in your concrete carefully. This is especially helpful if you cannot dig your hole to the proper depth due to roots or something else. The plastic allows the earth to heave up and down the plastic on the outside of the cement leaving the post and cement in place. An old-timer with a lot more experience than myself taught me that.
And that is Shou sugi ban. The char is a deep, dark black color which matched the black trim of the building. The char is a unique application, looks fantastic and will last for 80 years or more and won't have to be maintained. I've got a lot of ideal uses for the other type of Shou sugi ban where you scrape off the char. I'll see if I can get one of those on here before long.
Always looking for any input. Feel free to let me know of any tips or tricks you may have. Thanks for your time. I'll leave the light on for ya.