There are many ways to preserve wood, ranging from natural oils and lacquers to polyurethanes and even leaving the wood alone to age gracefully by itself.
One of the more novel ways to preserve wood while adding a unique look is called shou sugi ban. It’s an ancient wood treatment technique using fire.
What Is Shou Sugi Ban?
Shou sugi ban, or yakisugi, is a method of preserving and distressing wood by applying an open flame to it. The fire chars the wood, turning the top layer into black ash, but only lightly so. The practice originated in Japan and has been used for hundreds of years there and across the world.
The shou sugi ban process has three parts:
- Charring: The wood is treated with a low flame until it chars. Because it is difficult to treat all parts of the wood equally with the flame, certain parts of the wood will be darker than other parts.
- Cleaning: After the wood has cooled down, it is brushed and scraped to remove some of the more pronounced areas of the charring and to even out the coloration.
- Coating: The wood is treated with mineral oil, linseed oil, or other natural oils to seal in the charred wood and to offer further protection. When finished, the wood has a rich, lustrous black tone.
Tools to Use
Fire is the tool you’ll use for shou sugi ban and this fire is delivered by way of a garden torch, also called a weed torch.
A garden torch is a simple device consisting of a hose, a handle, and a wide-mouthed nozzle at the end. One end of the hose attaches to a propane tank. Its flame is low, gentle, and easy to manage.
A garden torch is used for many things around the home: burning brush and weeds, melting snow and ice, lighting charcoal, or removing paint. Since a garden torch has many uses and is relatively inexpensive, it’s usually more convenient to buy one rather than to rent one.
With shou sugi ban, there is the distinct possibility of the wood catching fire. Always do this work outside and in the open air. You should stay well away from structures or anything that can flammable.
The working surface should be concrete, brick, asphalt, or another hardscaping material that cannot catch fire. However, always have a fire extinguisher and water nearby as an additional precaution.
Do not use a butane torch. Note, too, that in the last step you will treat the wood with mineral oil, not mineral spirits—a flammable liquid similar to paint thinner.
Allow wood treated with the shou sugi ban technique to completely cool down before use.
Equipment / Tools
- Garden torch
- Propane tank
- Kitchen lighter
- Long-handled brush
- Paint brush
- Fire extinguisher
- Dust mask
- Cedar boards
- Linseed oil or mineral oil
Lay Out the Planks
Lay several of the cedar planks on the working surface side-by-side. Have the fire extinguisher and water nearby.
Light the Torch
Turn on the valve from the propane tank. Press the grip handle of the garden torch. Light the nozzle with the kitchen lighter.
Char the Wood
Wave the flame across the surface of the wood. Go lightly at first. Keeping the flame farther away from the wood produces less charring but the charring is more evenly distributed. Working slowly, a 6-foot by 6-inch board will be perfectly charred in about five minutes.
Brush Charring From the Wood
Put on the dust mask. Use the brush to wipe off the charred wood from the board. Brush in the direction of the wood grain.
Start gently when brushing the wood. With enough force, it's possible to brush away too much of the charred material. When you start gentle, you can always increase the force if needed.
Wash the Boards
Set the boards at an angle. Pour water across the faces of the boards, from top-down. This helps to cool the boards down and cleans off more of the charring.
Seal the Boards With Oil
Let the boards thoroughly dry for a day or two. Apply linseed oil or mineral oil to the charred surface of the boards with a paintbrush. Let the oil soak in before using the boards. Be careful when handling the boards because the charred material may smudge clothing or other materials.