Shou Sugi Ban: Using Fire to Preserve Wood

Have you ever built an outdoor project and wondered what your options were for protecting it against the elements? To keep outdoor pieces looking their best, it’s important to finish them in a way that will prevent deterioration that can often occur through prolonged exposure to moisture. There is a wide variety of commercial product available, including penetrating deck finishes, spar varnish, exterior-grade polyurethane, marine varnish, and more.

Another method is called Shou Sugi Ban, a Japanese preservation method of using fire to char the wood, which is predominantly used on cedar wood.

The process of charring cedar releases a natural oil that is effective at preserving the wood and preventing water from causing harm to the wood. There are examples of cedar pieces in Japan that have been preserved for centuries using this method. In addition to its benefits as a preservative, it also adds a unique beauty to the wood.

If you’re interested in attempting the Shou Sugi Ban technique on your next outdoor project, be sure to watch our full tutorial. The basic steps include:

1. Burn the Cedar

Using a torch, thoroughly scorch the wood, reading the wood’s surface and moving at an even rate down the plank. Take caution not to burn it to the point of compromising the structural integrity. As you will see in the video, there is an appropriate depth and extent to the burning process.

2. Brush the Charred Surface

Using a stiff-bristled brush, scrape the surface of the wood until it is smooth and no longer shedding flakes of charred material.

3. Apply a Finish

Boiled linseed oil is great for cedar and will give the piece a beautiful glow while providing some additional protection against the elements.

Which project will you try the Shou Sugi Ban method on? On the exterior of a birdhouse? A pair of adirondack chairs? A bench for the garden? If you’ve tried this technique, share it with us in the Official Woodworkers Guild of America Facebook group!