Various techniques have been adapted to burn wood, including wood-burning techniques with a torch. This special Japanese technique is known as the Shou sugi ban. In this article, we will study in detail about this wood-burning technique and how it is beneficial.
Things you will need
The ancient Japanese technique for preserving wood with fire is commonly referred to as Shou sugi ban in the West. Shou sugi ban translates to “burned cedar board” in English. The process strengthens the wood and results in a matte black finish with elegant silver streaks that resemble obsidian rock. There are a lot of benefits to this process.
- It is moisture-resistant.
- Protects against bacteria and pests.
- Lessens the risk of a fire.
- It has a deep color.(Charcoal-gray to dramatic jet black.)
- It gets a more dynamic texture.
Gather necessary supplies after you’ve prepared your work area so that you are ready with the necessities. This woodworking project requires the following materials:
- Propane torch
- Wired brush
- Sandpaper with a coarse grain
- Finishing oil
- Brush for applying oil
Technique In Detail
Step 1: Burn it
This technique can be done with smaller torches, but it is recommended to use a large propane torch. This will result in a faster and more even burn. You’ll have far more control and avoid the “splotchy” look that comes with a small torch.
It is critical to burn a few test pieces before burning your actual project wood. Boards will have varying grain patterns and moisture content. This has an impact on the burn. Notice the difference in grain pattern between the first two boards and the second two in the photos above.
The grain in the first boards is wider and longer. The burn chars much faster, and the result isn’t as nice as the second set of boards’ tighter grain pattern.
As you burn the wood, keep the torch 12-18 inches above it. You should brush on the char in that manner. There are various levels of char. A light touch is required for the stained shou sugi ban. As you burn the wood, you’ll hear it crack and pop.
Step 2: Surface preparation
When the wood has cooled, it is time to prepare it for staining. Scrape the top surface of the wood gently with a wire brush to break up the soot and ash. Gouging the wood will result in visible lines.
To remove the top layer of ash from a heavier char, use a more aggressive wire brushing technique. Wipe down the wood to remove as much soot as possible. Using an air compressor afterwards aids in the removal of any debris left behind.
Step 3: Stain it
These stains were purchased from Home Depot. Minwax has a water-based clear tint stain that can be coloured. The brochure mentions specific colors. Take care not to work in an area that is too large. It is critical to be able to remove the stain before it becomes too deeply embedded.
Brush on a coat of stain, then wipe it away after 5-10 seconds. Apply more or less stain depending on your preferences.
Step 4: Sanding and finish
Sanding with 220 grit sandpaper in areas where you want to bring out some of the natural wood looks is a technique that helps stain shou sugi ban pop. The ideal location is where the grain bends.
Sand these areas lightly to bring out the natural wood, creating a contrast of stain to char to natural. This is difficult to get wrong. Sanding can be used to bring out the grain to your liking. Just keep a light touch in mind. To finish, apply several coats of wipe-on poly. This brings out the grain and colors.
Step 5: Shou sugi ban in action
Use the well-prepared wood wherever and however you want to beautify your home or office.
What is the best approach for the best Shou sugi ban results?
Follow these shou sugi ban application tips for a long-lasting burnt wood finish that will last 50 years or more:
- Only used on softwoods. Because of its porous nature, cedar—particularly Japanese cedar—chars easily to the depth required for a protective and attractive burnt wood finish. Other softwoods, such as pine and fir, are also good candidates. Avoid hardwoods like teak and walnut because they are denser and don’t char as easily.
- Sanding is unnecessary. There is no need to sand the wood before scorching it because burning it removes any existing rough patches. If the wood has splinters or deep grooves, sand the uneven areas lightly with 150-grit or higher sandpaper.
- For maximum flame control, use propane torches. Although both propane torches and controlled fires (small, self-ignited fires on the ground) are appropriate fire sources, propane torches (e.g Red Dragon Torch on Amazon) give the average DIYer more control over where the flame hits and the intensity of the burn in that area.
The breakdown of cellulose and the formation of char occurs in wood at flame temperatures between 500 and 1,000 degrees Fahrenheit, so look for a torch that can reach at least 1,000 degrees Fahrenheit in the open air; most propane torches can reach 2,000 degrees Fahrenheit or higher.
- Set up the workspace. Because torch flames are more likely to emit gasses such as carbon monoxide into the surrounding air, shou sugi ban should only be used outside, such as in the driveway, and never inside. Similarly, avoid working on windy days because the wind can direct the flame to a nearby surface that you do not want to burn.
Place the wood plank or woodwork on a flat, level, flammable surface, such as a concrete driveway or metal worktop. Wear safety glasses and fire-resistant work gloves at all times, and keep a fire extinguisher nearby.
- To scorch small sections at a time, use a short flame. The heat and intensity of the burn are controlled by the size of the flame produced by the torch; the smaller the flame, the more intense the burn, because the hotter, dark blue inner core of the flame is closer to the wood surface; the larger the flame, the less intense the burn, because the wood is primarily exposed to the cooler, the light blue outer core of the flame. To ensure an intense burn, use the torch adjustment valve (usually a knob on the torch) to achieve a flame size of one to two inches long.
- Keep your hand steady. Slowly move the torch from one end of the surface to the other, holding the flame over each six-inch section for five to ten seconds until it blackens, then moving to the next section until the entire wood surface is blackened.
If small cracks appear on the surface of the wood at any point, use the adjustment valve to increase the flame size, which will reduce the burning intensity.
- Brush to achieve the desired color depth. Wait five to ten minutes for the wood to completely cool before gently scrubbing the entire board with a wire brush to soften the char and reveal the grain of the wood until the desired depth of color is achieved. The longer you brush, the lighter the color of the board.
- To remove excess soot and dust, use a wet cloth or an air compressor. After brushing the wood, loose soot and dust may remain on the surface; these particles make the finish appear less vibrant; remove them by wiping the wood with a wet cloth. For larger areas, rent an air compressor (available at The Home Depot), which blasts air onto the wood surface to remove soot and dust.
Finish with oil for extra durability. You can leave the charred wood bare for a rough-hewn look, or you can apply a drying oil like linseed or tung oil to give it a soft sheen and improved weather resistance.
These oils harden when exposed to air for an extended period, making the wood even more durable. For best results, reapply the oil every 10 to 15 years.
These were all the ways how you can get the best results with the Shou sugi ban. Follow the above article to know more about wood-burning techniques with a torch. It is valued not only for the protective qualities it bestows on wood but also for the striking burnt wood finish it produces, which is suitable for both rustic and modern settings. While DIYers can achieve the finish with a blowtorch, there are many pre-made shou sugi ban-treated woodworks available, ranging from coffee tables to decorative signs.