Written by Margaret Patricia Eaton
Wood is universally loved for its natural beauty, warmth, and inviting feel, creating a connection to nature that few other materials can match. However, wood also comes with certain inherent challenges: it can warp and become unstable, and is vulnerable to mold and insect damage. Traditionally, these issues have been addressed by applying harmful chemicals, an approach that makes the wood unsuitable for recycling, often resulting in scraps being sent to landfills.
But that was then, and this is now. Since 2008, ThermalWood Canada, a thermally modified wood manufacturer based in Bathurst, New Brunswick, on Canada’s east coast, has been offering construction customers around the globe finished hardwood products—and more recently, wood products for the music industry—all manufactured through a carefully timed process of heat and steam, with temperatures ranging between 185 and 215°C.
This process changes the physical properties of the wood and, without using chemicals harmful to the environment, creates a stable, durable, mold- and insect-resistant, environmentally friendly, and aesthetically attractive product. It is, quite literally, the wood of the future.
Back to the beginning
Robert Lennon, President and Co-owner of ThermalWood Canada, takes us back to 2005 and the day his brother-in-law, Pierre Friolet, who operated a company that did tree cutting and preparation for sawmills, “showed up on my doorstep with an armful of thermally modified wood and said, ‘Here’s the way of the future. This is the way we have to go.’”
Friolet had been on a mission to find new harvesting equipment for his own business, and it was purely serendipitous that he discovered this technology that had been developed in Finland for use with softwood. This, he believed, presented an exciting manufacturing and entrepreneurial opportunity in the North American wood industry, where it was virtually unknown.
At the same time, Lennon, who had enjoyed a 30-year career as an engineer at Brunswick Mines, which had just announced its closure, was facing the decision of whether to accept a position with the company on another continent, something his family did not want him to do. “As I was helping Pierre put a business plan together, doing research, and getting more involved, I was thinking this would be a good time to exit the mining world and enter the entrepreneurial world,” he says.
“The mine was scheduled to close in 2008, but it kept going for five more years and so I did both jobs; I continued in a leadership role at the mine and worked at developing our business. I didn’t take a salary as I was already being paid, and that allowed us to grow and become viable,” Lennon shares.
“This was a new technology in an old, mature market, and only a few people knew about it, so it required a lot of education. On top of that, there couldn’t have been a worse time to start a business than during the recession of 2008.”
The recession, however, forced Lennon and Friolet to change their business model, because in the beginning they were only going to offer their services for thermal modification. Wood manufacturing businesses would send ThermalWood their lumber, which would be treated and sent back for them to develop and manufacture their own product.
But when the recession started, no one in North America was ready to start developing their own products, so ThermalWood had to either close its doors or reinvent itself.
“Reinventing was more to my liking because I can’t quit once I start, so what we did was look for where the money was and where people understood the product, and that was Europe,” Lennon tells us. “That changed our target area, and because we couldn’t offer them service, we had to offer them product. So, we started to develop our own products and now we ship to countries around the world.”
The process and the product
The thermal wood treatment process as noted was first developed for softwood lumber, but because Lennon and Friolet wanted to use maple, ash, birch, and oak imported from mills in Quebec and Ontario, as well as New York, Indiana, and Pennsylvania, the equipment they purchased had to be converted, with over 200 recipes developed and tested for treating each type of hardwood. The wood, carefully stacked with a two-inch space between each layer to allow heat and steam to circulate clockwise, is loaded into the propane-heated kiln at the optimum temperature and length of time, which varies for different species.
In the process, the wood is physically changed at a molecular level, transforming the sugars such that it becomes hydrophobic and unattractive to insects and other pests. This means it does not soak up moisture from the air and is resistant to water damage, so will not warp, swell, shrink, or rot. An added benefit is an attractive, rich, and even coloration, which becomes darker the longer it is left in the kiln.
“Treating hardwood to create a stable, insect- and mold-resistant product has allowed these species to play in markets they couldn’t have played in before,” says Lennon. “They would normally be designated for furniture or interior use, but because of our process, we can take them outside.” This has resulted in a line of exterior siding and decking products, and components for outdoor furniture in addition to interior products such as flooring, wall and door panelling, furniture, and butcher block counter tops.
The company has also experimented with local underutilized species, such as tamarack and hemlock, which most sawmills do not want to cut because they are resinous and gummy. But after thermal treating, these species become as hard as steel, and when left outside in the sun for three months, weather to look like old barn wood. Customers are using it for accent walls or sliding doors for closets, but because of softwood lumber tariffs, it is only sold locally.
The company’s finished hardwood products are shipped across Canada—with distributors in Alberta and British Columbia—as well as to the United States, several European countries, and the Caribbean. European consumers appreciate the benefits of thermally treated softwood and are excited by the range of hardwood options, while the products’ termite-resistant qualities are particularly valued in the Caribbean. “Architects in Barbados took a piece of our wood and shoved it into a termite mound and the termites didn’t touch it for six months,” Lennon says.
Obsidian Ebony—creating a buzz in the music industry
In 2020, Lennon heard about difficulties musical instrument manufacturers, especially luthiers, were experiencing in sourcing good quality ebony wood for guitar fingerboards. Ebony is valued for its stability, ensuring a guitar will not go out of tune mid-performance due to humidity, but sadly the exotic African wood is becoming an endangered species. It wasn’t long before Lennon launched an R&D project to see if he could find a wood alternative for ebony, and after several years of trial and error—and building a small testing kiln—finally found a sustainable alternative, which is as hard and durable as ebony, and as dark and shiny in appearance.
Obsidian Ebony is made from torrefied maple that has been infused with resin under pressure and then cured under heat, for a much longer time than the other treated products, as the longer the time, the darker and more durable it is. “That makes a very stiff piece of wood that has the same density and colour as ebony. Moreover, we feel good about it, because it’s a sustainable product, and we could be helping to save a species that is becoming extinct.”
Obsidian Ebony has been industry-tested by luthiers including Fender and Gibson, who found it to be very workable, and guitarists who enjoyed playing instruments made with it. It’s also been favorably reviewed in such magazines as Tone Journey (April 2024) and Guitar World (September 2024), which noted the process “replaces 35 years of air drying and gives it a vintage sound.”
“We’ve soft-launched it,” Lennon explains, “and now that we have proof of concept and respect in the market, we’re preparing to take it to a commercial level.”
As that’s happening, he’s also thinking ahead to other applications for Obsidian Ebony and perhaps other exotic woods such as rosewood, and their potential for other stringed instruments—bass, violin, viola, cello—as well as bridge blanks and headstock veneer. He is also working with luthiers who are sitting on a substantial supply of lower grade ebony and treating it for them to improve its performance qualities; when that stock has been used up, he anticipates a customer for Obsidian Ebony. “It’s how you develop good customer relationships,” he says.
Bigger can be greener
ThermalWood Canada is about to roll out a three-year, multi-phase expansion plan, which will involve a 5,000-square-foot extension to its current 46,000-square-foot building, as a place to store wood. “We are also buying a smaller kiln so we can address the needs of the luthiers.” That will be followed by the acquisition of another kiln, the same size as that currently in operation. The new kilns on order are the “new generation of kilns” which will re-circulate the heat so it can be reused and brought back into the system, with no fumes escaping the building. When the new ones come in, the old one can be connected to the new system, and “we will stop losing energy to the outdoors.”
Preventing waste from entering the landfill is another issue that concerns Lennon, who is addressing it in several ways. One is by grinding up wood chips and narrow, leftover strips of solid wood and selling it in bulk as mulch. Typically, mulch blows away and has to be replaced, but this is an environmentally friendly product with no dyes or chemicals, it looks great, and since it doesn’t retain water, it releases it back into the ground in a timely fashion.
In addition, wood chips have been approved by the Canadian Food Inspection Agency and are being sold for barbecuing. Lennon is currently exploring a market for wood dust, which has high concentrations of lime and, when mixed with peat moss and topsoil, can help plants grow.
All of this is only possible because the company’s wood has not been treated with chemical preservatives. As Lennon says, “We like to be environmentally friendly, and it’s all about seeing what we can do. Our planet is going downhill; Mother Nature is changing her course because of things we have done, so if there is anything we can do now to change that course, we’re going to try. We’re just putting a little dent in it, but if everyone’s doing a little bit, then together we can make things happen.”