What do you get when you combine lightweight wood, plastic laminates, petrochemical solvents and a whole lot of ethyl-this and poly-that to build a lightweight rolling box that houses a gas tank and one or more propane cylinders? A potential firebomb that can burn to the ground in 10 minutes. As RVtravel.com reported just a year ago, an estimated 20,000 RVs do so each year.
Less flammable construction materials are too expensive to use in lower-end RVs and, often, too heavy for use in applications when every pound counts. Flame retardants can be toxic, expensive, and sometimes ineffective. The best most RVers can do to protect themselves is to ensure they have good smoke and CO detectors, practice good propane procedures and be careful with space heaters and open flames, such as candles and stovetops. And, still, it seems like every week there’s another picture of an RV melted into a slag pile.
A new kind of fire retardant
Now there’s the first inkling of a possible solution. As described this past week in Science magazine, a team of researchers in Australia and China has developed a radically new kind of flame retardant that can be sprayed onto a variety of surfaces, such as rigid foam insulation, wood and steel, but which forms a ceramic skin when exposed to extreme heat. Moreover, the retardant flows when heated, squelching the flames before they can spread as it also resists heat conduction to the underlying surface.
Taking their inspiration from molten lava, which is composed of metal and oxygenated glasses, a team of researchers led by Pingan Song at the University of Southern Queensland created a mixture of several metal oxide powders that begins melting at about 660 degrees (F), forming a glasslike sheet. They then added tiny flakes of boron nitride, which flow easily and fill any gaps in the metal oxides, and topped the whole thing off with a fire-retardant polymer to glue the mixture to whatever it’s coating.
How does it work?
Dissolved in water, the resulting milky-white mixture was sprayed on various surfaces and allowed to dry, then was blasted with a butane torch for 30 seconds. In each case, Science wrote, the coating melted into a viscous liquid that covered the material in a continuous glassy sheet, forming a noncombustible layer. When heated, the coating spewed out nonflammable gases, such as carbon dioxide, further helping inhibit fire spread. The new approach, the team said, protected rigid polymer foam—widely used for insulation—better than more than a dozen commonly used retardants.
“This is very good work,” the magazine quoted David Schiraldi, a chemist at Case Western Reserve University who has developed other flame retardants. Noting that the materials used in the ceramic retardants aren’t particularly expensive or toxic, he added that widespread use of the innovative approach “could impact public safety in the long run.”
The research results were first reported Jan. 6 in Matter, an open-access science journal, under the headline: “A lava-inspired micro/nano-structured ceramifiable organic-inorganic hybrid fire-extinguishing coating.” It may take the folks who design RVs a while to absorb that mouthful, but once the implications sink in, the possibility of vastly improving RV safety should be obvious.
Andy Zipser is the author of Renting Dirt, the story of his family’s experiences owning and operating a Virginia RV park. The fascinating book, recently published, is available at many large bookstores and at Amazon.com.