Buying a Boat
Material MattersPlastic, Fiberglass, or Metal?
By Tamia Nelson
It used to be simple. If you wanted a kayak or canoe in the 1860s, you had one choicewood. (I'm taking about recreational boats, of course.) Then some clever men started crafting light canoes out of impregnated paper. Not long after that, builders in Maine got the idea of covering cedar canoes with painted canvas. Still later, an ingenious German tailor began making kayaks by stretching waterproof fabric over jointed wooden frames. And that's more or less the way things stayed until the 1940s.
Times change. Fabric-and-frame kayaks are still with us, but paper canoes are mighty hard to find. And only rich folks and hobbyists own wooden boats, canvas-covered or not. Most of today's canoes and kayaks are made from three materials: thermoplastic, fiberglass, or aluminum.
Thermoplastic boats are probably most common. They're the easiest to make, and therefore the cheapest. Build a mold, heat it up, and dump in pellets of plastic. When the pellets melt, spread the resulting goo around, then cool the mold and pull out a finished hull. Simple? Not really. Very complex, in fact. But once the mold's built, the resin formulated, and the process designed, a manufacturer can pull hulls at a furious pace. A couple of years ago, the Old Town plant in Maine was molding 200 hulls a day. Try doing that with a hammer and tacks!
Thermoplastic hulls are usually laminates in which a foam core is trapped between two plastic skins. The plastic skins can be polyethylene or vinyl, and the foam core can be acrylonitrile-butadiene-styrene (ABS) or poly. The ABS-vinyl sandwich is usually known by the shorthand designation ABS. It's strong. And it's heavy. Poly boats are usually heavier than comparable ABS boats, but they're also a bit cheaper. You pays your money and you takes your choice.
Not all thermoplastic boats have laminated hulls. Some kayaks and inexpensive canoes are made with a single plastic skin. These require an interior structural framework to keep their shape, and they don't like spending time in the sun. Unkind writers have coined the phrase "spastic plastic" to describe the sometimes loopy shape they assume after too many hours on a roof rack. That's a little too harsh, but single-thickness thermoplastic hulls do need careful handling.
What about fiberglass? First off, fiberglass is a somewhat misleading term. The Brits refer to it as glass-reinforced-plastic (GRP), and that's more accurate. A "fiberglass" hull is made by impregnating glass fabric with some sort of plastic resin. The cloth is laid in a mold before being wetted down. When the resin hardens, the resulting hull takes on whatever shape the parent mold gave it. Fiberglass boats require hand work, so they're usually more expensive than comparable thermoplastic canoes and kayaks. Sometimes they're much more expensive. But they can also be given finer lines, andwith judicious use of expensive materials like Kevlar and carbon fiberthey can be made a lot lighter than thermoplastic, with little or no loss of strength. How does a 19-pound pack canoe sound?
If thermoplastic boats are Hum-Vees, fiberglass boats are Jaguars.
The third choicefor canoes only!is aluminum. After World War II, aluminum canoes were state-of-the-art. Now they're barely hanging on. They're no cheaper than thermoplastic boats, and they're not appreciably lighter. They're noisy. And the glare from their unpainted decks can dazzle you. (They also make great reflector ovens on hot summer days. You're the main dish.) So why have they hung around? They don't wilt in the sun, for one thing, and they'll hold up better than either thermoplastic or fiberglass when subject to everyday wear and tear. Drag a loaded plastic boat up a beach. Turn it over. My, my, my . What deep scratches! Do the same thing with a "tin tank," though, and you'll be hard pressed to see the damage.
What material should you choose? If price is important, look at poly first. If you expect to wrap your boat around rocks regularly, go with ABS (poly's good, too). If you'd like to place first in your yacht club's annual regatta, you can't beat fiberglass. And if you want to have the lightest boat on the block, look at Kevlar and carbon-fiber laminates. (Most of these will have at least one layer of plain-Jim fiberglass, though. Don't be shocked.)
On the other hand, if you want a boat you can use for thirty years or morea boat to go with your 1955 Willys Jeep, sayget a tin tank. Paint it dull green. It won't be pretty, but you won't have to move it inside when the sun shines, either. It'll grow on you. 'Nuff said.
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