The material a kayak is made of affects its performance, durability, weight, and ease of transportation and storage, as well as the aesthetic pleasure you take from paddling it. Knowing the advantages and disadvantages of each type of material will help ensure you choose a kayak construction that best suits your needs and preferences.
So what are kayaks made of? In this article, we’ll go over the main materials used to construct hard-shell kayaks, in addition to the different manufacturing processes. Arm yourself with this knowledge before you step into a kayak shop in search of your first—or next—kayak!
How polyethylene kayaks are made
The first rotomolded polyethylene kayaks appeared in the 1970s. Plastic pellets are poured into a hollow metal mold that is then heated and rotated in a massive oven to distribute the now-molten plastic throughout the mold.
After it has cooled, the mold is removed to reveal a perfectly cast kayak that requires only light hand-finishing—outfitting the cockpit and hatches, installing skeg or rudder—to be water ready.
Polyethylene is a resilient plastic that’s used for everything from automobile body panels to food storage containers to traffic cones. As this list hints at, it is exceptionally durable and so-called “Tupperware kayaks” will last for many years with minimal care.
If the abuse your kayak may suffer includes seal launching from cobbles, dragging up sand beaches, and indelicate rooftop or trailer transportation, then polyethylene may be perfect for you. It’s also the least expensive option available.
Just because plastic can take the hits, doesn’t mean you won’t pay for it. Altercations with rocks and barnacles leave fuzzy curly-outies, increasing drag. Polyethylene is also significantly heavier than other hard-shell materials.
Polyethylene is degraded by UV, which means you should treat your plastic kayak with 303 Protectant or similar UV-blocking spray.
Mushy, speed-sapping dents, called oil-canning, occur in older, sun-damaged plastic hulls (or new ones strapped too tightly to a roof rack on a warm day).
Composite: Fiberglass, aramid, carbon fiber kayaks
How composite kayaks are made
Composite kayaks include those made from laminates of fiberglass, aramid, carbon fiber, or a blending of these and other high-tech fabrics, with some adding foam or honeycomb cores.
Gelcoat is sprayed into a separate deck and hull molds followed by hand-laid layers of cloth. Vacuum bags are applied followed by the injection of resin. Fiberglass tape and resin join the deck and the hull together.
Composite kayaks are stiff, making them fast and responsive on the water. Abrasions leave smooth scratchy-lines, which don’t affect hull speed.
Scratches, spider cracks, and even punctures can be repaired with minimal tools and a YouTube education. Composites, especially premium lay-ups like carbon and aramid, are also lighter on your shoulder but…
…not on your wallet. These are the most expensive hard-shell kayaks. The stiffness of composite also makes it the most fragile to direct hits—like surfing into a rock or flying off your roof rack.
Teal-and-purple color schemes and hopelessly outdated outfitting, both of which used kayak shoppers are likely to encounter since reasonably well cared for composite kayaks will last for decades.
How wooden kayaks are made
Most wooden kayaks are the products of do-it-yourself home builders. Wooden boat kits lend themselves to either stitch-and-glue or strip-built construction.
The former is faster and requires less woodworking skill, while the latter offers unlimited design freedom. Once assembled, the wood is typically covered in a protective layer of fiberglass, resin and varnish.
Nothing beats the natural beauty of wood. Even better, it’s among the lightest options available and is every bit as fast and—properly cared for— tough as fancy composites. Build it yourself and you’ll have a composite-quality boat at a polyethylene price.
Not handy with clamps or epoxy? Get someone else to build your wooden kayak for you, and it will cost even more than a composite boat.
No two wooden boats are ever alike. If you don’t like the craftsman’s ship, blame the craftsman!
How thermoform kayaks are made
The thermoforming process uses a vacuum to suck heated plastic sheets over a mold. The sheet material is comprised of impact-resistant ABS plastic bonded to a thin outer cap of glossy acrylic.
The two plastics produce finer edges and more complex shapes while using less material than rotomolding. Deck and hull are thermoformed separately, then joined at the sheerline with adhesive and tape.
Thermoform kayaks combine the affordability and tough, bouncy durability of plastic with the lighter weight, shiny looks and sleek feel of composites. Because manufacturing is less labor-intensive than composite construction, thermoform kayaks are priced only slightly above rotomolded.
Thermoformed plastic tends to be more flexible than composite so, while it looks the same at first glance, it may not be quite as quick in the water.
While the outer acrylic surface of a thermoformed kayak is harder and more scratch-resistant than polyethylene, even well cared for ABS degrades over a long period of time.
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All the pretty things stacked in a row. Feature Photo: flickr.com/YutakaSeki