There are six types of layups used in the manufacturing of Clipper canoes. These construction types are: Fiberglass, Kevlar®, Ultralight , Custom Kevlar® and Duraflex Kevlar®.
Fiberglass canoes are laminated by hand using a high-grade isothalic resin. Each Clipper canoe is reinforced in the bow and stern with a minimum of two layers of Kevlar®, providing extra strength and abrasion resistance needed in these areas of high stress. Flotation tanks are glassed-in at both ends of the canoe in all layups, and are filled with bagged foam for added flotation.
Three hull stiffening methods are used. The Escape, Scout, Cascade, Tripper, Tripper S, Packer and Solitude are stiffened with foam cross ribs. Foam ribs are resined to the hull and covered with biaxle glass roving, resulting in a light, durable canoe.
In the Yukon, Ranger and Prospector series, multiple layers of directional glass are used for hull stiffening, resulting in a slightly heavier weight than crossrib stiffening, but is less expensive and is a stronger layup. The Whitewater II, 17′ and 18′ Jensen, Sea Clipper, and the MacKenzie series come standard with a vacuum-bagged foam core.
Kevlar® is a space-aged aramid fiber which, under tension, Kevlar® fibers are 5 to 10 times stronger than an equal weight of steel. Kevlar® cloth is more expensive than fiberglass and is harder to cut and work with, hence the higher cost. Kevlar® canoes are lighter and equal to or stronger than fiberglass. A Kevlar® canoe will generally weigh 20% less than a canoe manufactured out of fiberglass.
Kevlar® canoes are built with a minimum of three layers of material (a minimum of two full layers of Kevlar®). A full layer of Kevlar® is applied to the gelcoat. Areas of high stress have additional reinforcing. Next, a layer of polyester cloth is applied. A final layer of Kevlar® completes the laminate. A special marine structural foam core is then placed to the hull bottom. An additional Kevlar® layer is then applied over the core. The Kevlar®-covered foam core produces a sandwich type construction that is extremely rigid and lightweight compared to other methods used to stiffen canoe hulls.
Ultralight Kevlar® canoes are built without any exterior gelcoat, thus the hull has the ‘honey’ color of Kevlar®. The absence of gelcoat results in a weight savings of approximately 10%. The first layer is woven S-glass which is very abrasion resistant and is stronger under compression than Kevlar®. Two layers of Kevlar® are then applied with extra reinforcement in areas of high stress.
Custom Kevlar®, our lightest layup, has a minimum of two layers of Kevlar®. The hull is stiffened with a vacuum-bagged foam core and graphite reinforced-foam ribs on the side walls. The Custom Kevlar® layup will have a clear skin coat finish and will look just like the Ultralight layup. Custom Kevlar® models will not be as durable as the Kevlar® or Ultralight constructions, but the weight of the canoe will be considerably less.
Kevlar® Duraflex is a laminate designed to be exceptionally tough. It has no foam core or ribs. The hull is stiffened by up to ten layers of structural material. A minimum of four layers are used in side walls, close to the gunnels. A highly flexible resin is used to allow the laminate to elongate under extreme force. A Kevlar® Duraflex laminate may be gelcoated but will add up to 4+ pounds. The Duraflex layups will easily outperform plastic canoe hulls of the same shape. Not only will Kevlar® Duraflex be as tough or tougher, it will also retain its shape after years of use and is also considerably lighter.
Watch the Clipper Canoes Kevlar® Duraflex “Hammer Test” video