Historically all ships were constructed from wood. It’s a great vision to imagine Vikings and colonists crossing this world’s vast seas in vessels made without modern drills, saws, metals, or poly-adhesive materials. Material science has impacted boat building in transformational ways. We can create lighter, faster, and more durable ships today because of welding, metallurgy, epoxy resins, and fiberglass developments. Let’s look at some of the core materials used in building ships and how they work: woods, metals, and molded synthetics.
Although wood was one of the first materials used for boat construction, it is still widely used today. Wood it primarily used for smaller boats because it is easy to work with and buoyant. It is particularly a common choice for boats that range between five to seven meters, like traditional Boston Whalers. Small sailboats and dinghies are commonly made of wood by fastening planks to a frame to form the hull with a keel at the bottom ridge. The boat’s ribs or structure is often comprised of harder woods like oak, while the planking can be something softer such as cedar or pine.
The two main styles of fastening the planks to the frame are carvel and clinker. Carvel assembly places the planks together with a cotton or oakum caulking forced between them and then sealed with coats of waterproofing paints, polyurethanes, or epoxy.
Clinker planking is achieved by beveling and overlapping the wooden slats to fit together so securely that they can hold the watertight seal necessary for the hull. All wood must be sealed and refinished periodically as so to prevent rot.
Boats With A Metal Hull
Primary elements that make up the world’s biggest ships and sea tankers include rivets, welding, sheet metal, seams, and trusses. Iron, steel, and aluminum alloys are the most common metals used in the construction of ships. Various amalgams can combine different metals to emphasize specific characteristics such as creating a lighter metal, a rust-resistant material, or a more easily molded metal. Bolted or welded together, metal sheets and plates are cut to shape and fitted together to create all types of hulls from pontoon pleasure boats to global shipping vessels.
Steel hulls are sandblasted and coated with zinc and lead-based paint to ensure that they do not rust over time. Aluminum is up to 30% lighter than steel, however it is more expensive and more difficult to weld, so more skilled builders use it, and for higher-end vessels that can be stored out of the water.
Boats With Molded Synthetic Hulls
What are synthetic and molded hulls? Well, “fiberglass” is a term that everyone knows, but what is it exactly? When we were kids, some of our more artistically inclined teachers might have had us use plaster & fabric strips to make paper mache plaster sculptures with balloons or our faces. Fiberglass construction is similar, a mold or “plug” covered with strips of fabric which layered with a liquid adhesive that will freeze and harden into a shape.
Epoxy resin, and fiberglass are common in modern hull design, and they boast some impressive qualities. These modern materials have become ubiquitous in the all of the industries that need to create objects that require aerodynamic and watertight products. Speed boats, surfboards, supercars, all benefit from the extraordinary properties of fiberglass. One of the most significant factors that makes it such a useful material is reusing female moulds to construct hulls. Fiberglass is solid in tension but must be reinforced with a thin inner layer of wood or foam between the outer and inner skins to provide the strength to weight ratio necessary for the hull.
In episode 7 of Stomping Grounds, the Boat Trader crew heads to Maine for a firsthand look at the “Downeast”...