In today’s boating world, a lot of noise is created around hull material. The magic word is fiberglass of course, and for good reason. It is strong, virtually maintenance free and makes boating affordable for the masses.
Fiberglass boats are not made only of fiberglass; otherwise they’d be TOO HEAVY.
But is it the miracle material that it is claimed to be? From the manufacturer’s point of view it is, because the tremendous expense of a plug and mold can be offset by the quick turnout and low labor required to produce glass hulls.
But pure fiberglass is bendy and quite heavy for its strength. The workaround to bendiness is to make the hull thicker, but that makes it heavy. The workaround for weight is to use sandwich construction (to lay a core between the fiberglass skins), but that’s expensive, both in labor and materials. A good compromise is to use plywood or balsa as a core. See how fast we come back to wood/epoxy!?
Wood/Epoxy is not wood construction, it’s COMPOSITE
Wood/Epoxy, on the contrary, embraces the best of modern and traditional boat building. It is not strictly speaking a wooden boat. It uses space-age technology to create a cored laminate protected by perfectly waterproof envelope. Epoxy has got vastly superior adhesion than either polyester or vinylester (remember the fiberglass boat’s ply-cored deck? Polyester…). The plywood shell is assembled in a matter of hours using plastic ties, fairs naturally which reduces finishing time tremendously, and takes a significant portion of the load of the structure. It is DIY-friendly, requires no mold and little or no support. Perfectly suited for one-off construction, the design is as modern as money can buy (fiberglass builders are reluctant to retire their expensive molds, so hulls are often 20 or 30 year old). And we didn’t even get into the most important aspect: Wood/Epoxy is cheaper and lighter than any other boat building method!
The most BANG for your BUCK
To compare apples with apples, let’s consider a panel from the bottom of a boat, 1ft by 1ft. This panel is required to have a certain strength and stiffness. How much, and how heavy will this panel be out of the most common boat manufacturing laminates and how do they compare with wood/Epoxy?
Chop gun is the least expensive way to make a fiberglass boat. Wet chopped glass is sprayed into a mold and rolled down after a layer of gelcoat.
Cored composite: Into a mold are laid gelcoat, outer-skin, core (balsa, plywood or foam) and inner skin.
The problem with Chop gun is that the fibers are short (±1in.) and the thickness sprayed is not precise so the strength is limited and somewhat hard to predict. The solution to these two problems is to lay it in thicker, but fiberglass is heavy, as we’ll see in a minute.
Cored laminate, on the other hand, is a good way to reduce weight; it uses a core to separate the fiberglass skins. The drawback is that it is time-consuming and therefore expensive to build. Not to mention that the core is most of the time wood of some form… So out goes the maintenance-free dream.
Now let’s go back to our bottom panel. Built out of wood/epoxy, it will cost $4.40 and will weigh 7lb. In order to meet the strength/stiffness of this panel, we’ll have to spend $5.37 (20% more) for a chop-gun laminate and this will weigh 16lb (almost 2.5x more!). A cored laminate will weigh a little less than 5lb, which is nice but it will set us back $6.93 (60% more). Oh, and did I mention that the core of that laminate is balsa wood?
Plus, a one-off construction is going to come together much quicker for a wood/epoxy boat since the panels take their shape without mold and fair naturally.
So when considering your next boat, keep in mind that using wood/epoxy is not only easy and fun to put together, it will also make a boat that performs better and will cost less to build and operate.