The point is not how many layers you have, but to match as closely as possible the total thickness specified, and to have at least one layer going diagonally in each direction. But bigger boats and those with less-severe curves may accept layers of thicker material perhaps up to 1/4" (6mm) each. In any case, builders should stick as close to 1/8" (or 3mm) as possible. Another is that plywood usually costs less, and since most will paint the bottom or finish off with epoxy mixed with graphite for an unobtrusive charcoal tone, there is little reason to prefer solid wood veneers here. Because the tightest curves occur on the bottom forward, this is one reason why plywood may be preferred for the bottom. It depends on whether solid wood veneers or plywood (which bends easier) is used, and also with the area of the hull that is, depending on how tight the curves are. We are often asked how critical the thickness of each layer is that is, how close each should be to 1/8" net.
The second layer is then applied approximately 90-degrees to the first, with subsequent layers 90-degrees to the second, and so forth until the specified hull thickness is reached. The initial layer is installed diagonally at approximately a 45-degree angle. Usually, each layer is 1/8" nominal thickness, with the number of layers and desired total thickness specified on the plans. Otherwise, where curves are tight, (typically on the bottom at the bow) strip widths should be at least wide enough to receive a couple of fastenings into each end, or about 3". In fact, on some boats, aft areas on the bottom can be largely covered with sheet plywood as long as it conforms to the framing in this area. Widths of strips must be narrower toward the bow, but can be progressively wider toward the stern. The cold molded methods we use (often referred to as "double-diagonal" planking) consist of layers of solid wood veneers or thin plywood which has been cut into strips. Their typically "boxy" appearance will offend the discriminating eye of true classic boat lovers and may suffer some loss in value as a result. Yet even when finished natural, they turn out as poor imitations that just don't look authentic in the flesh. You may find some runabout designs that can be built from ordinary sheet plywood that may, on the surface, appear to be of "classic" type.
And such methods are well suited to the do-it-yourself builder since the skill level required is not high, and specialized equipment or woodworking techniques (such as steam bending) are not required.
So while the speed of application offered by sheet plywood may be lost, the methods we use (including the alternatives discussed later) are worth the extra time since they make possible the beautiful curves and contours builders look for in these boats. But first, an overview of our basic methods.Īlthough these boats are made over sawn frames crossed by various longitudinal members similar to conventional plywood hulls, sheet plywood cannot be used for planking since the hulls have reverse or compound curvatures to which sheet materials will not comply. However, other planking options and variations are possible as I'll discuss later. Our mahogany runabout plans are detailed for cold molded planking methods finished off (at least on the topsides) with natural wood mahogany veneers. Part of the purpose of the following article is to present still other optional ways these boats can be built. Otherwise, you can make your own veneers by resawing from thicker solid stock, or find a sawyer capable of such work.
Classic runabout plans professional#
Other sources our builders report using for veneers include professional boatbuilders building with such materials, millworks capable of veneering, and furniture manufacturers who either may sell such veneers directly or provide a cutting service. Builders should also check for material sources in such magazines as WOODENBOAT, CLASSIC BOATING, BOATBUILDER, and ANTIQUE & CLASSIC BOAT TRADER. Based on an article that first appeared in BOATBUILDER, July/August 2000Īlthough our classic mahogany runabout plans come with a resource list complied by ourselves and with feedback from our boatbuilder/customers, suppliers do come and go, and items such as planking veneers, may not be available "off-the-shelf" everywhere, let alone at the local Home Depot.
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