What to Look for in an Older Wooden Boat
Well built wooden boats can last for decades, but all boats can and will develop problems over time. How sound any older wooden boat will be depends on many factors, including the design, the type and quality of the original timber and workmanship, and the maintenance they've received over the years. Regrettably, even the use of modern "miracle" materials doesn't guarantee btrouble freeoat. Remember that fiberglass was once thought to be mamaintenance free and no thoughts were given to the need for painting or blister repair. Similarly, although much hype has attended the development of boat building epoxies in the past 20 years, we're now learning that building a wooden boat with epoxy doesn't mean that problems can't develop. Epoxies weaken dramatically as temperature increases, and this may be a contributor to the glue failures that have been experienced with some cold-molded hulls in recent years. The answer lies not in avoiding epoxies at all cost, but in being aware of the potential for trouble, and possibly using alternatives (such as reresorcinol for some applications.
Is there a "best" construction technique? Not to my mind. If I was contemplating the purchase or construction of a wooden boat, I'd consider boats constructed using any of the techniques I've described. The type of boat would narrow the options somewhat: plywood is not suitable for round-bilge hulls, and lapstrake planking is best used on boats of about 25' and less in length. But in many ways the choice comes down to one of personal preference, and circumstance. To my mind nothing beats a well finished carvel planked hull for its feel and ,ambiance and there are more good old carvel boats to choose from than any others. On the other hand, a properly built cold-molded boat will almost certainly require less regular maintenance.
Knowing the origins of a boat -- who designed and built her -- can be valuable, in part because one of the biggest unknowns the buyer of an older boat faces is the quality of the wood that has gone into the boat. Knowing the species of wood used is important -- a boat planked with teak is less likely to develop rot than one planked with pine or mahogany -- but an inexperienced or unscrupulous builder may use an inferior grade of an otherwise excellent timber species, resulting in future problems. Buying a boat constructed by a reputable builder can help avoid such difficulties.
Keep in mind, however, that many fine wooden boats have been built by unknown craftsmen working in tiny shops and backyards. What's more, wooden boats are individual creations, and even the best set of plans is not always followed by a builder. Besides, even the best built boat may be in sad condition if not properly cared for.
The best way to evaluate a wooden boat's condition is through a thorough survey. Unless you're an expert, you'll want any boat checked out by a professional who specializes in wood, but if you look carefully, there's a lot that most boats can tell you about their condition. In addition, some features are especially desirable, while others should definitely be avoided. We'll review the construction and design details that make for a long-lived, easy-to-maintain wooden boat in a future article.
The Structure of Boats and the Nature of Wood
Boat hulls are more than just a sleekly shaped vessel whose job it is to keep the water out. Boats -- and particularly sailing craft -- have to withstand a range of loads and impacts, and builders and designers have developed some remarkably complex structures to handle those loads. The hull and deck must be strong enough to withstand loads from tons of water, and to cope with point loads, such as those that occur when a boat is propped up ashore, or hits an object as sea. Taken as a whole, the hull has to be stiff enough to resist bending forces when supported between two waves, when hard aground on a rocky ledge, and from the pull of shrouds and stays. Finally, special reinforcing must be built in to cope with loads such as those from the mast, which does its best to punch a hole through the bottom, and the rudder, which seeks to tear a hole in stern.
The problem is complicated by the fact that we expect our boats to be capable of withstanding these loads for years. The marine environment is harsh, and accelerates corrosion and decay in most materials. Boats must be designed and built with an extra factor of strength in order to cope with the inevitable deterioration that takes place over time.
The Nature of Wood
Boats can be built out of almost anything, but not all boat building materials are equally suited to the task. It is no accident that, historically, most boats have been built of wood, as it combines strength and resilience in a lightweight, easily worked form. In many respects wood is the ideal boat building material, due to its exceptional stiffness. The stiffness of a material is largely what determines how much it bends when under load. In general, if a material can resist bending or flexing, it will prove amply strong in other respects, such as resisting tensile loads. Wood combines stiffness with light weight in a way that makes it structurally more efficient -- stiffer for its weight -- than just about any other material, including high techlaminates. All wooden craft benefit from wood's remarkable structural properties, but traditionally constructed hulls can't take full advantage of the properties of wood due in part to the difficulty in effectively fastening all the various pieces together. They also absorb far more moisture than is ideal; many woods are two or even three times stronger when dry than they are when saturated with moisture. These drawbacks don't make traditional construction a poor choice; they simply mean that such craft will be somewhat heavier than a laminated hull of the same strength.
Links and other sources of information
The Gougeon Brothers on Boat Construction is available as a free download.