Traditional and Classic Wooden Boat Construction Surveys
Hull Construction Methods for Survey
Maintaining the condition of a wooden boat does not require more effort than boats of other materials, but timber boats don't tolerate neglect and sustained neglect not at all.
Deterioration inevitably accumulates to a point where the cost of necessary repairs becomes prohibitive, and it may quickly exceed the market value of the boat.
Available timber boats built prior to 1970 are in the main carvel or clinker, the latter for boats less than about 30 ft . While this is testament to the method of construction it also reflects the fact these methods remained more common and are technically more straightforward to repair than other contemporaneous construction methods.
Another relevant method occasionally to be found on boats built in the decades up to about 1950 is diagonal planking. With this technique a layer of thin narrow planking was laid edge to edge at an angle, typically about 45o, to the waterlines and conventionally fastened to frames and painted with white lead. A second thicker outer layer of planking was laid edge to edge fore and aft over the inner layer to which it was fastened. A waterproofing of varnished canvas sheet was sandwiched between the layers. The thickness of the inner and outer layer in combination equals the scantling of a conventional plank.
A costly construction method in its day, it is indicative of a prestigious build and it could be expected that a very high standard of original joinery and outfitting would be found on board.
The probability of finding a hull without serious issues is low and the scope of repairs or restorations required likely to be extensive and very expensive.
Boats built by laminating several layers of constructional veneers over lofted moulds and ribbands developed in tandem with synthetic adhesives during the period following second world war. Today using modern epoxies this technique, referred to as cold moulded produces strong and comparatively light boats, though damage can be difficult to repair.
Larger hulls were built by strip planking uniform lengths of straight stock, milled with matching convex and concave top and bottom surfaces, these are bent around lofted frames or moulds, edge fastened and glued. To aid stiffness, for aesthetic purposes and where perhaps planking material of lesser durability is used the outer surfaces are covered with a lay up of mahogany veneers in the fashion of a cold moulded hull.
Marine plywood, as a material for building hulls, was popularised by chined hull designs which were produced specifically for its use and it offered many in the 1960s and 70's the opportunity for DIY builds contributing to the accessibility and affordability of sailing.