John Marples's Trimarans are built using what he calls a "cylinder mold". If I understand it correctly. it's an inside-out half hull form that you then vacuum-bag doorskin veneers all at once into a half-hull. Duplicated and trimmed to shape, the two halves are joined similar to stitch-n-glue. I guess it works well for narrow, deep hulls but it has its limitations. I think he has a website but have not seen it. I have a old design book somewhere that describes the process.

> Struer's web site is vague, but there are enough clues to arrive at a
> reasonable guess. They talk about pressing, molding and stretching the
> mahogany, so I believe they take thin mahogany veneers (1 mm or so) and
> laminate them over a compound-curved mold, apply an adhesive (probably
> epoxy) and then clamp the assembly with a reverse-mold top form, in a
> large veneer press. Heat may be used to accelerate the adhesive, and to
> give the wood fibers extra pliability. The result is custom-formed
> plywood, with the compound curves laminated in, that can be trimmed and
> glassed together. Given good molds, little or no fairing would be
> required.

> The next question is whether the process can be duplicated at home.
> Perhaps large-radius compound curves can be generated by vacuum-bagging
> the assembly around a full-size buck or male mold of the boat, but it
> would be very difficult to make small-radius parts like coamings or the
> little "windscreen" lip at the front of the Struer cockpit by
> that method. The veneers could be obtained from a number of sources, but
> costs would be high, and quality would be an open question. There will not
> be any time savings here for one boat, because the buck is actually a
> full-size kayak, but if the design works it can then be easily duplicated.
> For the utmost in homebuilt race boats though, it would be fun to
> experiment with this technique.