At first we agonised over various methods full hull building. Strip planking, balsa core, foam core. Should we laminate the epoxy and glass into a female mold or over a male mold.

Building a mould or plug for a one off is a lot of work and very expensive – and we would need two – one for each hull – they are mirror opposites.

Then came the inspiration – the male mold, the plug, would form a permanent part of the hulls. And it would stiffen the outer surface. This made a lot of sense because the outer hull surface is in compression when punched by a wave,  thin laminate on a foam core can buckle – but not if it is kept straight on a ply substrate.

So we made a  plywood shell formed over stringers notched into 35 CNC cut temporary frames spaced half a metre apart. The resulting shell was very accurate, not much fairing was needed. The scarf joined ply sheets were thoroughly bonded together with triple coats of epoxy and screwed to the stringers.

After the outer ply surface was laminated with lateral, longitudinal and bi-axial layers, we rolled the hull, removed the frames and vacuum bagged a foam core to the inside surface of the ply.

Finally we laminated over the foam, again using a vacuum bag to get a thorough bond, with long, lateral and bi-axial glass.

It took only about ten weeks to build our first hull. And the temporary frames could be flipped around and used again to make the mirror opposite hull.