One finished mold and a twin after it has been fiberglassed and painted with white exterior latex house paint. I will be glad to reply to comments an...
Go from sketch to model to fullsize solid boat hull in easy steps using my FOAMBOAT method. Wrapping fiberglass over a pre-carved foam male mold is not new, it is regularly used to make custom surfboards. What I offer is a way to shape a mold that will yield smooth, symmetrical and repeatable results for those of us who do not have a sculptor's eye and who do not want to get covered in foam shavings and dust. I developed the technique for making long, narrow solid boat hulls, but it could be adapted to make all kinds of shapes and molds for other purposes. The photo is 1-inch to the foot drawing of my first pontoon, P1, used to work out the techniqes, and it is all that is needed to create all the components for a model and, scaled up, for the 15-foot hull itself. Vary the sizes, shapes and spacings of the lines on the sketch to create hulls, or other objects, that suit the user. To see my related Instructables, click on "unclesam" just below the title above or in the INFO box to the right. On the new page that appears, repeatedly click "NEXT" to see all of them.
These are all the parts for a model of P01, the very thin plywood, from hobby shop, cut directly from the drawing, bats of foam cut large enough to enclose the wood. Though their edges are curved, all wood components are flat, all assembly joinery is at right angles and easily made that way by the square cross-secion of the foam batts, which act as gluing cleats.