Abstract: The invention relates to a device for obtaining, in the manufacture of a high-strength composite, an indication the reinforcement layer of the composite has been wetted throughout by the matrix material of the composite. The reinforcement layer is of the type which mainly consists of fibers or fiber bundles which do not become translucent or transparent when wetted by the matrix material, such as carbon or aramide fibers or fiber bundles. The matrix material of thermosetting plastic is applied in a liquid state in the manufacture according to, for instance, the technique of hand lay-up. The reinforcement layer includes indicating fibers which become translucent or transparent when wetted by the matrix material. A good indication is obtained if the indicating fibers have such properties that they become translucent only when the adjoining reinforcing material has been completely wetted throughout.

Abstract: A method of manufacturing boat hulls in a female mould. The hull includes a rigid reinforced plastic shell and at least one softer protective layer which is made from a plastic or rubber material and located on the outside of the shell. To provide the hull with a smoother outer surface and an improved adhesion between the shell and the layer, the layer is integrated in the hull when the hull is manufactured, by first applying the layer on the mould surface of the female mould and then building the structural shell on the layer and on free parts of the mould surface. The protective layer is accurately manufactured if it is cast moulded in a cast mould and if the female mould, or any other object that has been used when developing the female mould, is used for the cast moulding.