Fabrication with a mold

All production composite kayaks are made with a mold. Amateur builders can make a composite kayak with a mold as well.

Either a male or female mold can be used. Most are female molds, as this tends to be easiest. Two molds are actually required - one for the deck and one for the hull.

If making your own from a mold, the mold can be a copy of an existing kayak or can be a design of your own. Copies of existing kayaks are subject to the restrictions of copyright or patent laws. In some cases, it is possible to get permission to make a one-off copy of an existing design.

A female mold results in the kayak being made in the following order:

1. Release agent is applied to the mold.
2. Gelcoat is applied to the mold.
3. Fiberglass (carbon fiber, Kevlar or other reinforcing material) is applied. This may be presaturated with resin or epoxy.
4. Optional - more resin, core materials or reinforcing material is added to build up to the required strength or stiffness.
5. A vacuum bag is used to cover the layup.
6. Air is sucked out of the vacuum bag to allow air pressure to squeeze the composite layers together and remove excess resin.
7. The composite is allowed to cure.
8. The cured deck and hull are removed from their forms and mated with a seam finish.

A male mold requires the layers be applied in the reverse order.

Information on these construction techniques are in Boatbuilder's Manual and other sources.