One material that is often used when for backyard and home boat building is plywood. You can get a large variety of boat plans using the stitch and glue building method. My own company Boatplans.dk is also dedicated to developing and selling boat plans for stitch and glue plywood boats.
Plywood is thin sheets of wood glued together and each ply has the veneers going perpendicular to the next ply. As you can see on the picture there are always an uneven number of plies. This is so the surface plies have their veneers going in the same direction. This is really handy when cutting the plywood.
The properties of plywood are in many ways superior to that of wood. Since the plies are glued together the dimensional stability is really good, meaning it’s possible to join plywood with epoxy and fiberglass.
The plies are glued together and this gives the main disadvantage for plywood in a wet marine environment. If the glue is not right and the plywood not sufficient protected from water the plywood will delaminate and the structural integrity of the boat will be compromised.
But there is more to plywood than this… The next part of this series will deal with the fact that plywood can be bought both cheap and really expensive. So which grade should you choose?…
Happy boat building,
Morten Olesen, Naval Architect