Plywood has always been a favourite material for home builders. Unfortunately plywood has not always enjoyed a good reputation. Poor quality vessels have been launched by builders who did not have a good understanding of required techniques, or chose to ignore them. At the same time, however, many fine vessels have been built to high standards, with excellent results.

     The increased availability of good grade epoxies has made this all possible. Epoxies have further enhanced the reliability of plywood-constructed vessels to a level that they can now compete in weight and strength with aluminium and fiberglass building methods. The Gougeon brothers' wood epoxy saturation technique (W.E.S.T.) has advanced the use of laminated wood structures to a point where yacht hulls can be built far lighter and stronger than was previously thought possible using any other materials. By using composite construction involving the use of fiberglass cloth, epoxy resin, thickeners and fillers it is possible for home builders to produce high quality, light, strong plywood hulls, at very reasonable cost. The use of plywood rather than multiple layers of veneers reduces labour time drastically.

     Today's plywood is manufactured to high standards. Grading and testing is rigorous and a uniform program of inspection is followed within the industry. Only those companies consistently meeting all the requirements of this program are licensed to use the registration certification mark on their products. Failure to meet the established standards of quality results in de-certification. Quality control tests include boiling for 4 hours, drying for 20 hours at 140 - 150 degrees F, and then boiling for 4 hours to check for good glue bond.

     Many major design competitions have been won by plywood boats, with the majority of designs for home building submitted in plywood. The numerous plies give high multi-directional strength and help make the plywood stable by neutralizing dimensional changes. At the same time large panels reduce labour time over cold molding. New methods of development for multi-chine hulls produce rounded chines with section shapes very similar to the I.O.R. racers. Research done by my company, Bray Yacht Design And Research Ltd., has lead to the development of a plywood system called the New Epoxy Wood System (N.E.W.S.) suitable for home building or limited production and one off building. In most cases the hull is built on 1/2" plywood frames, spaced 3'-6" apart. 1"x 2" battens are secured to each frame between chines. Berths and settees form two box spars, port and starboard, and tie in with the bulkheads to form a very rigid egg-crate type of construction that is spacious and functional. Two layers of 6 oz. fiberglass cloth cover all exterior surfaces for a low maintenance fiberglass finish. 24 oz. woven roving is used inside and out on the chines to tie the boat together. There is no planing of chine logs etc., and although joints should be well made, epoxy will bond effectively over large gaps. Fiberglass cloth is used for bonding in all bulkheads. This is an extremely easy system, which has been used very successfully for many, many years on plywood trimarans and racing dinghies, with excellent results. Materials are readily available and a minimum of power tools are required. Epoxy resin is used for both sealing the wood and laminating the fiberglass cloth. This prevents rot, increases the strength of the wood, and gives a superior bond. The use of fir and other soft wood plywood gives a light weight skin with good strength-to-weight properties.

     This construction system opens up the option to home build your own vessel with a minimum of complication. As long as good work practices are used, and all manufacturer’s directions followed, a well-built yacht will be the end result, ready for your enjoyment on the water.