Traditional construction methods for high-performance boats use plywood egg crate and heavy glass epoxy laminate in the hull structure to provide the power, rigidity, security and ride qualities needed for speed over the water.

Thunderbird Products (Decatur, IN), a builder of Formula boats, has devised a labor-saving alternative to this type of plywood construction. Several Formula models now use a glass, and fiber and epoxy structural grid, which is bonded to the inside of the hull using ITW Plexus (Danvers, MA) fiberglass fusion adhesives.

Pat Laux, product development manager, claims the grid within the multiplane hull increases hull bottom strength by 10 percent, with no additional weight or labor.

The company chose the advanced methacrylate adhesives because they eliminate the surface preparation and priming required with urethane-based adhesives.

"We did considerable testing of the glued-in-place grid to verify the strong impact resistance, long-term fatigue-resistance and water-resistance properties of the adhesives," says Laux. "The Plexus-bonded composite grid is a substantially stronger joint and, in conjunction with the stepped hull design, results in a boat that goes 4 to 7 mph faster and rides with less pitch and more stability that a boat with conventional deep-V hull construction."

Formula also notes that the adhesives absorb impact stresses, reduce wave-induced torsional forces and produce a substantially stronger boat.

For more information on fiberglass fusion adhesives call ITW Plexus at 800-851-6692, visit