Boat builders are experimenting with material combinations in closed mold processing.

Boat builders around the world seem to be closing the mold, so to speak, making a move from open to closed mold processing for a variety of reasons.

“There are a lot of advantages with closed mold,” points out Leon Garoufalis, president and COO of Composites One LLC in Arlington Heights, Ill. As he puts it, vacuum infusion processing (VIP) can significantly reduce emissions compared to open mold processes, creating a cleaner working environment that makes it easier to attract workers. Plus, VIP typically allows for a higher quality of finishing. “Even with small parts you can get a high-quality finish surface on both sides,” Garoufalis explains.

Utilization of closed mold processing is a trend that has been picking up speed in recent years, across a wide range of boat styles. “Many of the very large boats are being infused and so [boat builders] are finding the quality of infusion and the type of laminates they’re getting are of a much higher quality, and they’re able to sell that quality in the marketplace,” Garoufalis says. “There’s no question there’s been a move to infusion and that has allowed suppliers to really improve their laminate structures.”

Now that closed mold processing has taken hold, boat builders are experimenting with materials more than ever, including carbon fiber and epoxy resins.

CFRP Foils Provide Stability

France-based Beneteau’s latest racing yacht is an innovative case in point, featuring a mix of CFRP and GFRP. Many racing boats feature foils that extend vertically down from the bottom of the hull and allow the boat to essentially fly above the water, gaining greater speed in the process. But on Beneteau’s Figaro 3, the addition of carbon fiber foils wasn’t meant to lift the boat out of the water. Instead, it eliminates the need for water ballast tanks otherwise used to provide stability to a boat, making the new-generation racing boat 10 percent lighter.

Achieving that balance or “righting moment” with a lighter part leads to a much more powerful boat. “It has to be very light in order to be efficient and quick,” explains Raphael Surun, composite research and development director at Groupe Beneteau.

The solo offshore racing yacht is also the first-ever production monohull boat to feature foils, according to the company. To create the foils for this monohull sailboat, Beneteau subcontracted with France-based Multiplast Groupe Carboman. “The project was an ambitious one,” commented Yann Penfornis, Multiplast general manager, in a news release. “We had to reach a lower target cost, achieve a perfect foil shape, guarantee identical weight for all parts and produce a set of foils per week over a period of one year.”