By Capt. Bill Pike
Several years ago, resin infusion entailed a number of steps. The outer skin (including gelcoat and skin coat) was infused, with coring materials and the inner skin to follow. Not only was this time-consuming, inefficient, and prone to expensive error, it also meant that a hull, deck, or other large molding was fraught with secondary-bonding problems arising from contamination, atmospheric issues, and comparative internal weakness. However, first with a process called Resin Infused Vacuum Assisted Transfer or R.I.V.A.T. and then with a more recent and advanced methodology called Full Stack Infusion, Marlow Yachts has developed a way of infusing very large fiberglass parts in one shot, thus obviating the aforementioned problems. Today, even Marlow’s newest offering, the 97E, is constructed using the full-stack method. The process begins with fiberglass fabrics (Marlow prefers stitched materials over woven, declaring them to be ultimately stronger and more stable) numbered, labeled, and cut precisely to geometrically fit the interior of a hull, deck, or other mold. Then the fabrics are placed in their designated spots and covered with a heavy plastic film outfitted with flow media. Next, vacuum pumps remove all the air from beneath the film, sensitive equipment thoroughly checks for even minute leaks, and finally, resin is fed into the media in a very controlled fashion. What results, says Marlow, is an extremely tough, hard laminate that is totally free of voids, excess resin, and extra weight.