Process A layer of polymer film is applied over the dry fibre-core buildup and sealed over the large flanges on the edge of the mould. During resin infusion, 1 bar is pulled to draw resin through the fibreglass reinforcement and create the desired fibre-reinforced composite shape between the mould surface and film. When the entire part has been infused, the resin cures to create a highly densified and repeatable composite structure. The SCRIMP cloth and polymer film are removed after the part cures because nothing superfluous is left in the laminate. Optimum viscosity and low exotherm It took a significant amount of developmental work to identify and qualify the infusion resin. Hatteras needed optimum viscosity and open times for filling the 18.3-metre hull in one shot. They also needed to keep the exotherm low for cosmetics while retaining the required structural properties when the part cured. A dedicated team was able to do all this with the help of AOC. They took a real hands-on approach and followed every step during development. They were there for the initial hull infusions to make sure the requirements were met. To validate the end-use performance of the Hydropel vinyl ester, Hatteras went beyond the readily available data on resin coupons. Using in-house Instron equipment, the technicians built their own database of flexural, compression and tensile properties on “real world” fibre-resin laminates. After establishing resin infusion experience with the 18.3-metre hull, engineers and the work crew were ready to infuse the hull of a 21.9-metre motoryacht. The constant thickness and dimensions provided by infusion ensure a precise fit with resininfused structural components. After the infused hull shell is prepared for secondary bonding, the primary PVC foam-cored longitudinal stringers are infused into the hull. More information: www.hatterasyachts.com www.aoc-resins.com Primary PVC foam-cored longitudinal stringers are infused into the hull. * SCRIMP is a registered trademark of TPI Technology. Using a clear gelcoat allows the finished hull to be inspected after it is pulled from the mould and before an exterior marine coating is applied. A model displays the elegant lines of the new 21.9-metre motoryacht, the largest Hatteras yacht with a resin-infused hull. No35 September 2007 / JEC Composites Magazinehttp://www.hatterasyachts.com http://www.aoc-resins.com