GLIMPSE INTO UNIQUE CRAFTSMANSHIP
The RESOLUTE design process has been heavily influenced by our America’s Cup yacht racing heritage combined with study of other world-class racing shell designs. We dramatically improved from those designs somewhat by making our boats slightly shorter and slightly narrower in order to reduce wetted surface and increase speed potential. We cut off excess material in the bow and stern to reduce weight. We adopted a blunt bow that pierces through waves rather than riding up and over them. Many of our competitors have now adopted this design as well.
A CLOSER LOOK: THE DIFFERENCE IS IN THE DETAILS
She is a warhorse and a boat that I would race in any regatta anywhere…Thank you for making boats that can fly.– Dan Packard; Head Coach: Commencement Bay Rowing Club
Part of what makes RESOLUTE stand above the rest is our unique approach to both design and construction. We take seriously not only what our shells look like but also how they are specially crafted. We pride ourselves on being open and honest about what goes into constructing our products and have detailed what quality materials are used to make our superior shells.
The primary materials we use are: Carbon fiber over heavier and less durable fibers, the compounding of unidirectional fibers instead of weaving, employing high grade epoxy resin and finally exclusively using Nomex™ Honeycomb for our shells’ cores.
In boat building, a fiber- resin composite usually refers to the process by which a liquid turns into a plastic. The cured resin fortifies the structure by holding the fibers in matrix, binding multiple layers of fiber together and keeping water or air from coming through the fibers.
While carbon fibers are significantly more expensive than other common fibers, such as fiberglass or Kevlar, what makes their use advantageous is their light weight, high strength and high stiffness. Due to their high modulus they are resistant to stretching, lighter than aluminum and have a greater tensile strength than steel.
The selection of the right fiber is essential in the construction of any racing shell as they are what supply strength to the final structure. When a lower-grade fiber is used—whether to lower cost or for ease of construction—the quality and integrity of the product is compromised: the final product is heavier and creates more drag; it is less durable and breaks down quicker and ultimately results in a shorter life of the boat.
There are a number of ways techniques in which fibers are adjoined: Plain weaving, twill and unidirectional.
A plain weave is where the bundles of fibers—warp and weft— go over one and under one in both directions. The advantage of having a plain weave is the ease of layup in the construction process. However, due to the nature of the weave, excess fiber that is not fully elongated and may break down over time resulting in a loss of strength.
Twill is woven fabric in which the warp and weft go over two or more bundles of fibers in both directions. Because it is characterized by ease of layup, it is often used around corners or where complex part shapes are required. Since the fibers in the weave are not fully extended, twill is also characterized as having less strength than a unidirectional layup. Over time, depending upon stresses imposed, some breakdown may be expected.
Unidirectional fibers are non-woven materials where all the fibers lay straight and flat while running in one direction. A unidirectional layup is particularly strong in the lengthwise directions of the fiber orientation as it is characterized by minimal stretch. Sometimes strength is needed in one direction and not another. Unidirectional fibers uniquely provide the ability to tailor and reinforced strength to a particular area.
One of the biggest problems with woven fibers is that the process of weaving puts kinks into the fibers. These kinks can develop microcracks in the resin over time as the structure flexes. This can easily cause the structure to get soft since the primary means of support breaks down. Conversely, unidirectional fibers lay flat and are not kinked by the weaving process. The fibers in the laminate start straight and stay straight over time. This means that the structure does not break down and get soft over time.
The importance of resin is in how it fortifies and pairs with a particular fiber so as to create a strong and resilient structure. RESOLUTE uses epoxy resin as it has the strongest physical properties of any resins in addition to resisting moisture absorption while maintaining very little shrinkage. Of all types of resin, epoxy works the best with the higher strength carbon fiber we use.
HOW WE PAIR THE FIBER-RESIN COMPOSITE:
Fibrous reinforcement material such as carbon fiber (sheet, tape, tow, fabric or mat) can be pre-impregnated with resin and are capable of storage for later use. The amount of resin pre-impregnated may be specified in order to obtain optimal strength and minimum weight characteristics. Pre-Preg parts are typically 25% lighter and 10-15% stiffer. These parts are oven cured so the resin physical properties and the heat distortion temperature are much higher. Reducing the resin content leads to greater shear strength due to better fiber-to-fiber contact in the laminate. Additionally, Prepreg laminates are less porous than those made with a wet resin process.
ADDING A CORE:
The core of the shell is sandwiched between two layers of carbon fiber. It serves to reinforce the overall structure as well as help absorb impact and prevent bending by increasing stiffness. The most widely used cores are balsa wood, foam and honeycomb. While wood and foam provide additional strength, often times when water propagates the hull, repairs become more difficult and add a considerable amount of weight. At RESOLUTE we use Nomex™ Honeycomb as it offers the same advantages as wood and foam but with a significantly less risk of damage or weight gain. Even though the material costs more than wood or foam and is more labor intensive to work we use Nomex™ Honeycomb exclusively as it results in a superior, no compromise product that protects your investment.