Edison’s other bright idea

Comanche, one of the flashiest examples of carbon fiber’s use. Image courtesy Billy Black/Wikipedia

By Martha Blanchfield
For Points East

Well, you could say he was, unwittingly, circling the concept of what we know today as carbon fiber. But back in the late-19th century, Edison sought to create an “all-carbon-fiber” filament of cotton and bamboo capable of burning for extended periods of time inside one of his inventions. This was U.S. Letters Patent No. 223,898 – the Edison incandescent electric lamp – soon to be known as the “light bulb.”

So, fast-forward to 1958, and high-performance carbon fibers are being created at the Union Carbide Parma Technical Center near Cleveland, Ohio. Despite the inefficient results, which yielded low strength and stiffness of properties (fibers contained around 20 percent carbon), work carried forth. Come 1963 and it is the British – namely W. Watt, L. N. Phillips and W. Johnson at the Royal Aircraft Establishment – who are first to truly realize the strength potential.

“The process was patented by the UK Ministry of Defence (sic), then licensed by the British National Research Development Corporation to three companies: Rolls-Royce, who were already making carbon fiber, plus Morganite and Courtaulds,” Wikipedia states.

Rolls-Royce introduced the material to the American market in the late-1960s via the RB-211 high-bypass turbofan engine with carbon fiber compressor blades. As for early use of carbon fiber in the manufacture of boats, Goetz Composites, of Bristol, R.I., is credited with pioneering a process that enabled crafting of the first full-carbon-fiber vessel in 1984 – Jubilation, a 54-foot German Frers design. Goetz had begun working with carbon fiber in 1977.

Boatbuilding benefits

Stronger than steel and lighter than aluminum, carbon fiber is prized by manufacturers of cars, planes, bicycles, space craft, sporting goods and more. In maritime applications, carbon fiber is used in masts (constructed using prepreg, filament winding or pultrusion techniques), hulls and ballast fins, spars and sails. Among the material’s attributes: very light in weight, high-modulus (high resistance to stretch), strength, resistance to ultra-violet rays, and a modern, high-tech look.

Carbon fiber gives greater strength at a lighter weight. It yields increased potential for speed, plus greater stability for a vessel. A sailboat with a sealed carbon-fiber mast is more capable of righting itself. Carbon fiber resists corrosion, is moisture- and heat-stable, and has super energy absorption. Its greater strength during impact also contributes to improved safety.

Todd French and Peter Webb of French & Webb, Inc., in Belfast, Maine, have extensive experience working with carbon fiber in the design and manufacture of recreational vessels. Over the years, the company has earned a reputation for pleasing aesthetics and top workmanship with their award-winning vessels. “Carbon fiber is a great material for new composite construction projects. It speaks to innovation, offering a cutting-edge design element, plus a lighter and stronger performance product,” says French, whose team has been watching its evolution and acceptance by boat owners.

“Now, with price points coming down, there is growing acceptance by a more mass audience,” he adds. “Carbon fiber is an additional tool for us.” French acknowledged that, today, carbon fiber is a desirable component. “It has its earned place – but it is not an application we use in the restoration of classic (wooden) boats.”

Carbon-fiber production

Also known as graphite fiber, carbon fiber is produced from organic polymers. The polymers consist of long strands of molecules that are bound together in microscopic crystals aligned linearly and in parallel to the long axis of the fiber. A single carbon-fiber strand has a diameter of between 0.005 and 0.010mm – finer than a strand of human hair. Approximately 90 percent of carbon fiber is made using the polyacrylonitrile (PAN) process.

Innovative Composite Engineering (ICE), a Columbia River Gorge firm based in Washington State, produces carbon-fiber sailing and marine products, including mast and boom assemblies, spinnaker poles, tiller extensions, and sail-track tubes. ICE uses the PAN method, heating strands to a very high temperature without allowing them to contact oxygen, ICE says, to prevent the fibers from burning. It is during this phase that carbonization takes place:

According to the “Unmanned Engineeria” blog (unmannedengineeriablog.wordpress.com), typical steps in a PAN process are: 1) Spinning: Polyacrylonitrile is mixed with other ingredients and spun into fibers, which are then washed and stretched; 2) Stabilizing: Chemicals are altered to stabilize bonding; 3) Carbonizing: Stabilized fibers are heated to a very high temperature for several minutes to form tightly bonded carbon crystals; 4) Treating the surface: Fiber surfaces are oxidized to enhance bonding properties; 5) Sizing: Fibers are coated to protect from damage during winding or weaving; 6) Winding: Fibers are wound onto bobbins, which are then loaded onto spinning machines; and 7) Twisting: thousands of these thin strands are twisted tightly together to form yarns of a specific size.

Carbon-fiber tow (yarn) is the thread that is woven into carbon fiber fabric. A 3K tow has 3,000 filaments; a 12k has 12,000. There is even 24k tow. Yarns may be combined with other threads or filaments to make a specific blend, or they can stay in a pure form. Carbon-fiber fabric is woven by machine into a flexible cloth which can be shaped and molded in various ways.

Carbon-fiber cloth cuts may be placed over a mold and pushed into position, then coated in a resin or plastic to form objects and/or take on shapes. Carbon fiber is also developed for use as a composite. To form a composite, heat, pressure or a vacuum binds fibers together, with the help of a plastic polymer. Combined with resins and/or epoxies, composites are used to make tubing, flooring, propeller blades, bike frames, surfboards and racing yachts.

Notable carbon-fiber boats

Comanche, the 100-foot monohull superyacht, was fashioned using pre-impregnated carbon fiber. The vessel is reportedly capable of reaching speeds approaching 32 knots.

Icon is a 65-foot sled designed by Pacific Northwest naval architect Robert Perry and built by Marten yachts of New Zealand. Her hull, rudder, mast and boom are carbon fiber. This 2001 yacht has raced the Sydney Hobart, Van Isle 360, ROLEX Big Boats San Francisco, and more. She weighs 27,000 pounds (no fuel, sails, unnecessary interior elements).

Merlin, the 68-foot design from Bill Lee, was blessed with a new taller and lighter carbon-fiber mast in preparation for the 2019 TransPac.

Then there’s the T50 Carbon Fiber Racing Sloop from Tippecanoe Boats in Washington. At 50 inches in length and more than six feet tall, these radio-controlled boats are decked out with Okoume mahogany from bow to stern. Costing less than a thousand dollars all-in, this may be one of the more affordable ways to mingle in carbon-sled-owner circles.

Carbon-fiber sails

Speaking of all-in, we cannot forget about carbon-fiber sails, which came on the scene during the 1992 America’s Cup in San Diego. Today, many grand-prix fleets embrace this fiber. And, as durability increases and maintenance and prices drop, offshore racers and cruisers are bringing more square yards onboard. Luxury and high-end cruising vessels have been sporting the cloth for some time.

Ben Sperry, president of Sperry Sails in Marion and Martha’s Vineyard, Mass., says, “Sail cloth with carbon fiber added is more durable than ever. Our clientele seeks versatile sails that are suitable for both cruising the New England coastline and participation in offshore races. As a result, the GraphX line of [carbon] laminates from Dimension Polyant is one of our most used.”

In early days, carbon-fiber sailcloth was more fragile and did require special care when handling, according to Sperry. It is acknowledged that carbon-fiber sails have low flex and give. You know that crackly, snapping sound heard as a boat turns through the eye of the wind and the headsail gets pulled into position on the new side? Well, if you take a raw carbon-fiber tow (yarn), and fold or bend it, it will snap after only one or two firm folds. Magnify that bend by the thousands of threads in cloth and you’ll comprehend the acoustics. No matter the type of sail, it’s best to avoid flogging, especially those that contain carbon fiber.

Today’s fabric vendors offer blends, weaves and fiber advances that have increased durability and performance, plus bring a great aesthetic. While, on average, the cost to purchase a sail comprised of carbon fiber is higher than that of a sail made of Dacron, nylon or liquid-crystal-polymer (LCP) Vectran, the benefits may outweigh things in the long run.

No matter the fiber content, proper care and maintenance of sails will prolong life. Sperry advises rinsing off sails that have come in contact with salt water. Also, attention should be paid to the metal bits on sails, and those that come in contact with them, in order to avoid corrosion and staining. Whether post-sail or post-season, “The best method for storing a sail is to ensure that it is thoroughly dry and nicely folded,” Sperry adds. “Avoid hard creases when flaking or folding. An annual professional cleaning is good, too.”

High-tech on classics?

Traditionalists may gasp, but high-tech filaments are finding a place on classic boats. One carpenter and rigger at the Dutch Wharf Boatyard in Branford, Conn., reveals that he’s come upon a need and a solution. “The only place I have used carbon on traditional boats is to wrap the ends of eight-stave birdsmouth spars with unidirectional tape, which I then paint. I started to do this when the butt end of the mast for my boat started to split right above the step.” Given the amount of compression a mast sees, he feels it makes sense to go the extra step to keep a birdsmouth spar from coming apart. “Although I think fiberglass would serve just as well,” he adds.

Carbon fiber is not just for yachts and other recreational vessels: Formula One race cars and wind turbine blades are crafted with it, and its unique appearance is attracting other tradesmen. Take for example the Carbon Chair from industrial designer Aeron Tozier. Recline on a platform of carbon-fiber-and-resin-coated brass, topped with leather chair cushions. Across the pond, United Kingdom-based Essence of Strength is creating carbon-composite furniture that has a gravity defying look. Company founders Kristian Arens and Clive Johnson offer sleek benches, lounges and chairs suitable for boat or boardroom.

Even everyday products are appearing with touchs of carbon fiber. How about a beer-bottle opener cut from a solid block of carbon fiber? A Baltimore, Md., area firm, Carbon Fiber Gear, sells one for $17. For the upscale navigator on a dry boat, the company also has an iPad cover made of leather that sports a touch of carbon fiber. The Londono sleeve for a 15-inch MacBook Pro is $200. This firm, and several others, also offer blades and knives accented with CF; all are sexy looking, but probably best suited for less wet environments.

Working on your own carbon-fiber project? Crafting with a solid piece of carbon fiber requires the use of a dust mask to minimize contact, especially when cutting or sanding. The fiber dust is not toxic, but it has potential to be a mild irritant to the skin, eyes and lungs, much like fiberglass. Plus, its edges can be very sharp, so gloves are expedient. Basic information about working with carbon fiber can be found on numerous websites.

So, 140 years after Thomas Alva Edison began cooking cotton and bamboo to create a strong, resilient filament for arguably his most notable invention, the electric lightbulb (he’s also credited with creating the phonograph and the motion-picture camera), where do we stand? With carbon fiber’s incredible strength-to-weight ratio, and with the promise of new composites emerging from labs in countless 21st-century industries, the future is bright for new marine-industry applications of this Space Age material.

Martha Blanchfield is a racer/writer/photographer with a keen interest in San Francisco Bay regattas. As editor and founder of the digital magazine “RenegadeSailing.com” she profiles the international waterside lifestyle and occasionally pokes fun at the loves and lives of sailors. Her photography and copy appear in “Nautique” (Netherlands publication), the “Panerai Classic Yachts Regatta” annual, “San Francisco Chronicle,” “Latitude 38,” “J/Boat” newsletter, “Points East,” “Classic Yacht,” “Adventure Sports Journal” and “Classic Boat.”

The skinny on carbon fiber sails

We’ve built many carbon-fiber sails over the last 10 years. Some of the first carbon-fiber (CF) sailcloths weren’t great. They tended to break prematurely, or the Mylar laminate didn’t hold up, but the failures were far outnumbered by the successes.

Today most of our CF sails are made of GPL cloth from a company called Dimension Polyant. This cloth is available film-on-film, with taffeta, or with their “lite skin.” The benefits of an added taffeta are better abrasion resistance, UV resistance, and general durability. Contender also offers a premium quality carbon sailcloth that’s only available in a film-on-film style. Carbon sailcloth is very light and extremely strong in terms of stretch resistance. The added taffetas and covers available will increase weight significantly, but in many cases, that added weight is worth it in terms of increased lifespan.

When sailcloth is produced it is stretched and measured in several directions before and after flutter. Carbon sailcloth is by far the best performer on every test offering extreme stretch resistance in the direction of the carbon fibers. GPL and Contender’s line of CF sailcloth are made with Technora scrim that support the off-thread line structure. This is helpful especially on larger sails where loading is not just linear loading out of the corners, but stress that comes from batten ends, slides, reefing, and general flexing and shock loading. Dimension offers a less expensive fabric called Carbon Sport which boasts the same carbon fiber on thread line, but is made with polyester scrim to support the off thread line.

Most of the CF sails we make are for cruising boats that like to race. Our CF sails are holding up really well. The longest lasting are cruising styles of cloth, which are still going after nearly 10 years. Downsides of CF include: rust when fibers are in contact with stainless steel and corrosive reactions with metal, in general. These issues can be avoided by eliminating metal fittings (using titanium rings, for instance) and generally isolating the fibers as much as possible.

We have produced sails made of laminated material for over 20 years and the new CF sails are by far the lightest, lowest stretch and most durable. The cost of materials going into a CF sail are about twice as much as polyester, so cost difference is significant, but if you’re keen to achieve top performance over time I would recommend considering CF.

Ben Sperry
Sperry Sails