CHICAGO — Sea Ray Boats Inc. is considering trimming back the use of boat hulls made from fiberglass composites, an industry standard-bearer for close to 40 years, and replacing them with a thermoformed hull using an acrylic/ ABS blend.
The company, one of the world's largest producers of luxury motor yachts and sport boats, is evaluating boat hulls made with the thermoplastic compounds at its Merritt Island, Fla., research center, according to Michael Hungerford, Sea Ray's media services manager. The Knoxville, Tenn.-based boat maker believes the idea could be adopted eventually by leading boating companies.
Another large pleasure-craft producer, OMC Boat Group Inc. of Waukegan, Ill., also is looking into reducing, or even scrapping, the use of fiberglass hulls in favor of those made with thermoplastic resins, said Peter Van Lancker, OMC vice president for design and engineering.
Van Lancker said that — with the considerable research dollars currently spent on new hull materials — the shift to thermoplastic boat bodies could happen within five years.
Currently, no large-volume pleasure boats are made with acrylic/ABS hulls. However, acrylics have continued to encroach on many other parts of a vessel that were once made with either wood or thermoset composites.
If the shift occurs, it will have been made for a number of reasons. Not the least of those are concerns about the emission of volatile organic compounds, or VOCs, from fiberglass-reinforced materials and related air-quality regulations. Another problem is the labor- and time-intensive process to hand layup a fiberglass hull.
``Acrylics have worked out well on smaller parts, but we've never tried it for something this large,'' Hungerford said during a Sept. 25 interview at the International Marine Trades Exhibit and Conference in Chicago. ``But we can see the possibility of doing acrylic boat hulls, and it has some merit. We're studying it very seriously right now.''
Potentially, the acrylic/ABS blend could be used for everything from the cavernous body of a 60-foot yacht to the liner of a sporty, 18-foot runabout, he said. Sea Ray's initial test results could be completed in nine months.
OMC, a competing boat builder, also is considering other resins and processes to make thermoplastic boat hulls. Among the options are rotational molded boat bottoms or polyethylene hulls, Van Lancker said.
Some stumbling blocks remain before a thermoplastic-shell boat can hit the waves. One major obstacles is the cost of tooling, he said. The industry does not sell enough boats to justify spending the more than $1 million needed to buy tools for larger boats, Van Lancker said.
Thermoformed hulls also make it difficult to add decorative trim and other exterior parts. They would have to be hot stamped to the nonskid surface, he said.
``The hand lay-up process for composites makes it extremely low entry for any company,'' Van Lancker said. ``Anybody can do it in their back yard if they like. It doesn't take sophisticated equipment, just a lot of time. We'd like to get away from that.''
The manual process involves spraying gel-coated layers onto a boat, and can take as long as 12 hours, he said. In contrast, thermoforming can be automated and performed relatively quickly, he said.
The use of acrylics would give the hull a high-gloss cosmetic appeal and resistance to ultraviolet rays, he said. ABS acts as a structural agent to add toughness and keep the hull from shattering.
In the past three years, thermoformed acrylics have grown as decorative materials on many pleasure craft, including their application on deck hatches and entry-way doors, Hungerford said.
Yet, all-composite boats also are a booming market. Several sports and fishing-boat manufacturers, including Mastercraft Boat Co. in Vonore, Tenn., and Tuffy Boats, a division of Lake Mills, Wis.-based Fiberdome Inc., recently have converted much of their lines to composite boats.
Sea Ray, owned by leisure-products company Brunswick Corp. of Lake Forest, Ill., would like to shift almost entirely away from wood to plastics, according to Hungerford. The firm, which did about $565 million in sales last year, is headed that way, he said.
``I'd like to see a lot of our [boat parts] made from a pizza oven,'' said Hungerford, referring to thermoforming. ``It's a lot cheaper, more durable, easier to maintain and more fade-resistant than wood. We're big believers in plastics.''