Skip to main content

Fiberglass Gets VIP Treatment

Few boatbuilders would go to Victoria, British Columbia, just for a plate of pizza and barbecued chicken, so the attraction on Esquimault Harbour on a recent Saturday clearly was the lure of a way to build fiberglass boats stronger, lighter and smarter.

About 80 professionals from Washington state and British Columbia found their way to the Vancouver Island city to watch a new and less messy process for assembling glass fibers and liquid resins to make a stronger and, perhaps, less costly fiberglass yacht.

The technique demonstrated at Victoria has a generic name, vacuum infusion process, which allows the use of one of the world's best known acronyms: VIP.

It is related distantly to the vacuum bagging process most fiberglass yacht makers have been using for years on some boat parts to squash together fiber and resin and to squeeze out unwanted air bubbles. More important, it is sufficiently different from a similar, but patented, infusion process called SCRIMP that VIP users need no license and pay no fees to the patent holder.

The Victoria process, which is almost as simple as sipping a soda through a straw, promises reduced labor costs, may require less material than traditional handlaid fiberglass work and, by containing toxic chemical vapors, is a winner environmentally.

A few yacht builders-including Intermarine, J Boats, San Juan Composites, Campion and Christianson-use some form of vacuum infusion, either VIP or SCRIMP. Some kayaks are fully infused, and the system has been used to produce industrial and commercial products, including windmill blades.

Despite that strong start, the process has a long way to go before you'll find it widely used in all fiberglass boats. Changeover requires modification of molds and shop equipment, training workers in the new process, and the acquisition of vacuum pumps and other gear, as well as changing the minds of builders who are happy with the methods they now use.

Vacuum infusion is no longer just a blip on the horizon, however. It holds great promise for better boats in the future for most of us. It just will take time to get there.

In an unusual gesture to help speed up getting there, a builder and naval architect experienced in VIP work and a supplier of glass fabric and resins scheduled a day of lectures and demonstrations for Northwest builders. It was held in the shops of Park Isle Marine, which is using VIP on the deckhouse and flybridge for a 65-foot displacement trawler and which plans to build a line of fully infused 37-foot pilothousestyle sailboats.

The architect is Greg Marshall of Victoria. Gordon Lacy, an architect and engineer on his staff, is one of the nation's infusion experts and supervised the construction of three 123-foot motoryachts with VIP in Savannah, Georgia. Composites One is a Canadian supplier of fiberglass and resins.

While most boatbuilders have attended seminars on construction processes, seldom has a builder invited the competition in to see just how it does its work.

Roy Parkinson, president of Park Isle Marine, heeded a recommendation by Marshall and Lacy and adopted VIP after using conventional handlaid methods to build the hull for the 65- foot trawler. With vacuum infusion, his crew has built the Portuguese bridge, deckhouse and flybridge for the oceangoing yacht, challenging work because of the complex molds needed for those structures.

"I don't see a negative, other than the learning curve," Parkinson says.

Molding Magic

The simplest way to distinguish between the two processes may be to remember that with traditional vacuum bagging, resin is applied to glass fiber by hand before the vacuum is applied. With infusion, the fabric and core are assembled "dry," and resin is applied while a vacuum is being pulled.

To keep the difference in mind, I went to the American Tug plant at LaConner, Washington, to watch the crew vacuum bag a deck panel for the saloon of a 34-foot tug yacht. It was extraordinarily simple, so simple the crew refers to it as "cave man" boatbuilding.

The panel was flat, but with a curved end. A simple wood mold was laid on a smooth table that had been waxed so nothing would stick.

Strips of fiberglass cloth were laid on the tabletop, inside the wood mold. Each overlapped its neighbor by a couple of inches. Using a low-pressure sprayer, a workman saturated the fiber with a purple resin and then used a small metal roller to flatten it and work out air bubbles and wrinkles.

Rigid Dyna Core honeycomb panels were laid on the wet fiberglass, filling the mold perfectly. Clear vinyl sheeting, the kind often used as a vapor barrier under houses, was spread over the mold and fixed in place with several runs of duct tape. A small hole was poked in the vinyl and the vacuum tube inserted, then sealed with modeling clay and more tape.

The vacuum pump was turned on and the vinyl was sucked flat onto the foam panel. After about 40 minutes, the vacuum was turned off and the vinyl sheeting peeled away. Another layer of fiberglass fabric was epoxied to the top of the honeycomb panel, but vacuum bagging was not needed.

While that part cured, I climbed aboard a boat under construction and stomped on a deck made a few days before. There was no bounce.

The composite deck is lighter than wood decks once used in fiberglass boats (it's awkward, but one man can lift the glass deck), stronger and takes less time to build.

The handlaid process demonstrated in LaConner is typical in the boating industry. Hulls, deckhouses, bridge decks and other parts of boats are made in similar fashion. Proponents argue that the personal attention of workers and the hand wetting of all fabric means there's little chance for flaws in the part being made.

Vacuum bagging is not limited to simple flat sections. Other builders, including Grand Banks, use vacuum bagging in the production of hull and deckhouse sections.

In Victoria, Lacy offered two morning seminars on the infusion process. After pizza and chicken, Park Isle Marine workers demonstrated VIP by building the roof for the first of the 37- foot Royal Passage sailboats and several flat panels for the 65-foot trawler.

The sailboat roof has rounded corners and is curved on top, making it more complex than the deck mold at American Tug.

Because it would have a painted exterior surface, a clear gel coat first was applied to the waxed surface. A fiberglass skin coat, glass fabric, an inner panel of rigid foam core and additional layers of fabric followed it. The dry components were held in place with small shots of spray adhesive.

A resin delivery system, consisting of an espalier of leaky tubes, was laid on the mold, along with a sheet of "peel coating" that would keep things from sticking together. A vacuum tube was laid around the perimeter of the mold and connected to a vacuum generator. It all was covered with the "bag," more plastic sheeting. The dry components were held under vacuum several hours to remove air and moisture.

Workers searched for bag leaks using an electronic detector and patched holes with tape.

Resin and catalyst were mixed in a clean garbage can, and the end of the suction tube was placed in the mix. The vacuum pump was switched on. Nothing much seemed to happen for a while, and the procedure was slow and quiet. A crowd of builders surrounded the form to watch.

Because of the peel coat, the mold had a greenish cast. As the resin was sucked up into the leaky tubes and began spreading through the layers of glass and foam, the color gradually darkened. It took about 15 minutes for the entire part to turn dark green, indicating that the glass fabric and foam core were saturated with resin.

The resin flow was stopped, but the vacuum pump was left on overnight to assure saturation.

Take A Deep Breath

For occasional visitors to fiberglass lamination shops, the first and most obvious benefit of vacuum infusion is in the nose. VIP eliminates most of the stink of styrene that permeates lam shops using traditional methods to lay up fiberglass. For those who work VIP full time, there is no need for respirators and protective moon suits, because toxic gases are not released into the shop atmosphere.

At American Tug, the crew molding the deck panel wore coveralls and jeans because the work was relatively clean and there were no toxic emissions. When American Tug molds a hull, however, it uses traditional handlaid techniques without vacuum bagging, and workers wear protective clothing and respirators.

The demand by U.S. and Canadian agencies for cleaner workplaces eventually may force boatbuilders toward processes such as VIP to reduce workers' exposure to harmful chemicals. It also has encouraged suppliers to develop resin formulas that generate fewer toxins.

Because VIP is a closed process, volatile organics and other airborne pollutants are trapped in the vacuum bag. Usually, the only emissions are from the vacuum pump exhaust (which can be filtered) and from open resin barrels, Lacy says.

Builders now use huge fans to ventilate lamination spaces and have filters to capture toxins, preventing their discharge into the outside air.

In a paper he wrote about VIP, Lacy sums up the other advantages:

Strength: "Without changing the reinforcement fiber or resin, strengths are typically increased by about 1.5 times over the equivalent handlaid part."

Repeatability: "The VIP part can be made with a high degree of consistency, both within the same part and from part to part. With good process control, the VIP part can be made with a constant resin ratio and a consistently low void content."

Weight reduction: "Pound for pound, the VIP part is stronger than the handlaid part. Less material can be used when achieving a given strength (or stiffness) requirement."

Cost: "VIP parts are less expensive to produce. Material costs are nearly equal, but the VIP panel requires only about half the labor of the hand-laminated sandwich panel. There is no waiting for the resin to cure, no preparation before or after the core installation and no secondary lamination. The entire manufacturing process is completed in just one step."

The Medium

To deliver the resin to every corner and into every last fiber of glass fabric, builders need a delivery system. They call it a medium.

In VIP, the medium is the foam core. Grooves are cut into the skin of the core (sometimes on both sides), and they help transmit the resin throughout the fabric and the core itself, guaranteeing saturation and a product free of air bubbles and voids.

There are other infusion systems. SCRIMP (Seeman Composites Resin Infusion Molding Process) was developed by Bill Seeman in the late 1980s. The patented infusion process uses a fiberglass screen//like that used to provide shade in nurseries//as the resin distribution medium. Patents protect that use, and any builder using SCRIMP must be licensed by TPI, which now owns the process, and pay fees for its use. The builders of J Boats, for example, are licensed by TPI, as are Hinckley (the luxury boatbuilder), Litton Industries (a defense contractor), a bus manufacturer and others using the infusion process.

To avoid licensing and having to pay fees, engineers and architects looked for other infusion media that also would be simpler than SCRIMP. In the case of VIP, they selected the foam core that is found in nearly all fiberglass production today. Cutting grooves in the foam made it a good infusion medium and one users hope will be free of patent infringement complaints by TPI.

What's Ahead

Park Isle proved it could handle VIP before inviting the world in to watch its people demonstrate it.

The curving Portuguese bridge on the big trawler was a real test. Normally, it would be handlaid in one piece and the doors cut out later. Park Isle made the doors first, then waxed them into the bridge mold while it was infused. The result: perfect doorways with far less labor.

Some held their breath and crossed fingers when the sidewalls for the deckhouse were infused. The concern was justified: It was the largest single, continuous vacuum infusion project in Canada.

But it was successful.

And, again, the door and window cutouts were part of the mold-no one had to cut them out later.

Parkinson calculates that using VIP on the deckhouse of the 65-foot trawler reduced its topside weight by about 7,800 pounds. The savings excited the owner because it would lower the vessel's center of gravity and improve its stability at sea, Parkinson said.

Although Park Isle Marine is using VIP on that custom trawler, Parkinson believes it will be attractive to builders of production boats, too. He thinks using VIP on the planned fleet of 37-foot Royal Passage sailboats will allow the production of a superior product and give him a significant competitive edge in the marketplace.

Some production builders aren't sure labor savings will be as great as predicted. They think infusion requires the use of additional, expensive "consumables"-materials such as sheet plastic, tubing, tape, etc., that can be used only once.

Properly done, traditional handlaid procedures produce good boats, they also argue. There's no question about that.

Tom Allen of American Tug believes his shop could use VIP to manufacture the hull for the 34-footer, after modifying the mold, acquiring some new equipment and training lamination workers. He's not sure it will work well on the pilothouse deck structure because of its distinctive design, which includes a reverseraked windshield. It's a tough one, even with the handlaid system the tug-yacht builder uses.

American Tug sent three staffers to Victoria. They listened carefully and watched every detail of the demonstration but did not return home campaigning for a change in LaConner.

No doubt the use of infusion will spread throughout the industry as the benefits are more sharply identified, as procedures are explained and builders gain confidence in the product, and as pressures mount for a cleaner workplace. If it truly will deliver lower costs and a better product, marketplace competition alone may force now reluctant builders to make the switch.

Lacy and others predict that individual builders will try various procedures and develop new processes as they search for a method that best serves individual needs. Already, some builders are using vacuum infusion on a few small parts to learn the process and to assess its potential.

In any case, infusion has been around nearly as long as fiberglass. With the development of special low-viscosity resins and glass fabric, vacuum infusion is becoming a practical tool for boatbuilders.

It has been said that the boatbuilding business is among the last to benefit from technology developed by other industries. Our friends in Canada are helping to shatter that belief.

The folks in Victoria can make a pretty good pizza, too.