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Tough Stuff

Tough Stuff - Modern Bonding Materials
Tough Stuff
Stronger, more durable adhesives and resins are changing the way boats are designed and built.

By Capt. Ken Kreisler — September 2001
   
 


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Consider the primitive boater. To go travel on the water, he and his band of hunter/gatherers would search a nearby forest, fell the perfect tree, and launch it. Holding onto the stump of a snapped-off limb, they could easily let the current take them   to--well, wherever it was they went to hunt and gather. Getting back up river was another story and a problem that wouldn't be solved for millennia to come.

Then somebody got the bright idea that sitting in the log would be far more comfortable than hanging on, so our primitive boater hollowed out a primitive cockpit. With the invention of the oar quickly following, all was right with the nautical world. That is, until the design for the first two-piece boat came along.

Perhaps it was the stability an outrigger could afford or a mast to hold the skin of an animal as a sail, or the need for shelter when bad weather struck. Whatever it was, attaching it to the existing structure presented a huge problem, whose solutions included everything from lashings made of sinew to bone pegs to beeswax.

Boatbuilding has come a long way since then. Builders are now using adhesives and resins that are stronger and more resilient than ever dreamed of just a decade ago. The result is strong vessels whose bonding points are not only solid but also integral, creating a structure that is virtually one piece.

Here are a few products and procedures that are leading the way toward stronger, lighter boats. Some may have been used in the construction of your boat.

GOUGEON BROTHERS WEST SYSTEM®
Typical FRP construction involves a female mold into which a release agent is first applied, followed by gelcoat, which creates a cosmetically appealing exterior and provides a moisture barrier for the subsequent laminate. These layers are typically made up of fiberglass fabric saturated with resin. The lay-up "schedule" can include several layers of mat and woven roving and unidirectional, bi- and triaxial cloth (depending on the type of stress and the strength and stiffness required), plus perhaps a core material such as end-grain balsa or closed-cell foam. But whatever materials are used, the key to the process is the resin.

Michigan-based Gougeon Brothers has been perfecting epoxy composite construction techniques since the 1970s (FRP construction first appeared in the late 1950s) when it introduced its WEST SYSTEM® brand of epoxy resins. According to the company, they provide greater strength, less shrinkage, better moisture resistance, and better fatigue resistance than typical polyester resins. "When you look at the two, they seem similar," says Jim Watson, one of Gougeon's technical advisors. "But at the molecular level, it's a different story. That's because the cured, cross-linked molecular structure of epoxy resins when compared to polyester resins is stronger and tougher."

He goes on to say that WEST SYSTEM®'s fundamental chemistry provides superior adhesive properties to a wider variety of materials. As long as it's mixed correctly, it's forgiving and reliable.

Next page > Tough Stuff continued > Page 1, 2

This article originally appeared in the June 2003 issue of Power & Motoryacht magazine.

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