“Hull and deck separation is fairly common,” Crocker said. Not good. This connection between the two biggest “parts” of a boat is a critical structural feature you should look for when shopping. Skimp here and problems range from leaks into the cabin to catastrophic failure. How do better boats ensure this juncture’s integrity? I ask the builders of the boats that have yet to suffer that indignity, even after years of unsympathetic service in the test-center fleet.
Mac Privott, president of Carolina Classic, whose 25 model is a mainstay at the test center, says his boat’s hull and deck are through-bolted using locknuts, with 3M 5200 polyurethane adhesive/sealant in the lap. “And we apply fiberglass to high-stress areas,” Privott adds.
Rick Eggerding, director of product development at Tiara Yachts, is proud of the way his 3800 Open has held up at the test center. Eggerding also cites the use of tightly spaced fasteners in conjunction with Bostik 920 urethane adhesive for the boat’s high marks. Eggerding expounds deeper: “It’s like building a house — a good foundation and good walls are essential. Tiara’s bottoms are stiff; our decks are supported by bonded bulkheads. It creates a monocoque structure in which the stresses are spread around rather than being transferred directly to the sheer.”
Through-bolting and a chemical bond are also credited by Formula Boats’ plant manager, Pat Laux, in explanation of the robust longevity the pair of Formula Fastechs have shown at the test center. Formula uses Plexus adhesive. “It’s like welding the parts together,” says Laux, who describes a test process in which glued parts are placed in a hydraulic press in order to find the failure point. “We found that the glue had better adhesion than the resin and glass.”
Crocker’s a big fan of welded aluminum boats. “We can fix it a lot quicker than a crack in fiberglass and get the boat back in the water in an hour.” That’s nice to know, but so far this hasn’t been required for the 36 EagleCraft in the test-center fleet.
Welding is the way to connect a hull and deck. Steve Degel, builder of aluminum EagleCraft Boats, says some builders use rivets, but EagleCraft boats, like those that ply the secret waters year in and year out, are welded, resulting in a connection that’s super strong. “You could lift it out of the water by the deck without that joint coming apart. It’s a monocoque structure.” That word again.
“Most of the problems occur on time, ” insisted Crocker, meaning that something letting go all at once is a rare occurrence. For example, Volvo Penta’s test regimen involves diagnostic checks that might include the driver opening the engine hatch 20 times a day. Some don’t last a week, the equivalent of perhaps three years in recreational service. Others stand up fine. Hmm.
“We use full-width piano hinges instead of point-loading a strap hinge,” says Privott of Carolina Classic. “We use hydraulic lifts by Oildyne, not the cheapest pump by any means but very, very, very reliable.”
Tiara also uses pricey, top-quality parts and submits every component to rigorous testing before approval. Consider details like the way it synches its dual ram lifts so there’s no twisting of the hatch. Tiara installs hinges with through-bolts and backing pads. Just like a cleat.
At Formula, it’s more of the same: high-quality components installed in a more labor-intensive fashion. “We use so few lag screws, I wouldn’t know where to look for them in the plant,” Laux quips.
EagleCraft’s Degel has quality control locked with respect to engine-box hatches. The company fabricates its own hinges. One look at the hefty arms the hatch covers ride on is enough to tell me they’re made for the long haul.