Brian Larkin knows there is a stigma attached to cold molding. It may be an unwarranted stigma, but he knows it’s out there.

The president of Maine’s Brooklin Boat Yard says people may be afraid of cold-molded boats because the construction method includes wood. Buyers think that it will be more work to maintain a cold-molded boat, and that it may even rot. That’s not true, Larkin says, but getting people to understand that remains a challenge.

“I don’t know how to overcome that perception,” Larkin says. “Buyers think cold-molded boats are a lot of work, but they are no more work than any fiberglass boat. The maintenance is the same as a fiberglass boat with the feeling of a wooden boat.”

Cold molding is a building technique that laminates multiple layers of wood veneers, or sometimes plywood, in various directions over a jig, creating a light, strong hull. Frequently, an exterior layer of fiberglass is added for abrasion resistance. The layers are bonded with epoxy, and sometimes, carbon fiber or Kevlar is incorporated for strength and weight savings. The process is called cold molding because the epoxy cures at room temperature, rather than requiring heat.

Brooklin Boat Yard has been building cold-molded boats since 1990. That first boat, a 55-footer for then-yard President Steve White, is still racing and looking good, Larkin says. It’s evidence that cold-molded boats can be incredibly durable. “We’ve built 112 boats total,” Larkin says. “Sixty of them were cold molded, and all of them are still floating, going back 33 years.”

He says some boaters don’t understand the difference between a plank-on-frame boat and a cold-molded one. In terms of durability, a cold-molded hull is more like a fiberglass hull than a traditional wooden one, he says, and cold molding has some advantages over fiberglass. It yields a hull that is lighter than same-size fiberglass boats, and it adds wood’s noise reduction, better insulating properties and looks.

“The fiberglass world has marketed themselves as no-maintenance, and everybody still has that memory of their grandfather and their wooden boat,” Larkin says. “The difference is that a traditional wooden boat can’t take the neglect. A traditional wooden boat can’t come back after eight or nine years, but a cold-molded boat can take that.”

Larkin is not the only builder who sees potential clients running for the hills as soon as they hear the word wood. Sam Temple, owner of Maine’s Rockport Marine, which has been building cold-molded boats since 1995, has run into the same issue.

“There are people who will say, ‘No, I don’t want a wooden boat,’” Temple says. “People have had a bad experience or heard a horror story that usually has to do with a traditional wooden boat being mishandled. Unfortunately, that fear sometimes carries over to cold-molded boats.”

Rockport Marine and Brooklin Boat Yard both started building traditional plank-on-frame boats in the early 1960s, but Brooklin hasn’t built a plank-on-frame boat for more than 30 years. Today, the majority of Rockport’s builds are also cold molded. Other Maine builders, including Lyman-Morse in Thomaston, Maine, regularly use cold molding to construct boats. Lyman-Morse’s two more recent builds, an express cruiser called the Hood 35 LM and a high-performance sailboat called the LM46, have cold-molded hulls.

Many Carolina builders, some of whose sportfishermen are considered among the ultimate fishing machines, use cold molding. Like the Maine builders, they say it’s hard to beat the strength-to-weight ratio of cold-molded boats, which have considerable weight savings over solid-glass boats, or even many modern cored boats.

Cold molding had its start in the 1950s, around the same time fiberglass construction began catching on. But the method didn’t take off until the 1970s, when epoxy—invented in Germany in the 1930s—became user-friendly.

Michigan’s Gougeon Brothers developed their West System epoxy resin and hardeners in the 1960s. Meade, Jan and Joel, all of Bay City, Michigan, collaborated with the nearby Dow Corporation at a time when Dow and Shell were the major base-epoxy suppliers in the United States. “The material was used mainly to replace tin in cans, and act as a protective undercoat for metal surfaces,” according to Gougeon’s website. “It created a tightly cross-linked coating resistant to water and moisture vapor.”

The Gougeons improved the stability and strength of their epoxy and made the mixing simpler and more accurate by using pumps that dispensed the resin and hardener in the correct ratios. They knew that wooden boats had relied on fasteners for thousands of years, but they realized that the fasteners were the weak point, that wood had an amazing strength-to-weight ratio, and that traditional wooden boats were built much heavier than they needed to be.

Until epoxy came around, laminating relied on resorcinol glues for adhesion. The all-wood de Havilland Mosquito bomber, a light and fast World War II plane, was built with wood and resorcinol glues, but the glues required a minimum clamping pressure of 125 psi. The Gougeons believed epoxy might eliminate the need for massive clamping pressure and could potentially bond large wooden structures efficiently and at a much lower cost.

They also knew that epoxy made a formidable moisture barrier and could be thickened and shaped to fill gaps. Using epoxy, they started building boats. By their own accounts, their first attempts were unmitigated disasters, but eventually, they built trimarans that were fast, light, strong and durable.

One of those trimarans was the 35-foot Adagio, the first large, all-epoxy bonded and sealed wooden boat built without fasteners. Launched in 1970, Adagio stunned the sailing world with her speed and strength, easily standing up to the rigors of Lake Michigan’s Mackinac Race. DIY boatbuilders quickly embraced the Gougeon’s West System. Even though fiberglass was already becoming the dominant boatbuilding material, custom boatbuilders started seeing the possibilities of building with wood and epoxy.

Adagio is still racing 53 years after she was built. Temple says customers sometimes ask how long a cold-molded boat will last. He references White Hawk, White Fin and Sophie, boats that long-time employee John England built at Renaissance Yachts in the 1980s and tells the customers he doesn’t know because “we’ve only been doing this for about 40 years.” Temple says Rockport Marine’s largest cold-molded hull, Spirit of Bermuda, which measures 82 feet on deck and was completed in 2006, is thriving “in near-constant use.”

Temple says people think it’s hard to fix damage on a cold-molded hull, but he says repairs are straightforward. Larkin agrees. “Repairs are easy,” he says. “You just step it back and you scarf it in. Just like grinding back a fiberglass boat.”

Temple says deck technology has advanced too. They can still build a traditionally constructed deck with deck beams, plywood and fiberglass, but now foam-cored sandwich construction is becoming more popular. Built on its own mold, it has a plywood layer, a foam layer blocked out for all the hardware, another layer of wood and then fiberglass or teak. “All the hardware is bedded just like any marine construction,” Temple says.

“In terms of maintenance, the cold-molded boat is like a glass boat,” Larkin says. “You paint it, and when the paint gets faded eight to 10 years later, you paint it again.”

Fiberglass construction requires a large, expensive mold, which makes it economically impracticable for building a custom one-off. Cold molding, on the other hand, is particularly useful for building one-off designs, or even when building a handful of boats, like Lyman-Morse’s Hood 35s and LM46s.

When making jigs, the stations can be cut on a CNC machine with bevels built in, a process that is extremely accurate, and which saves time and money. The hull is constructed upside down on the stations, which are mounted on a leveled floor. Stations can be temporary or permanent, which means bulkheads and frames can be incorporated into the hulls. So can transoms, inner stems, keelsons, sheer clamps, engine beds and other interior features, which makes for a stronger hull, improves accuracy, and saves more time and money.

Carolina builders tend to use plywood, whereas the Maine builders generally lean more toward planks or veneers of straight-grained woods. Temple says Rockport Marine commonly uses laminated frames of Douglas fir or African mahogany that are incorporated into the hull structure, which in essence means that the skin is glued and screwed to the male mold. Using epoxy and screws, the inner layer is attached to the outside of the frames and serves as the interior of the boat. That first layer is usually made from Alaskan cedar or Douglas fir tongue-and-groove planks, which are installed fore and aft to create an airtight skin. Temple says he prefers Douglas fir and Alaskan cedar because the woods are clear and uniform, and they bend fair.

The second layer, often Western red cedar, is then attached with epoxy and plastic staples at a 45-degree angle to the waterline and vacuum-bagged. Because of the wildfires out West, Western cedar is now harder to find, so some builders are substituting Paulownia, a fast-growing hardwood that is resistant to decay. The third layer is again vacuum-bagged and stapled at a 90-degree angle to the second layer, and the fourth layer of Douglas fir or African mahogany is glued longitudinally like the first, and again vacuum-bagged. By varying the directions of the wood, builders create omnidirectional reinforcement, which makes the hull even stronger. The plastic staples make repairs easier and, unlike metal fasteners, don’t show through the paint job.

For Rockport Marine’s R37, a recently completed 37-foot lobsterboat, Temple says the first layer was a half-inch thick, the two diagonal layers were 3/16-inch thick, and the fourth was 3/8-inch African mahogany. Two layers of 1208 fiberglass were then laid over the hull and vacuum-infused, all with West System’s epoxy.

Larkin says Brooklin Boat Yard sometimes builds a hull out of five layers. The first layer runs horizontally stem to stern, the second layer runs vertically, the next two layers run diagonally against each other, and the last layer runs horizontally.

The entire process is not inexpensive, but Temple says it’s cost-effective for one-off construction. “Where the fiberglass gets its efficiency is in reusing the mold,” he says. “The process we use can have very little temporary structure. To be able to bend that first layer over permanent structure that stays with the boat is efficient in comparison to tooling a fiberglass mold.”

Temple says having wood inside the hull still scares some people off because they think back to the days when builders used balsa or other woods for the cores inside fiberglass boats, which then sometimes delaminated. But back in those days, a plywood or balsa core would usually be wedged between two layers of fiberglass and joined with polyester resin, which didn’t adhere well to wood. In cold molding, the layers are joined with epoxy, which bonds effectively with almost any substrate, including metal, glass, masonry, wood, foams and carbon fiber, and is waterproof.

Temple and Larkin think the use of high-tech materials may be bringing more boaters around to the idea of building or buying a cold-molded boat, even though the hull may include wood.

Brooklin Boat Yard now builds its Eggemoggin 47 sailboats out of one layer of wood with carbon fiber on the inside and another layer of carbon on the outside that makes a light, strong hull that’s only a half-inch thick. “When people hear carbon, they get all excited,” Larkin says.

Temple concurs. “People understand the advantage of carbon fiber because it’s used so much these days,” he says. “When a designer wants to integrate carbon fiber in a hull structure, that can achieve a very high-performance hull. We did that on Mist, a Bill Tripp design we completed a couple of years ago. We added carbon fiber between wooden layers and had foam in the hull for further weight savings.”

Larkin says Brooklin Boat Yard is building more powerboats and fewer sailboats, which used to be their bread and butter. A few years ago, the yard built a cold-molded Wheeler 38, a replica of Ernest Hemingway’s fishing boat, Pilar. The team recently built two jetboats and a couple of center consoles. A 38-foot lobster-style boat is on the books, a 45-foot Downeaster is on the design table, and a cold-molded Wheeler 55 is under construction.

Rockport Marine is also building more powerboats. The R37 lobsterboat was commissioned by a client who previously had a smaller cold-molded powerboat built at the yard.

Temple thinks people are beginning to realize that Maine boat builders are not stuck on tradition. “I think it’s becoming apparent that we’re not shoeless guys smoking pipes up here,” he says with a laugh. “They realize we’re not these hopeless romantics, doing the same old thing, but that we can get them the performance they’re after.”  

This article was originally published in the November 2023 issue.