North American Marine Adhesives, Sealants and Tapes: Supply Base and Application Map

The marine adhesives market is a small market that runs on a handful of iconic part numbers. Ask anyone who has rigged a boat what goes under a cleat and the answer is 3M 5200 or 4200. Ask a production engineer what holds the deck on and the answer is Plexus. Ask a yard what goes under a portlight and the answer is Sikaflex 291 or a silicone. Those names are the market. The chemistry behind them is polyurethane, methacrylate, silicone, and epoxy, and it is not exotic. What is unusual is how completely a few products own their applications and how little a builder gains by changing.

North American recreational boatbuilding produces roughly 250,000 powerboats in a good year and closer to 180,000 in a soft one, plus a few thousand sailboats. Fiberglass outboard boats, sterndrive and inboard runabouts, and aluminum and pontoon boats each buy adhesives differently. A 24-foot fiberglass center console carries a methacrylate hull-to-deck joint, a methacrylate-bonded stringer grid and transom, several dozen bedded fittings, a bonded or framed windshield, a cast vinyl boot stripe, and a harness full of adhesive-lined heat shrink. A pontoon carries almost none of the structural adhesive but more carpet and flooring adhesive, upholstery adhesive, and butyl than any other boat type. An aluminum fishing boat carries sealant and tape and little else.

The structural adhesive volume is concentrated. Brunswick, Malibu, MasterCraft, Correct Craft, Polaris Marine, White River Marine Group, and Groupe Beneteau North America build most of the fiberglass boats and most of the pontoons in the country, and each buys methacrylate by the drum through a supply agreement with ITW Plexus or through Composites One. The bedding sealant volume is spread across every builder, every dealer, every yard, and every owner, and it flows through marine distribution rather than through the composites channel.

Geography follows the boatbuilders. Fiberglass production clusters in Tennessee, Florida, the Carolinas, and the Upper Midwest. Pontoons are built in northern Indiana and Michigan, and their furniture, canvas, and flooring suppliers sit within an hour of the plants. The glazing and canvas Tier 1s cluster near the same plants. The sealant and epoxy distributors follow the yards and the water: Seattle, Bristol, Fort Lauderdale, Annapolis.

The tiers do less work here than in any automotive lens, and the reason is that the boatbuilder applies nearly all of the adhesive itself. The hull-to-deck joint is bonded on the OEM floor. The stringer grid is bonded on the OEM floor. The transom, the bulkheads, the liner, and every fitting on the deck are bonded and bedded on the OEM floor. The composites report explains why marine has no real Tier 1 for laminate; the same logic holds for the adhesive that goes between the laminates.

What Tier 1 means in this lens is the component fabricator that bonds something before it reaches the boat. Taylor Made bonds glass into windshield frames and, on frameless and hardtop-enclosure designs, bonds the glass directly. The canvas shops seam and bond clear vinyl into acrylic canvas. The pontoon furniture and upholstery shops laminate vinyl to foam to base. The flooring supplier laminates woven vinyl and carpet to deck panels. Those five or six companies, plus the systems suppliers whose modules arrive sealed, are the whole of Tier 1, and none of them is large.

Tier 2 is where the market lives, and it splits in two. The structural half is ITW Plexus and, at the margins, the epoxy houses: Gougeon Brothers with WEST SYSTEM and PRO-SET, System Three, and Huntsman. Plexus sells to the large builders on supply agreements, with technical service and meter-mix dispensing support, and to everyone else through Composites One. The sealant, tape, and film half is 3M, Sika, Henkel, Bostik, and Avery Dennison, and it sells through marine distribution rather than composites distribution. A boatbuilder buys 5200 from the same wholesaler that sells it cleats, and often on the same purchase order.

Tier 3 is the chemistry the formulators buy: Dow, BASF, and Covestro for the isocyanates and polyols under every polyurethane sealant and hot melt, Dow and Momentive for the silicone polymers, BASF for the acrylic monomers under the PSAs and the methacrylates. None of them sells to a boatbuilder.

Distribution is the odd part. Composites One carries Plexus and the epoxy lines on the same truck as resin, glass, and core, and is the route to market for every builder that does not have a direct Plexus agreement. The marine wholesalers, Fisheries Supply, West Marine Pro, Jamestown Distributors, Donovan Marine, Land N Sea, carry 3M, Sika, Loctite, Bostik, and WEST SYSTEM alongside hardware and electrical, and are the route for sealants, tapes, and epoxy to the smaller builders, the yards, and the canvas and upholstery shops. A supplier that wants both halves of the market needs both channels.

Sixteen OEM sourcing organizations buy in this lens, the same sixteen the composites report carries. They fall into three buying patterns that have little to do with size.

The fiberglass production builders, Brunswick (Sea Ray, Boston Whaler, Bayliner), Malibu Boats (Malibu, Axis, Pursuit, Cobalt), Correct Craft (Nautique), MasterCraft, Marine Products (Chaparral, Robalo), Grady-White, Scout, Regal, Sea Fox, and Yellowfin, buy structural adhesive on specification and by the drum. Each has a written process that names the methacrylate grade, the bead size, the fixture time, and the surface prep, and each has years of warranty data behind that process. Brunswick and Malibu write those specifications centrally for several brands. The methacrylate supplier that holds the specification holds the account, and there has been one such supplier at nearly every builder for twenty years.

The pontoon builders, Polaris Marine (Bennington, Godfrey), Barletta, and Avalon, and the pontoon and aluminum brands inside Brunswick and White River Marine Group, buy very little structural adhesive and a great deal of everything else: carpet and woven vinyl flooring adhesive, upholstery adhesive through their furniture suppliers, butyl and polyurethane under rails and cleats, VHB under trim, harness tape and heat shrink. Their adhesive spend is spread across a dozen products and flows partly through Tier 1 shops in Elkhart County.

The offshore and custom builders, Viking Yachts, and the semi-custom end of Grady-White, Scout, and Yellowfin, run epoxy alongside or instead of methacrylate on infused and cold-molded structures, buy Sika glazing systems for large bonded glass, and follow the Sika teak deck process where they lay teak. They buy in smaller quantities, at higher prices, with more technical involvement.

Underneath all three sits the same bedding sealant. Every OEM on the list bedded fittings with 3M 5200 and 4200 or Sikaflex 291 this year, most of them wrote the part number into the process sheet a decade or more ago, and none of them has a reason to open the specification.

The full roster with scale band, product scope, and buying pattern, and the discussion of how a boatbuilder buys adhesive differently from how it buys resin and glass, is in the gated portion of this report.