Courtesy Finsulate Installing nontoxic Finsulate antifouling wrap on a large commercial vessel.
It’s rare to find a truly new approach to a problem that’s plagued seafarers for millennia, but Finsulate film wrap offers such a fix for marine fouling.
Life abounds in the ocean regardless of temperature or geography as nutrients and tiny aquatic plants and animals wash in and out with the constant rhythm of the tide and churn of waves. Because ocean food sources aren’t tied to a well-fertilized spot in the soil, many marine organisms have evolved to fix themselves to stable surfaces and feed on the smorgasbord of sustenance that drifts by. Predictably, they grow more successfully and more densely wherever there’s more food entrained in the water column, usually in the upper reaches where the smallest organisms float, some of them deriving energy from the sun, and others feeding on floating nutrients and plankton. It also happens to be where boat hulls float in a state of relatively constant immersion regardless of the state of the tide. No surprise then that hull bottoms and other floating structures present ideal residential opportunities for everything from a light algal film to thick matted ecosystems of seaweed, barnacles, tunicates, anemones, mussels, worms, etc.
As long as there have been even the most rudimentary of boats, their users have been challenged by marine growth slowing their progress through the water and destroying their structural integrity. Historically, boat builders and yards have applied oils, poisons, spices, and tars to hull bottoms with varying degrees of success. The most effective tend to have negative impacts on ocean health, which has led to regulatory tightening in recent decades as lead-, tin-, and copper-based paint formulations were widely banned or limited in their legal use. Now, in addition to the antifouling toxins in bottom paints, the plastic-based paint material has been found accumulating in marine environments, spurring efforts to develop more permanent coating solutions that don’t require annual renewal. Silicone-based coatings offered the promise of multi-year non-toxic antifouling, but difficult removal and replacement, as well as the risk of silicone contamination of other surfaces during application, earned them a mixed reputation among yard crews.
Enter Finsulate, a slightly elastic adhesive-backed polyester membrane with a fuzzy exterior surface of flocked nylon. Developed by Dutch researcher and passionate ocean diver Rik Breur, the surface has more in common with velvet upholstery than hard bottom paint. It’s the result of an epiphany Breur had while looking at a crab and an urchin side by side and noting that the smooth crab had barnacles growing on it while the spiney urchin was free of growth. After researching how short and fine the spines or fibers could be and still prevent growth from adhering and then exploring the infeasibility of spraying flocking directly on the hull, he committed to manufacturing a short-nap sheet material in a controlled industrial environment.
Courtesy Finsulate Many of the 900 boats fitted with Finsulate are recreational sailing vessels, for which the material is well suited. Installation is similar to hanging wallpaper.
Finsulate USA founder Bernard Hidier explained that the resulting product, which ships in rolls, is cut by trained crews and applied to bottom surfaces that have been prepared with a standard 2-part epoxy primer. On large boats it’s almost like hanging wallpaper, he said. On smaller vessels, fitting the film to complex edges and contours can take more time and finesse. But having coordinated numerous training sessions for yard crews, Hidier said, “Painters get it right away.” And they appreciate not having to suit up in protective gear to apply or remove toxic bottom paint, in what has become a standard annual ritual of boat maintenance. Indeed, because the Finsulate doesn’t shed any paint when a boat is hauled, many yards will be able to dispense with collection of residue and runoff from Finsulate boats.
“When you scrape and repaint, you need to do it in the proper place with the right gear, and you need to collect the pressure-wash water,” Hidier said. With Finsulate, he said, the bottom can be pressure washed or simply allowed to air dry, after which any remaining growth can be brushed off.
During hauling and storage, it’s prudent to protect the Finsulate surface from hard chafe on lifting straps and to place scrap cardboard between the hull and the jackstand pad. But come spring, there’s zero hull preparation necessary before launching. Hidier noted, it provides a lot more flexibility to yards and owners who want to get on the water as quickly as possible. And at a time when good service-yard workers are hard to get and keep, removing the nasty annual chore of scraping and reapplying antifouling paint is a net gain. For lager commercial vessels there’s also a saving in reducing downtime for maintenance.
Hidier said Finsulate is currently on about 900 boats worldwide; the earliest applications having surpassed the 10-year mark without needing replacement. That’s a lot of waste paint, haul-out time, and labor saved. When it must be replaced, old Finsulate is removed by applying moderate heat and pulling the membrane off in sheets. Hidier said, because the membrane is an effective protective coating, they find the epoxy painted surfaces underneath are usually in good condition requiring only cleaning before new Finsulate is applied.
Fixing damage from impact during service is a lot like repairing carpeting. With the boat hauled, a technician cuts a squared area and heats it to remove the damaged bit. Next, Having addressed any issues with the underlying surface, they cut a new piece of Finsulate slightly oversized to fill the bare patch and turn back the edges and trim them flush with the surrounding material to perfectly fill the void.
Courtesy Finsulate Visible here is the fuzzy surface of the film that inhibits growth and discourages attachment of marine organisms but doesn’t harm on-water performance of displacement hulls.
If you’ve been thinking a layer of short-nap fabric on the bottom would change a boat’s on-water performance, you’d be partly correct. Hidier explained that for displacement boats there’s no speed penalty as the nylon fiber remains fully submerged in water. Only when air is introduced to the running surface does friction increase. He said fast planing boats can expect to lose as much as a 25% off their top speed using the shortest nap of the three Finsulate options. At the other end of the spectrum, the longest nap membrane is effective for stationary floats, pilings, offshore platforms, and underwater pipes. Preventing marine fouling on these structures makes them far less vulnerable to damage from storms and high wave action. It’s also especially useful for aquaculture barges and floating assets where toxic antifouling is detrimental to farming operations.
Courtesy Finsulate Sheets of Finsulate are installed over epoxy primer by specially trained technicians.
Applicator training and industry acceptance are the greatest challenges Finsulate faces. Hidier said he’s optimistic that boat owners and yards will see the benefits as they use it. In the short term, he holds great hope for the superyacht industry which comprises large displacement hulls subject to myriad environmental and antifouling regulations as they move among Caribbean, North American, Mediterranean, northern European, and Pacific waters.
“Finsulate,” said Hidier, “is the only out-of-the-paint-box solution.”
