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post #1 of Old 06-22-2003 Thread Starter
Don Casey
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The Bottom Paint Blues

Anti-fouling protection—same as it ever was—messy, environmentally dangerous, and an odious chore.
Thirty years have passed since I bought my first "big" sailboat, a 27-footer from the drawing board of Carl Alberg. The deal had included a promise of a full-day orientation in combination with the sea trial—a bay trial, really. As we banged across a nasty chop (it was the kind of day that prudent sailors spend polishing brass at the dock), the seller offered bits of wisdom. Today I cannot recall his name, but I still quote him every time I begin the ritual of a post-sail washdown.

" the enemy," he told me then. " the enemy," I say today. The pause in that sentence makes it into a word association. I pass this catchy maxim along to you knowing that 30 years have not diminished its validity.

Another thing the seller told me 30 years ago was what bottom paint to use. The "best," as far as he was concerned, was Trinidad 75. That was the paint on my boat then. That is the still the paint on my boat today, but that fact points out a disappointing lack of technical advancement in bottom protection. How is it that there have been no significant improvements in 30 years?

The author's preferred Trinidad 75 paint hasn't changed much in 30 years.

It is not as if there is no room for improvement. After all, antifouling paints typically begin to lose their effectiveness in a year. That makes them only about twice as durable as, say, varnish, which many sailors refuse to have on their boats because they don’t want the upkeep. Yet we haul every year to sand and repaint the bottom, or we go in the water and scrub the bottom every fortnight to put off for a few extra months the inevitable haul-out. Would you put up with having to repaint your car every year?

I want a bottom coating that is as durable as the rest of the boat, but on the way to getting there, I can be content with a coating that lasts 10 years, even five years. The problem is that I see few signs that better bottom coatings are on the horizon.

Actually, there are some five-year coatings on the market. Tributyl tin (TBT) paints have been around for more than 40 years, and from the mid 1970s through the 1980s, they provided sailors with multiyear bottom protection, However, since 1989, they have been outlawed in the US except for protecting aluminum. The toxins these paints released not only poisoned marine creatures trying to attach themselves to the boat, they also proved lethal for fish and shellfish in the surrounding waters. TBT bottom paints are still sold outside the US, most notably in the Caribbean, but if you use these paints, you choose convenience over virtue. It is a choice you should not have to make.

Much of the blue anti-fouling paint that you don't see on this bottom has leeched off into the sea. Is this how we want to treat our sailing environs asks the author.

It has been more than a decade since the EPA banned tin-based paints. Copper-based paints have replaced them. Leaching copper is apparently less of an environmental insult, but anyone who has ever scrubbed a boat in the water knows in their heart of hearts that blue cloud can’t be doing marine life any good. The unavoidable truth is that most of every gallon of bottom paint manufactured—especially soft paints—ends up in our rivers, lakes, and oceans. This is hardly a cause for pride.

I am not calling for a ban of bottom paints. The idea of a legislative solution holds little appeal. When governments get involved, the results are rarely satisfactory. Marine sanitation laws are a case in point. Discharge bans are almost entirely without merit except where there is high concentration of liveaboard boats in a confined body of water. Yet many if not most sailors support these laws based on a misguided sense of good citizenry. Meanwhile, these very same sailors (I include myself) are effectively dumping a gallon or more of toxic paint into the water every year. Which do you think is likely to be more harmful, the residue of digestion or a pesticide mixture brewed up in a lead vat?

"Which do you think is more harmful, the residue of digestion or a pesticide mixture brewed up in a lead vat?"
For centuries builders and owners protected their vessels by sheathing the bottom with copper plates. Nailing copper sheathing to a fiberglass hull is problematic, but at least a couple of innovators have tried to develop methods of adhering copper foil to fiberglass. Despite being even older technology than paint, copper sheathing promises the kind of long-term antifouling performance we should expect in the 21st century. And it seems more environmentally responsible. Unfortunately, the adhesives have proven less durable than the copper, and these admirable efforts appear to have been abandoned.

The problem, it seems to me, is that these have been individual initiatives, lacking the R & D budget a large corporation might bring to such an effort. If there are glues capable of holding the windshield in your car and glues capable of bonding heat-resistant tiles to the underbelly of the space shuttle, surely there is a glue out there that can hold foil to fiberglass underwater.

Carrying this thought one step farther, I see little reason why an innovative boat manufacturer could not develop a method of giving the hull an antifouling surface below the waterline right out of the mold. I imagine heavy copper foil, computer cut to lie smoothly in the mold, forming the bottom layer of the layup process. Hulls like this could be warranted to repel hard growth for 10 years. As an added attraction, it should be more effective than current measures at eliminating the threat of osmotic blisters.

A currently available cousin to sheathing is copper loaded resin. Here epoxy is loaded with copper flakes to yield a "copper" bottom. More mosaic than veneer, this type of coating has proven effective against barnacles but it does little to resist grassy growth because of the small amount of toxicant released into the water. Copper-loaded resins are environmentally superior to paints for the same reason. Grass scrubs off easily enough, and those committed to the "clean wake" philosophy may find periodic brushing a fair trade-off. A copper bottom should last a decade or longer. Of course seasonal sailors would need to "activate" the copper with an abrasive scrub before their spring launch.

Will bottom paints ever be replaced by more sophisticated, eco-safe anti-fouling systems?

The Interlux company deserves to be singled out for its ongoing effort to develop a totally non-toxic bottom coating. With the introduction of Veridian nearly a decade ago, Interlux brought a long-overdue live-and-let-live philosophy to the fouling arena. Instead of poisoning marine growth, this super-slick silicone coating just makes it difficult for the growth to get a grip. Motion keeps the bottom of an oft-used boat clean. Growth that does attach wipes away with a sponge. The slick bottom also makes the boat faster and improves fuel economy.

Cost has been Veridian’s dark side. There has been little demand for it because it is so expensive, and it is so expensive because there is little demand for it. If more of us expressed an interest in this type of product. Interlux would surely find a way to make it available at a more palatable price. The life span of this paint is said to be five years, but who knows? Until a few sailors get some experience with this type of product, it is just another "interesting concept."

The only way that better products will come to the market is if we demand them. If you agree that dumping tens of thousands of gallons of pesticide into coastal waters every year

"The only way that better products will come to the market is if we demand them."
is unbecoming of those who claim to love the water; if you think hauling to paint every year or every other year is retarded, complain to the manufacturer of the bottom paint you are using. Write them. E-mail them. Talk to them face-to-face at boat shows. Paint companies know, beyond any doubt, that it is only a matter of time until the current generation of bottom paints will be outlawed by legislative edict. But if they thought we sailors, we boaters, cared about this issue, perhaps at least one company would give us a better choice. That is all it would take. The other companies would be forced to follow suit.

Meanwhile, maybe there is a boat company planning to sweep the competition with a non-fouling hull. Or maybe some out-of-work dot-commer has been putting that idle creativity to work conceiving an entirely new solution.

If not, there ain’t no cure for the bottom-paint blues.

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