Mike's Daring Experiments with Antifouling Paint

Posted by at 05:44PM - Comments: (5)

September 18, 2012

Skimmer's hull had a healthy coat of barnacles and soft growth after six months, despite regular cleanings.

Practical Sailor owes a debt of gratitude to Sarasota, Fla., sailor Mike Collins, who offered his Cape Dory 25, Skimmer, as a test platform for a new environmentally friendly bottom paint earlier this year. The paint had done well early in our panel testing, and Collins, who oversees the health of the aquariums at Mote Marine Laboratory in Sarasota, was as curious as we were to see how it might perform on a hull. So how did it do? This photo of Skimmer’s bottom, taken just six months after the bottom was painted, says it all.

It is important to point out that the paint, Sea Hawk’s Smart Solutions, was an early formulation of an antifouling coating that contains no metal, not even the relatively benign zinc that other “green” paints rely on to fight barnacles. Designed for application by a professional, Smart Solutions is a specialized formula for low- to moderate-fouling areas. Sea Hawk would not normally recommend the paint for people like Collins who sail in warm waters known for heavy fouling, but they gamely agreed to participate in our test as it was being carried out in conjunction with our test of ultrasonic antifouling. The formula that Collins applied in February has since been modified, and although we have not yet tested the newer blend, Sea Hawk reports that it is getting better results.

This isn’t the first time Collins, an avid club racer out of the Sarasota Sailing Squadron, has sacrificed a slick hull for PS readers. Two years ago, Interlux introduced its new Pacifica blend, a formula designed to meet strict environmental rules that were being introduced on the West Coast. Shortly after Skimmer’s slick Pacifica-blue bottom splashed into the bay, Interlux announced the introduction of (ta-da!) Pacifica Plus. The original formula, as Collins soon found out, lacked the sort of punch Interlux had observed in early testing. That Collins agreed to be a guinea pig again is testimony to his commitment to the copper-free cause.         

We are often asked about new eco-friendly alternatives to copper-based antifouling paints, and our rule of thumb with these new paints is to wait to buy it until the paint has been on the market for two seasons. This allows time to gauge other boaters’ experiences with the new blends and see how the paints do in Practical Sailor's testing. Although these paints go through extensive trials prior to their introduction to the market, we’ve seen some “game-changing” eco-paint flop after less than 12 months in the water. With rare exception, only those paints that contain cuprous oxide have fended off barnacles for longer than 18 months in our testing.

In the most recent round of testing after nine months, the blends boosted by the newest magic bullet—the "green" pesticide Econea—are delivering Fair to Good protection, well below their copper-fortified peers. One new paint that is doing well is a reformulated blend of Epaint’s SN-1, an aluminum-friendly, two-part paint that requires professional application.

Interestingly, the same Smart Solutions formula that Collins had on his boat is still barnacle-free in our panel testing, which is carried out at a dock near where Collins’s boat is moored. We still don’t have an explanation for this, but Sea Hawk’s experts suggested that since this early formula was softer than the newest blend, the coating may have worn-away faster on Collins’s boat that on our panel. Skimmer also sees more sunlight on its mooring than our panels do.

Although we are not fans of the growing movement to ban or sharply reduce copper in bottom paints for well-flushed marine environments, we are glad to see that companies like Eco-Clad, Epaint, Flexdel, Interlux, Luritek, Pettit, and Sea Hawk are exploring new formulas that can help to reduce boaters’ environmental impact.

As for Collins, his commitment to the anti-copper cause is on pause for the moment. Once the barnacles were scraped clean from Skimmer this time, he opted to apply Biocop TF, one of Sea Hawk’s high-copper blends specifically formulated for high-fouling waters. We’ll check in again in six months to see whether he’s still smiling.

Comments (5)

The Smart Solutions has been getting good reviews from the aluminum boat crowd that just don't want copper any where near there bottom even with good epoxy coatings. Note in the article it says "even with regular cleanings" Sea Hawk specifically says not to scrub this paint. at most a light wiping with a glove. It is a very soft paint. They are working on a harder version...

Posted by: FL Capt | November 28, 2012 12:11 AM    Report this comment

Thanks for the advise to buy "Offshore Sailing" by Bill Seifert. It's a "must have" for every sailor, I've really enjoyed it.

Tim Benner

Posted by: Timothy B | September 20, 2012 9:07 PM    Report this comment

Since it might appear that copper-free is not ready for prime time, I am interested in hearing about alternative ways to reduce copper emissions using paints that are more effective. Maybe, for now, half a loaf is better than no loaf.

Soft ablative paints slough off relatively quickly, and one would think that they therefore emit more copper into the water than, say, a semi-ablative copolymer "hybrid" paint like Pettit Vivid (which I happen to use on my boat). True hard paints might be expected to emit even less copper into the water than a same-ablative paint, but they lose their effectiveness if hauled out for the winter (as those of us in the northeast US typically have to do).

Has PS or anyone else studied the correlation between a paint's hardness and the actual emission of copper into the water? It seems possible that increased use of semi-ablative or hard paints might provide a gradual reduction in copper emissions while we wait for the R&D guys to come up with a more effective copper-free alternative.

FYI, I've spent my 25 year career in paint, ink, and polymer R&D, so that experience is what led to this question.

Posted by: Take Five | September 20, 2012 7:06 AM    Report this comment

It is studies like these that make Practical Sailor such a great investment. Clearly, the "eco-friendly" paints are not even close to being on par with copper paints, and with their significantly increased cost (as well as the cost and environmental impact of having to remove all previous bottom paint, I can't see why anyone would purchase them now. Paint manufacturers take note: twice-the-price and half-the-performance is not a good business model. I will be staying with copper.

Posted by: PharmBoy | September 19, 2012 12:49 PM    Report this comment

I have a 40' powerboat sailing --- (ooops!) motoring --- out of Baltimore, cruising the northern Chesapeake. Sea Hawk's Smart Solutions paint performance has been very disappointing. It was applied in April of 2011 and couldn't prevent hull buildup for even six months. The boat is now in the yard, having the paint removed. I must commend Sea Hawk for standing by its product's lackluster performance and by its commitment to customer service. Sea Hawk has replaced the Smart Solutions with its AF33 "real" bottom paint. I adhere to the precepts of environmental protection, but not when I have to resort to short-hauling and power-washing the hull every six weeks just to get up on plane.

Posted by: Ted TZ | September 19, 2012 11:09 AM    Report this comment


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