Sure, grading antifouling paint panels probably doesn’t qualify for the television show “Dirty Jobs,” but after 20-plus years of counting barnacles, ones mind does wander toward a spring that doesn’t include resins, heavy metals, and solvents.
That is why this springs bottom paint report is so much more exciting than our previous reports. (Really, we promise.) The year 2010, you see, marks a significant shift toward environmentally-friendly bottom paints.
The epicenter of this movement is San Diego, Calif., home of one of the nations busiest ports, a U.S. Navy base, and more than 17,000 boaters. More significantly, it is also home to the Scripps Institute of Oceanography, one of the nations most highly regarded marine research centers. Sharing the waterfront with dozens of doctoral-seeking biologists is a double-edged sword for boaters. On one side, there is no shortage of reliable water-quality data. On the other hand, that data might well lead to laws that lead to your wallet.
Scientists have known for years that San Diego harbor has unusually high levels of copper, but only recently have regional authorities been given the funds and regulatory tools to try to address this problem. Currently, the local water-quality districts have set incremental goals of reducing copper levels in the port waters by 76 percent by 2022.
With the help of about $200,000 from the Environmental Protection Agency, the port is into its second round of no-copper or low-copper paint tests, and most of the major antifouling paint makers have signed on to participate.
So, while San Diego dips into paint evaluations on the West Coast, we plough ahead with our second decade of studies in the East. This report tracks the performance of more than five-dozen paints after six months immersion in Florida. The test primarily covers conventional copper-based antifouling paints, but (and this is the exciting part) it also presents the very first look at the latest no-copper concoctions.
What We Tested
This six-month update covers 65 anti-fouling paints that were submerged in June 2009 in Sarasota, Fla. and inspected in January 2010. (See page 24 for results on a separate set of 18-month panels; the results of field tests on various boats are on page 26). The players include six familiar names-Blue Water, Epaint, Flexdel, Interlux, Pettit, and Sea Hawk-and one newcomer, Copper Coat, an epoxy-copper blend that claims multi-year protection. An experimental stick-on antifouling, BoatKoat Laminate also joined the field.
The six-month results are tabulated on pages 22 and 23, which are split between hard and ablative paints. The two types of paints work differently, but for most sailors, the key distinction is the maintenance regimen for each.
Hard paints resist scrubbing well and can usually be burnished smooth for racing. However, they leave behind resins and pigments that build up over the years and will eventually need to be sanded off. Also, many hard paints lose their punch when they are stored out of the water for long periods.
Ablative paints wear away through use, so they don’t build up thick layers. Basic workboat ablatives slough away with water friction to expose more biocide. Other, copolymer ablatives release biocides at a controlled rate. Although some “hard” ablative paints resist light scrubbing and are suitable for trailering or racing, ablatives generally wont tolerate abrasion like most hard paints.
Cuprous oxide (or copper thiocyanate in aluminum-friendly paints) is the primary biocide in most of the tested paints, but some also add algacides such as Irgarol (NCN), and biocide boosters such as zinc omadine and zinc pyrithion. The blends yield paints for specific needs: freshwater paints, aluminum paints, racing paints, water-based paints (easy for the do-it-yourselfer to apply), and eco-friendly paints. Weve flagged the best of each of these subcategories with Recommended check marks in the tables.
Whatever type of paint you buy, check the application guidelines to be sure it is compatible with the paint you have on your boat. If in doubt about prep work, ask the paint maker for guidance.
How We Tested
Each test involves one fiberglass panel set: The six-month set was hung from a dock on Sarasota Bay in Sarasota, Fla.; the 18-month panels were suspended in a canal in Key Largo. (Look for a two-year update on another panel set in Connecticut this fall.) Following the makers instructions for preparation and number of coats (usually two), testers applied 10 samples per 6-foot-by-2-foot-long panel.
Prior to rating, testers sluice the panels with a bucket of salt water. Paints were rated Excellent (no growth), Good (light growth), Fair (moderate to heavy soft growth), and Poor (hard growth). Any paint that rates Fair or better has generally met its designed purpose.
A Recommended paint is one that performs best overall or rates best among its specialized peers (best aluminum-safe paint, best water-based paint, best racing paint, etc.). The Budget Buy paints represent the least expensive among Recommended paints.
Remember: Any antifouling paint test is subject to a number of variables, and we recommend supplementing our data with local knowledge from other independent sources.
Findings
Nearly all of the paints repelled barnacles at the six-month mark and would easily clean with a sponge. Panels with barnacles could still be pressure-washed clean. If you want long-term protection, check the 18-month tables. Some paints are like Aesops hare: They start off amazingly clean for six to 12 months, but then lose potency. Others are tortoises: They are average slime-fighters at first, but they win the endurance race, fighting off barnacles for 18 months or longer.
Blue Water
Blue Water reformulated all its paints for 2009 with good results. It scored particularly well in the lower price range ablative paints. Its new Aqua Shield 45 kept up with other water-based ablative paints near the $100-per-gallon mark. Its economy hard paint Copper Shield 45 also did well. Blue Water offers most of its formulas with and without added algacides or boosters. At six months, most of the non-boosted blends did as well or better than the more expensive boosted blends. Blue Water Paints are also available at boatyards and through distributor Donovan Marine (www.donovanmarine.com) under the MarPro label.
Epaint
Specializing in copper-free paints, Epaint was one of the big winners at the six-month mark, with three of its four paints coming out virtually clean of any growth. Standouts among its hard paints were ZO-HP, an abrasion-resistant paint that can be sanded to a very smooth finish for racing, and EP2000, a consistently good performer in the aluminum-friendly category. The one-season freshwater paint EP-21 was among the cleanest of all the ablatives. Because Epaints are photoactive, they will ablate faster in warm, sunny waters, and at least one extra coat near the waterline is recommended. EP2000 isn’t compatible with other bottom paints, so switching paints requires significant prep work.
Flexdel
Based on these six-month results and our recent field test, Flexdels water-based and aluminum-friendly Aquaguard competes closely with Pettits Hydrocoat, a similar water-based blend. At the six-month checkup, Aquaguard was doing a better job at combatting slime. However, in the field test, Hydrocoat had fewer barnacles. Staying barnacle-free for 15 months or more with either paint will likely require bottom cleaning.
Interlux
Interluxs Micron 66 has done consistently well in our long-term testing over the past five years. This paint is particularly potent during the first six to eight months or so, when almost nothing seems to grow on it. Micron CSC wasnt far behind in slime fighting, followed by Fiberglass ACT and budget-priced soft workboat paint Bottomkote. In the hard paint category, water-based Bottomkote Aqua, slick freshwater racing paint VC-17m Extra, and VC Offshore racing paint all scored well in their respective categories. Ultra, a paint that has done well in the past, had several barnacles.
Pettit/WEst Marine
Pettit was the first major player to launch a paint with the new biocide Econea, which is getting a lot of hype in mainstream media. Early results are good, but not stellar. The paint, Vivid Eco, was relatively clean, but not a standout, at six months. Its experimental Hydrocoat Eco-also with Econea-succumbed to hard growth in our 18-month test.
Pettit scored a nearly clean sweep in the hard paint division. Among the expensive hard paints, regular Trinidad edged the more expensive biocide-boosted Trinidad SR this time, although previous longer-term tests have put Trinidad SR on top. Unepoxy has been a consistent performer among budget hard paints.
In the ablatives, the West Marine CPP and the West Marine PCA Gold offer good protection, as did the Ultima SR 40 and Ultima SSA. Several barnacles made themselves comfortable on a panel painted with the new Ultima Fusion. Pettits aluminum-friendly Vivid Free and Alumacoat SR paints (identical blends with marketing monikers) scored Excellent.
Sea Hawk
Sea Hawks best performer at six months was its California-inspired eco-paint, Mission Bay, a zinc-omadine formula that came up nearly clean of any growth. Second was Islands 77 Plus, a biocide-boosted ablative paint designed-as the name implies-for island cruising. Although this formula has 7 percent less copper than its previous formula, the switch from biocide-booster zinc pyrithione to zinc omadine appears to have offset the copper reduction. Among the hard paints, its copper-laden Monterey and Tropikote Biocide Plus stood out. Sea Hawks new metal-free paint (the only one on the market), Smart Solutions was not a top slime fighter, but it held barnacles at bay.
Copper Coat
Promoted as a powerful paint that can last up to 10 years, Copper Coat showed no sign of barnacles at six months, but it had more slime than the majority of the other panels. This three-part, high-solvent epoxy coating, requires careful application and cannot be applied over previous coatings. The product is relatively expensive, and whether it is worth the extra expense will depend on whether it lives up to its claims. The makers call for regular hull cleaning to prevent the buildup of slime.
BoatKoat Laminates
The prize for the most novel approach to antifouling goes to the stick-on laminate from BoatKoat Laminates, of Clermont, Fla. The product, still in development, comes in long, recyclable, sticky, antifouling-laced rolls that are “taped” to the hull like shingles (or fish scales). This stick-on and peel-off approach could significantly reduce the amount of airborne and waterborne copper generated at boatyards. It also allows new boat owners to preserve their original gel coat. However, testers noted five barnacles on the BoatKoat panel. The maker is developing a more potent blend.
Conclusion
This six-month update shouldnt guide a search for long-term protection, but it is an excellent resource for two types of sailors: one, the sailor who wants a super clean bottom for the summer season without having to scrub, and the sailor who hauls and paints his boat every year.
If you are in the first group, consider the four ablative paints that rated excellent-Micron 66 (saltwater only), EP-21 (freshwater), Pettits Alumacoat SR and Vivid Free (aluminum-friendly)-or Epaints two Excellent hard paints EP2000 or ZO-HP. Keep in mind, however, that only one of these paints, Micron 66, has consistently been a two-year finalist in our tests.
If you haul out and paint annually, look for the least-expensive ablative that rated Good and meets your specific needs. Ablative is preferable because if you are painting every year, youll build up hard coatings fast. In this test, seven such paint were priced at about $120 or less: Blue Waters Copper Shield 45 and Aqua Shield 45, Flexdel Aquaguard, Interlux Bottomkote ACT, Interlux Bottomkote, West Marine CPP Plus, and Sea Hawk Monterrey.
Past PS tests have shown that, except where noted, the best-rated saltwater paints also excel in fresh water. However, lake sailors should closely consider hard, low-copper or no-copper, fresh water paints that reduce their impact on the environment.
As for the march toward eco-friendly marine paints, so far none of the newest formulas boost our hopes in that area. If you want to join the eco-train, EP2000 or Z0-HP are excellent bets, but the prep work for EP2000 can be significant. If you want to baby-step toward a greener bottom coating, but still want an ablative coating, consider a water-based, low- or no-copper ablative. Again, if you go past the 12-month mark free of barnacles with any of these eco-paints, you are doing well.
