In his essay The Much Repeated Repetition-a phrase that could well apply to our semi-annual antifouling paint reports-writer G.K. Chesterton quipped that the study of human history defied science because, contrary to the old adage, it did not repeat itself. Fortunately, our bottom paint test results do repeat themselves, at least to a degree that they can yield some useful data. We are quite sure of this, although our confidence might be just another sign that weve been sniffing bottom paint for too long. As Chesterton also said, Madmen never have doubts.
Over the past five years, weve reported on three different sets of bottom paint panels that have been immersed in saltwater for at least two years-a set immersed in 2008, one in 2009, and one in 2010. We have now retired all three.
With the exception of some new paints launched in the latter years, each panel set contained the same roster of bottom paints. These 60 to 70 antifouling paints represent nearly all of the coatings used by recreational sailors in North America. In the end, only seven paints proved capable of combatting barnacles after 24 months on each of the panel sets. We consider these paints (indicated in bold in the adjacent list) to be the most reliable antifouling paints available for the cruising sailor. Another 13 paints combatted barnacles on two out of the three panel sets at the 24-month mark. Only one copper-free paint, EpaintsEP 2000, has ever lasted 24 months, and this was on only one of the panel sets.
Altogether, then, weve identified 20 excellent bottom paints available to sailors today that should prevent hard growth for 24 months in conditions similar to those at our test site in Sarasota Bay, Fla. Because fouling conditions vary greatly by region, there are no guarantees, but given that these paints have repeatedly risen to the top in our tests, and our Sarasota results usually correlate with simultaneous field tests we conduct in other waters, chances are good that you will see the same performance.
These paints are generally well-suited for those who want long-term protection. They are not the cheapest available, nor the most cost effective for a sailor who repaints his hull each season. For single-season protection, we recommend one of our Budget Buy paints indicated in the accompanying Value Guide tables, or in the October 2012 issue.
Some of the paints on the Top 20 list serve specialized purposes, so cross-reference them with the tables to ensure your choice matches your needs. Note that Epaints EP 2000 and Blue Waters Copper Pro and Copper Shield lines have new formulas, which we have tested only once to the 22-month mark. (See table on right.) Also note that the two least expensive paints on this list, Sea Hawk Sharkskin and Blue Water Copper Shied 45 Hard, usually showed more soft growth than the more expensive paints from their respective makers.
Current Testing
In this issue, we offer an update on three different test panels-after 33 months, 22 months, and 11 months in the water.
The 33-month panels are dead. You might be able to stretch life out of these paints in crystal waters, but don’t count on it. Six months ago, we had three Good paints (minimal slime), now we have just two. And of the 27 paints that rated Fair (heavier slime, but no hard growth), were down to just 17 paints now. Fifteen paints made it 30 months in 2012 (PS, March 2012).
The 22-month panel set is also showing performance declines. These panels highlight some second-generation eco-friendly paints, new water-based paints, and some new dual-resin blends. The latter are doing well. Also in that group is the widely marketed two-part Eco-Clad system. A summary of findings from that panel set is on page 11.
The 11-month panel set again highlights new paints, and this is our first real look at how these paints are doing. Youll find details regarding this panel set on page 12.
When choosing a paint, make sure it is compatible with your existing paint, or be prepared for whatever extra prep work might be required. Usually, all that is required is some light sanding, and possibly, a primer coat, although in some cases, more aggressive sanding and surface prep is required.
Second, make sure the paint matches your needs. Most paints are formulated for specific conditions. We loosely classify bottom paints into two categories: hard paints and ablative paints. Hard paints hold up well to underwater cleaning and can usually be burnished smooth for racing. However, they leave behind paint layers that build up and eventually will need to be sanded off. Also, hard paints can require a light sanding before re-launch, or even lose their punch altogether if they are stored ashore for too long. Most ablatives can be hauled and re-launched without worries.
Ablative paints wear away, so they don’t build up paint layers over time. There are two main types-bottom-tier workboat ablatives that slough away to activate more biocide, and more expensive copolymer ablatives that release biocides at a more controlled rate.
Although ablatives are sometimes called soft paints, some, like the new dual-resin ablatives, are relatively hard. These will usually resist light underwater cleaning and are suitable for trailering.
The hard and ablative paints are further divided into five broad sub-categories that often overlap: freshwater paints, aluminum paints, racing paints, water-based paints (easy for the do-it-yourselfer to apply), and eco-friendly paints. Paint types are indicated in the accompanying tables, and the best paints in each category earn Recommended ratings.
The March 2012 report also breaks down the order of failure by paint type. In general, the order of failure is, first to last: freshwater, eco-friendly, low-copper single-season, water-based paints, high-copper multi-season ablative, and high-copper multi-season hard. Whether or not a paint has a biocide-booster does not seem to make a significant difference by the two-year mark in our tests, but biocides clearly help combat slime during the first year or so.
For more on selecting paints, see the blog post Choosing a Bottom Paint for Dummies, Aug. 31, 2011.
What We Tested
This article focuses principally on the 33-month antifouling paint panels. Results are posted in the tables on pages 8 and 9. The panels comprise 56 different bottom paints that PS began testing in November 2010 at the Sarasota Sailing Squadron in Sarasota, Fla. The panels were pulled and rated in August 2013. The participating companies include Blue Water Paints, Interlux, Epaint, Pettit, and Sea Hawk.
All paints were rated Good (relatively little soft growth), Fair (significant soft growth), or Poor (hard growth). There were no Excellent (spotless) paints after 33 months. See the accompanying How We Tested for details on the test procedures.
Blue Water
New Jersey-based Blue Water Paints had three survivors from its original six-paint field. The hard paints fared best, with both Copper Pro SCX 67 Hard and Copper Shield 45 Hard showing only soft growth. The more expensive Copper Pro SCX 67 Hard was clearly the better paint, with much lighter growth. Among Blue Waters ablative paints, the only barnacle-free coating was the top-of-the-line, copper-laden Copper Pro SCX 67, which contains the slime-fighting additive Irgarol. Kolor, Blue Waters bright-color/aluminum-safe paint, had a barnacle farm at 33 months, but it still ranks well in the aluminum-friendly, copper-free class.
Blue Water Paints are also available under the MarPro label through its website, at boatyards, or through distributor Donovan Marine (www.donovanmarine.com).
Epaint
After starting our test with four copper-free varieties (three hard paints and one ablative), Epaints was down to two contenders at 20 months, and by 26 months, those two had bit the dust. However, as we see in the newer 11- and 22-month panel sets, some of Epaints antifoulants do exceptionally well in the short term. In the past few years, EP 2000 has consistently been the cleanest or one of the cleanest panels in the 12- to 15-month checkups. Keep in mind that all Epaint coatings are activated by sunlight, which is in short supply in some places.
Epaint products were once limited to white or gray, but the company has been testing some new blends in different colors. At 11 months (see page 12), an experimental green formula, ZO-Plus 205, was doing well, but it lagged behind two other Epaint blends, EP-21 and EP 2000. ZO, ZO HP, EP-21, and SN-1 can safely be used over most hard antifouling paints with minimal prep. EP 2000 requires old paint to be removed.
Interlux
Most of Interluxs ablative paints are controlled release, so once the paint is in the water, the clock is ticking. While you can sometimes squeeze another year out of a copper-laden hard paint with more frequently cleaning, trying this with an ablative paint accelerates wear. All but one of Interluxs best ablatives were goners by 33 months, and this was not unexpected. The lone wolf still standing was Micron 66, a paint weve put to the trial on several boats and in several locales, and it has consistently done well. The downside of Micron 66 is that it will not work in fresh water. If you are looking for a budget ablative, Fiberglass Bottomkote ACT was near the top at the 26-month mark. In the hard-paint category, the Irgarol-boosted Ultra has proven again that it can go the distance. In a less fertile environment, you might be able to stretch another month or two out of it with regular cleaning, but its antifouling abilities against slime were sorely diminished at 33 months.
Pettit/West Marine
Pettit (a Kop-Coat Marine Group brand) had several paints that scored Fair or better in this final evaluation, and it was the only company with paints that scored Good. Both Trinidad Pro, the cleanest paint in the panel set, and Trinidad SR stood up to hard growth. Both panels had soft growth, but it was a thin layer that could be easily scrubbed away. These paints, along with the other Pettit front-runner, Trinidad, would be a suitable choice for a warm-water cruiser who wants to prolong coverage with scrubbing-so long as he accepts the inevitable paint-removal project down the road. Among the ablative paints, the water-based Hydrocoat, and the multi-season copolymer Horizons, were alive, but barely. Hydrocoat SR, which has an anti-slime additive, is also doing well in our 22-month test. This test did not include one of Pettits more potent ablatives, Ultima SR60, but it will appear in future tests.
Sea Hawk
Among Sea Hawks five hard paints in this panel set, only one survived: Tropikote Biocide Plus, an Irgarol-boosted paint that sells for more than $200 per gallon.
Although it had a few barnacles at 26 months (technically a failure), Tropikote without booster showed no additional hard growth at this checkup, suggesting there was still some potency in this formula. In the ablatives, two biocide-boosted paints, Biocop TF and Cukote Biocide Plus, are doing well. After a series of forgettable experiences with various experimental copper-free paints, the owner of one of our test boats in Sarasota Bay opted for Biocop TF, and it is showing only waterline slime at 11 months.
West Marine
West Marine contracts with Pettit to develop a short list of formulas to meet the needs of the average types of boater. The three West Marine ablative paints in this panel set were also sold under the Pettit label. The hard paint, West Marine Bottomshield, is a unique, recently reformulated coating that has shown middling performance in our tests. Because the company is interested in new (mostly eco-friendly) formulas, its product lineup changes. For example, the only paint that survived in this panel set, the water-based West Marine Ablative, has been replaced by a newer, eco-friendly formula CFA ECO. West Marine PCA Gold, a consistently good performer in previous tests, was among the cleanest of our failed panels.
Conclusion
The 33-month panels are done. Kaput. If your paint lasts this long, drink the water, its gotta be magic. Most of the paints were good and gone at 26 months, but out of curiosity and in response to reader queries, we pushed it another eight months.
The results bear out what weve said before, if youre a seasonal sailor who repaints every season, any of our Recommended or Budget Buy ablatives will do well. A hard paint would not be a first choice for a boat that repaints annually because of the build-up.
If you intend to haul out and relaunch, then we would recommend a paint designed to meet that purpose. Most of the Good ablative paints will not lose their effectiveness during storage out of the water. Hard paints, like Pettit Trinidad or Interlux Ultra, can also be re-activated by sanding after a prolonged haulout, but hard paints are generally a better fit for boaters who are staying in the water year-round.
As we saw in this test, you might be able to squeeze a bit more mileage out of a hard paint with some scrubbing. Adding a third coat of an ablative paint can also extend your time in the water. If you are a full-time cruiser and are torn between hard and ablative, we would lean toward ablatives. An exception might be a cruiser who really doesn’t want to haul out at year two or three, and doesn’t mind diving his hull on a bi-weekly basis.
Weve retired these panels for good, replacing them with a new crop of 66 different paints. This new set includes many of the same paints, several of the newer paints rated in the accompanying articles, and some paints we had not yet tested. As always, we enjoy receiving field reports from sailors who care to share their bottom paint experiences. Send them to practicalsailor@belvoirpubs.com; put bottom paint report in the subject line.
