Features April 1, 2003 Issue

Bottom Paints 2003

It's baaack... Micron Optima earns the overall best rating. Interlux and the Kop-Coat companies take 10 of 13 'excellent' ratings, Sea Hawk gets two, and E-Paint one. Pettit Ultima SR looks good long-term.

Just in time for commissioning chores in temperate climes, here are the results from our 12th annual bottom paint tests. These are among the more involved full-time tests we do, especially since we started rigging panels in both Connecticut and Florida a couple of years ago. The practical analysis isn't complicated—the ratings themselves take a small fraction of the prep and test time—but the topic is really interesting when you consider the variations in paints and test conditions over the long haul. As one reader wrote, it takes years to see which paints behave well consistently. 

What, you were expecting Sandra Bullock with the paint? These are the Connecticut panels just after being hauled out and sluiced off. They had been been tied in a loop, paint-side out, and shifted regularly during their immersion.

This year we show results for 53 coatings, including 11 products that are either new, new to these tests, or reintroduced, as follows: Z-Spar Protector (TF) from Kop-Coat, Bottomcoat XXX from Interlux, Fiberglass Bottomkote Aqua from Interlux, Trilux from Interlux, SeaLife 1000 from Sea Life Corp. in California, Regatta from Interlux, Sea Jacket from Gloucester (Interlux), VC-17 Extra from Interlux, EP-ZO from E-Paint, Slick Barrier (formerly known as Bye-Bye Barnacles) from United Energy Corp.,and Micron Optima from Interlux. We rated Optima highly for several years, but last year it wasn't available on the US market when our test panels went in the water, so we had to skip it. This year it's back, and, to cut to the chase, it's the overall winner. But read on—we put a lot of work into these tests.

Test Procedures
Each year we use new pre-cut sheets of standard polyester-resin fiberglass. The sheets are scrubbed with a commercial de-waxer, then thoroughly sanded and washed again with de-waxer/solvent. Then the sheets are taped off, and bottom paint is applied according to the directions on the can labels, including any required pre-treatments or priming. Unless otherwise instructed, we apply two coats of paint. Drying instructions are followed exactly. Only one side of each panel is painted; the other side is left bare.

Paints are assigned identifying marks—a series of large and small holes drilled in a binary code that correspond to numerical IDs on our working chart. This has proved a very reliable marking system, no matter how bad the fouling.

Last year, Foulbottom II, our test raft in Connecticut, met its demise on the frigid day we took the panels off for inspection. Having tired of wading around for hours knee-deep in muck and guano and hip-deep in icewater in order to attend to matters, we removed the panels and chainsawed the raft, with some satisfaction, into its essential elements.

We had planned, after that, to duplicate the Florida panel-mounting procedure in Connecticut—simply bolt them to PVC pipes and fix them underwater. However, as we were considering that, we received a letter from the makers of Sea Hawk paints, who, stung by a drop in a couple of their ratings, criticized our test procedures (the same ones in which they'd tested well before).

After a great deal of careful analysis of our methods, and consultation with paint industry experts, we didn't find that our procedures were out of line, especially given the number of variables that can affect how a paint fares year to year, and the fact that our ratings have always been simple, common-sense, and subjective. However, as we said in a reply to the Sea Hawk letter, we couldn't rule out the possibility that panels can be mounted in positions of relative advantage or disadvantage. In fact, as far as we can tell, no one who tests bottom paints "in the wild" can entirely rule out that possibility.

So, for the Connecticut tests this time around, we tried something a bit different: We laid out the six panels, each with nine paint positions, one above the other, strung them with polypropylene line, then tied them in a loop with the paints facing out. We hung this arrangement underwater from a floating dock with clear water and strong tidal current. Then, throughout out the summer and early fall of 2002 we regularly rotated the loop one "notch" at a time, so that every paint saw different depths and orientations several times.

In Key Largo, Florida, we did things exactly as we had the year before: The panels were drilled in the corners, suspended underwater on PVC pipes from a dock in a waterway, and left entirely to themselves.

In both areas, paint samples were assigned positions on the panels completely at random, and weren't identified until their codes were cross-checked with the chart at left. The Connecticut panels were submerged for five months, from mid-June to mid-November 2002; the Florida panels were under from late June until mid-February 2003, or about seven and a half months.

Rating System
As readers know, we try to stick with a four-level rating system—poor, fair, good, and excellent. As defined for last year's evaluations, an "excellent" rating meant that the panel was completely free of growth; "good" meant that a significant portion of the panel, say a third to a half of the surface, showed growth; "fair" meant that most or all of the panel showed a thin layer of growth; and "poor" meant that most or all of the panel was obscured in a heavier layer of growth.

This year in Connecticut the panels as a group looked significantly better than they did last year, certainly due to the cleaner water and better tidal current. (Other factors like salinity and seasonal temperatures make a difference, too, but we can't account for them.) While the "excellent" and "poor" ratings mean essentially the same thing this year, "fair" and good" were harder to assign, simply because the growth was sparser, and trying to measure little blotches of brown in some combination of area and depth isn't practical or necessary. In the middle ranges, therefore, panels are rated relative to each other as much as against objective extremes, and we've resorted to an extra "+" here and there to differentiate.

Only a couple of panels in Connecticut showed any hard-shell growth. The bad one was the Slick Barrier panel, which was liberally fouled with slipper limpet shells, locally known as "quarterdecks." The Latin name is crepidula fornicata, probably because when thickly settled they tend to mount up. When we checked with company president Ron Wilen to try to find the price, he told us that Slick Barrier is not, after all, on the market.

In Florida the fouling is always worse, and, as we noted, the Florida panels stayed in longer this year. There were a few barnacles and even bits of coral growth on a few of the Florida panels. If there were more than a couple of barnacles, the rating was lowered. Otherwise they were rated the same way, both at the extremes and relative to each other in the middle.

Paint Notes
Every year, when we try to draw firm conclusions from these ratings about hard versus ablative paint, or copper content, or biocides, we just about see a trend, and then find it undercut. For instance, this year we could say that, in Connecticut, the ablative paints seemed to fare better than the hard paints, and this would presumably be attributable to the strong tidal current at the floating dock. But there are too many exceptions for the rule to stick. There are also differences in paints that supposedly have the same copper content. This has happened regularly in these tests, and the paint makers tell us that the consistency and make-up of the other elements of the paint, from the epoxy matrixes to the coloring agents, can make a big difference in how the copper performs. Add in extra biocide/algicide mixes, and you can engineer a really effective brew, but one whose performance will be hard to predict from location to location.

After our evaluations of the 2001-2002 paints (reported in the April 2002 issue) we gave the Florida panels a quick scrub and put them back in the water. We took a look at them when we pulled the 2002-2003 panels, and although there are too many variables to permit direct comparisons, we can tell you that two coverings looked better than the rest after 17 months (with that scrub at 6 months): Pettit Ultima SR, an ablative paint with biocide, and Interlux Veridian, a slick, silicone-rubbery covering that has unfortunately been dropped from the Interlux line-up for bottom covering. It's still available in a clear version for outdrive protection (this is what we used for these 2003 evaluations). Interlux said the formulation was tricky and too expensive for the market as a bottom coating.

We're still impressed with the non-copper alternatives from E-Paint, EP-2000 and EP-ZO. This year the ablative ZO did better than the hard 2000, with only a faint tan-colored film showing on the Connecticut panel. The 2000 had a more pronounced tan-brown film on the Connecticut panel and a thicker, uniform filmy layer of growth in Florida that would have to be attacked with a scrub brush.

We were interested in the results of the Teflon-based Interlux products, VC-17m and VC-17m Extra. Both did excellently in the colder, faster Connecticut water, and poorly in Florida.

It's always good to see coatings like Super Shipbottom, AquaGard, CopperPoxy, and the new SeaLife 1000 mix it up with the big guys. The smaller companies have their loyal followers, and they hang in there admirably.

The California-based makers of SeaLife 1000 claim that their paint is not only non-ablative, but virtually non-toxic. It's "engineered not to leach its active ingredient, cuprous oxide, (39%)—or any biocides, pesticides, or other toxins—into the marine environment." According to Vice President Dan Kubic, tests done by T.R. Wilbury Laboratories show a very low leaching rate, although not nil. It's also supposed to last for five to six years.

It was a clash of the titans at the top again this year—Interlux and Kop-Coat (with their various names and ownerships) got 10 of the 13 Excellent ratings between them. Sea Hawk Paints did very well as a group, with two Excellents, and E-Paint got one with its Connecticut ZO panel.

There's no question about the overall winner—two-part Micron Optima from Interlux came out of the water in both locales looking as if it had just been painted on. Best Buys this year are Pettit Premium, which you can find for $50 per gallon (try www.shipstore.com) and Gloucester Sea Jacket from Interlux, at about $47.

Time, now, to gear up again. Happy painting. May your fouling season be mild, and your bottom bright.


Also With This Article
Click here to view "Value Guide: Bottom Paints 2003."

American Marine Coatings, 800/290-8836, www.copperpoxy.com
BoatU.S. (retail per West Marine), 800/BOATING, www.westmarine.com
E-Paint Company, 800/258-5998, www.epaint.net
Flexdel Corp., 888/353-9335, www.aquagard-boatpaint.com
Super Shipbottom, 800/466-7144, www.supershipbottom.com
Interlux Yacht Finishes, 800/468-7589, www.yachtpaint.com
Kop-Coat (Pettit, Woolsey), 800/221-4466, www.kop-coat.com
New Nautical Coatings, 800/528-0997, www.seahawkpaints.com
SeaLife Corp., 866/384-7736, www.sealifemarine.com
Slick Barrier, 800/327-3456, www.unitedenergycorp.net
West Marine, 800/BOATING, www.westmarine.com

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