Paints

When we last reported on bottom paint, several manufacturers were introducing new copper-free paints in response to increased pressure from environmental groups and regulatory agencies. Another key trend is a move toward water-based paints with a low VOC. At this point in our tests, results are mixed with many of our newest paints. A full Value Guide detailing the performance of almost 30 new paints at four months; over 50 hard and ablative paints at 14 months; and close to 20 hard and ablative paints at 30 months is included in this month’s report. Paints from Blue Water, Epaints, Pettit, Interlux, and Sea Hawk continue to do well. Find out which ones are top rated for racing sailboats, aluminum hulls, cruising boats, and environmental friendliness.

Determining how much faster a boat can sail with one paint versus another would be difficult as the prep and application of both paints would have to be identical, as would test conditions, in order to have a fair trial. None of the antifouling manufacturers we spoke with are aware of any documented head-to-head speed tests of paints.

Boat owners looking to put some stick back into a slip-and-slide deck have a few options: apply a deck paint with a nonskid additive or glue sections of specialized nonskid mat to the deck. Choosing which type of nonskid is the right one for your boat makeover is a balancing act between aesthetic taste, traction needs, and budget. Practical Sailor tested 11 commercially available nonskid options that the average boat owner can easily apply: one paint with no filler media, five paints ready mixed with nonskid compounds, three nonskid additives that testers mixed with two-part topside paints, and two nonskid mats (one is self-adhesive, and one is glued on with an epoxy). All of the products can be applied to fiberglass, wood, or metal. Manufacturers included Pettit (Kop- Coat), Epifanes, AkzoNobel (Interlux and Awlgrip), West Marine, Pachena (KiwiGrip), Durabak, Tiflex (Treadmaster), and SeaDek. Using some creative bench tests, we evaluated how much traction, grip, and drag resistance each offered; we also rated how easy the products were to apply, how uniform the grit was, and how easy they were to clean.

A good DIY nonskid offers effective traction (obviously) and is easy to apply, easy to clean, durable, and gentle enough on knees and elbows that a foredeck monkey won’t leave blood stains behind. Testers focused on these criteria during bench testing, and when considering final ratings, we weighed the results according to their importance. For example, a product that had great grip but was hard to clean rated better overall than one that was easy to clean but offered no traction. This was a fairly close race, so we used a plus-minus system in the ratings (see accompanying Value Guide)—something we don’t often do—as every point mattered.

Although we’ve tackled our share of varnish with a heat gun and scraper, we’ve never used them to strip bottom paint. The obvious concerns would be marring the gelcoat and the noxious fumes created by heating paint solvents and active ingredients. Our first choice for removing antifouling would be sodablasting (PS, October 2011), but as that’s not an option for you, we’d consider chemical stripping (PS, April 2008 and March 2009), wet-sanding, or vacuum sanding.

In July 2009, 61 samples of antifouling paints, including several new formulas, went into the water in Sarasota, Fla., for testing. This report and the tables above offer a 24-month update on our findings on the top paints in that field, which we last reported on in April of 2011. For sailors who value longevity over all other factors, that article, along with this report on paints that rated a Fair or better after 24 months, will serve as your best guide to choosing a long-lasting bottom paint.

Practical Sailor continues its search for the best antifouling as we test a large field of bottom paints, including products from Pettit, Blue Water, Epaint, Interlux, and Sea Hawk. In this report, we rate the paints' eight-month and two-year performances. Some budget-friendly and eco-firnedly paints were still doing quite well after a season in the drink. When we last checked in on bottom paints in the March 2011 report, the ban on copper in antifouling paints was on the docket in Washington state and California. As the movement to ban copper moves eastward, the bottom paint industry is in flux, with manufacturers reducing the amount of copper in bottom paint and trying new copper-free paints. Bottom paint will probably not decrease in price, or increase in effectiveness, in the next few years.

The paint samples were applied to 6-foot-by-2-foot fiberglass panels for testing. Testers follow the makers’ instructions for preparation and application. There were 11 samples per test panel. All but four samples had two coats of paint.

Last November, we began field trials of Mussel Buster, a baked-on powder coating that relies on its slick, hard coating to prevent barnacles from adhering. After six months, the prop was surprisingly clean. A few small barnacles had appeared, but they wiped away easily with the sweep of a hand.

When deciding on a process for clearing antifouling paint and coatings off the bottom of your boat, first define your goals and try to be as minimally invasive as possible. If your boat bottom needs more than a scrubbing but less than a full peel, sodablasting is a technique that will strip bottom paint but leave gelcoat intact. The unique softness of the calcium carbonate powder in sodablasting is effective, and the tented setup keeps the old coating contained. This report outlines the sodablasting process, calculates the cost in time and money, and compares its performance and cost-effectiveness to other bottom-stripping techniques we've tested.