Skip to main content

How to: Beat the Barnacles

Do you antifoul your propeller? Looking around the yard where we keep our project boat, Ostara, the consensus seemed to be “no”. Most propellers showed the telltale signs of barnacle infestation, as indeed did our three-bladed Gori folding prop.

Do you antifoul your propeller? Looking around the yard where we keep our project boat, Ostara, the consensus seemed to be “no”. Most propellers showed the telltale signs of barnacle infestation, as indeed did our three-bladed Gori folding prop. Barnacles aren‘t just unsightly, they’ll affect your propeller’s performance.

A coat of bottom paint is one way to thwart the marine critters that like to attach themselves to your propeller blades. Usually, you’ll have to rough up the blades with sandpaper to provide a key for the paint to stick to and give the blades a coat of Primocon or similar primer. If you have a saildrive, you’ll have to use a copper-free antifouling paint to minimize the chances of galvanic corrosion.

Many owners just polish their props to a mirror shine in the hope that the barnacles will fail to gain a foothold; others smear on some kind of grease (diaper rash cream is popular) as a deterrent. In warmer waters, it’s no big deal to dive on your prop every so often and scrape the barnacles off, but up in frigid New England waters that’s not so appealing.

Of the various proprietary anti-barnacle compounds on the market, Pettit’s Zinc Coat Barnacle Barrier is inexpensive and has a good reputation. Forespar has a new goop called Lanocote Prop & Bottom Foul Release, based on its popular Lanocote anti-seize compound, which in turn is derived from sheep wool.

And then there is PropSpeed, a silicon-based coating from New Zealand that defies barnacles and other critters to get a toehold on its slick surface. It’s not cheap, but it has an excellent reputation. The makers aren’t saying what’s in PropSpeed, but it’s non-toxic and as green as such products can be. It was certainly worth a try, I thought.

First, I had to thoroughly roughen the propeller with 60 grit sandpaper to provide a key for the ensuing coatings. It hurt to scuff up such a beautiful piece of bronze, but it’ll be easy enough to bring it back to a polish down the road. I wiped the sanding dust off with MEK and let it dry.

Suitably gloved up and wearing safety goggles to protect the peepers from stray acid droplets, I brushed the product on, and then, following the instructions, wiped it off with a clean rag before it had a chance to dry. If you don’t want to splash out $99 for a half liter of this at West Marine, you can use acetone instead.

It took me five minutes to stir all the settled sediment—the active ingredients—into solution, then I shook the can thoroughly to ensure it was well mixed. I then mixed it with the hardener in a 4:1 proportion. Because I only had one prop to coat and there is enough primer for two or three, I used a separate mixing container and saved the remainder.

It looks blotchy, but this is apparently usual. The goal is to get a thin, uniform coat over the entire prop. As soon as you can touch the primer without it coming off on your finger, start painting on the clearcoat. This dries to a soft finish, unlike any paint I’ve used.

The clearcoat has dried to a soft, slightly sticky coating, unlike any paint I’ve used before. I’m looking forward to seeing how it holds up to a season in the frigid New England waters.

PropSpeed comes in various sizes—the 200ml kit I used retails for $199 and was enough to coat a pair of props the size of the folding three-bladed Gori on our project boat. You can use it on propshafts, through-hulls, and any other bare underwater metal.

Related

promo-2048x

Just Launched Mid-sized Cruisers

With so many manufacturers dreaming up bigger production boats, more and more mid-sized cruisers fall on the smaller end of their lines. However, “smaller” does not mean less, and the tricks for optimizing larger models have helped with squeezing more enjoyment into less LOA. As ...read more

05-DSC_0638

Charter: Lake Tahoe

A sail on Lake Tahoe has been on my bucket list since the day I first laid eyes on it, and come hell or high water, I decided I was going to someday charter a boat there. North America’s largest and deepest alpine lake, Tahoe sits at 6,225ft above sea level and straddles the ...read more

East-River-Rapids

Escape from New York Part 1

I was never supposed to take my boat through New York City. After getting sucked backward through the Cape Cod Canal on my way south from Maine, when the speed of the current exceeded the maximum speed of my little electric auxiliary, I wanted nothing to do with Hell Gate and ...read more

LEAD-Celeste-in-the-Tuamotu

A Watermaker Upgrade

As a classic-boat sailor, I’ve long held that simpler is the better. I still think this is true: a simpler boat is cheaper, she has less gadgets to break down and there’s a certain satisfaction in knowing you’re able to handle a bit of discomfort. Thus, for a long time, I sailed ...read more

01-LEAD-IDECsport_180919_032

Sailing Speed Records

Although the 1903 defender of the America’s Cup, Reliance, was deemed a “racing freak”—the boat pushed design rules to their limit and couldn’t be beaten, at least in very specific conditions—designer Nat Herreshoff was nonetheless onto something. A century later, purpose-built ...read more

BVIFeetup

Chartering with Non-sailors

Three tips on managing the madness First-time charterers and first-time sailors aren’t at all the same thing. One group may struggle with beginner chartering issues, like sailing a multihull, catching a mooring or dealing with base personnel. For the other group, though, ...read more

AdobeStock_455372159

A Gulf Stream Crossing at Night

Even the dome of light glowing above the city behind us had disappeared as if swallowed in a gulp by Noah’s whale. The moon was absent. Not a star twinkled overhead. The night was so dark we could have been floating in a pot of black ink. The only artificial lights to be seen ...read more

00-Lead-549215sJL2uLEa

Summer Sailing Programs

Every year, countless parents find themselves navigating the do’s and don’ts of enrolling their children in a summer learn-to-sail program for the first time. While the prospect of getting your kid on the water is exciting, as a sailing camp program director, there are a lot of ...read more