- Propspeed Marine Antifouling Propeller Coating - Photo by Jane M. Anderson
Boaters who dock or moor their vessels in warmer waters soon will find that a clean, polished propeller -- fresh from the boatyard and free of any blemishes -- will become a mini-ecosystem of marine life within just a couple of weeks if they fail to protect it.
Even boaters in cooler waters aren't immune to marine growth on bare metal -- it just takes longer for the barnacles, moss and oysters to take up residence. Using the boat frequently can help keep the growth down, but most recreational boaters just don't have time to use their boats often enough to keep their props clear.
For unsuspecting boaters, the first sign that their prop has become a solid mass of marine growth comes when they attempt to pull out of the slip and find that their boat has less power and maneuverability than expected. At that point, the only remedy is to dive on the prop to scrape it clean, or to hire a diver.
Fortunately, several different bottom paint coatings suitable for metal surfaces are available that promise good to excellent results at keeping propellers and other underwater metal surfaces clear of growth. Boat owners have reported decent results with Propspeed, Prop-Shield, and Pettit Paint's transducer paint.
Propspeed: Slick Bottom Paint Finish for Props
Propspeed propeller coating is a two-part, gold-colored coating that doesn't include poisons such as copper; instead, the coating creates a surface that's so slick, barnacles and other marine growth cannot attach themselves to it. Product distributor Propspeed USA claims up to 10 percent greater fuel efficiency and up to an additional three knots of boat speed for vessels equipped with its prop coating.
The product isn't cheap: A 200ml kit (enough to coat two medium-sized powerboat props or several sailboat props) costs $169.95 at several online marine retailers, while a 500ml kit costs $269.95. However, partially-used kits should remain usable until the next boating season, one distributor said.
Application of Propspeed is tricky; proper application is key to Propspeed antifouling paint success. Although the company recommends hiring a certified applicator to apply the product, skilled do-it-yourself boat owners -- especially those accustomed to working with two-part epoxies and paints -- can apply it themselves with careful attention to the product's directions.
Propspeed can last up to two years, although one year of antifouling protection is more common, especially in warmer waters.
Prop-Shield Uses Lanolin Base to Protect Underwater Metal
Prop-Shield, manufactured in the United Kingdom, is another non-toxic product designed to prevent both marine growth such as barnacles plus electrolysis, a corrosion problem that results from minute electrical currents between dissimilar metals (such as bronze and stainless steel) underwater.
Many thrifty boaters have smeared copious amounts of anhydrous lanolin (a byproduct of wool production) or even off-the-shelf Vasoline on their running gear as antifouling protection, with mixed success; boaters in cooler waters seem to do better with these products.
Prop-Shield is made with lanolin derivatives plus other non-toxic chemicals, and the company promises up to 12 months of protection.
Prop-Shield adheres to bronze, stainless steel, aluminum, Zytel, and painted surfaces, the company says. A 6-ounce container costs $59.95 through the company's website, and will treat the props and shafts on a 40-foot twin-screw boat once, the company says.
Pettit Transducer Paint Not Just for Transducer Antifouling
Pettit Paint offers a zinc-based transducer paint, and some boaters say the product is suitable not just for transducers, but for coating propellers and other underwater bare metal surfaces as well. The paint is designed as an anti-corrosion paint but also works as antifouling, according to some boaters.
The silver-colored paint, which contains 93 percent zinc, comes in a spray can. According to the company, it's designed for use on plastic transducer housings plus bare metals such as steel, stainless steel, cast iron, copper, bronze, galvanized steel and lead.
A Chesapeake Bay-based boater reported on Woodenboat Forum that he has used Pettit Paint's transducer product on his props for five years, and it keeps the metal clear of growth all season. One can will paint six props, he said.
According to Pettit Paints, the hard surface of the transducer paint will prevent growth and scrub itself clean as the boat moves. A 16-ounce spray can of Pettit transducer paint costs around $20.
Antifouling paints for props can help keep marine growth down, which can improve vessel performance. Boaters have a variety of antifouling choices for their propellers and other running gear.
Jane Anderson - Jane M. Anderson spends as much time as possible on the water, working and sailing on boats. She grew up sailing Sunfish and Rhodes 19s on ...
