Keeping Barnacles Off Your Propeller

Having been plagued by barnacles and other intrusive organisms for generations, the sailing community has brought the full breadth of its considerable inventiveness to bear on this sticky problem.
Author:
Updated:
Original:

From the moment we left the mooring, I knew what was wrong. The boat had sat, hardly used, for nearly a month; now, as I opened the throttle, the engine note changed to a complaining rattle, black smoke belched from the exhaust, and the boat moved reluctantly off as if tethered to the bottom by an elastic band. From past experience, I knew the propeller was covered in barnacles. The only bright note was that it was late October and we were taking the boat to be hauled out, so there would be no plunging into frigid New England waters to scrape the growth off the prop.

The problem of keeping your prop barnacle-free is by no means restricted to the Northeast. From the Florida Keys to the Bering Strait, those pesky arthropods alight gleefully upon your running gear and settle down for the long haul. And in another example of life’s little injustices, they affect us sailors more than they do powerboaters. The more you use your engine, the less likely you are to have your prop colonized by barnacles.

Having been plagued by barnacles and other intrusive organisms for generations, the sailing community has brought the full breadth of its considerable inventiveness to bear on this sticky problem. You’ll hear barroom tales of the efficacy of potions of waterproof grease mixed with cayenne pepper, tetracycline and even quinine powder; some swear that rubbing a black magic marker onto the propeller blades keeps growth away; and others hold forth about the growth-repellent properties of lanolin. All of these, according to the anecdote, have worked for some sailors in some waters at least some of the time. Just as with any bottom paint, though, there are many variables affecting the way your prop potions work—temperature, salinity, vessel movement, currents, sunlight.

And therein lies the twofold problem with propeller fouling. There is no clear consensus as to what works best in any given scenario, and even if something does work, how well will it adhere to a spinning propeller? Many different approaches have been tried: here are some of them.

Nothing at all: Some sailors polish their props to a mirror gleam and leave it at that, trusting the slick surface will offer no toehold to inquisitive barnacles. It seems to work sometimes; but often it does not. It never has for me.

Rub-on coatings: Some boat owners report that an easily applied polish like Sex Wax, beloved of surfers everywhere, works well and can be reapplied underwater. Diaper rash cream containing zinc oxide also has its, er, adherents. The case for magic marker is not convincing; if anyone has more than anecdotal evidence regarding this, please let me know. Lanolin—which keeps sheep from becoming waterlogged—also has its fans, and an effective proprietary compound called LanoCote, marketed as a propeller antifoulant, is available on the U.S. market.
[advertisement]

Antifouling paint: Bearing in mind that you should not use copper-based AF if your boat has a saildrive leg, this seems to be as an effective a method as any, and perhaps better than most. The trick is to sand your precious prop, and then apply an epoxy tie coat before two or three topcoats of regular bottom paint. I’ve found this lasts the best part of a season. Many don’t even worry about the tie coat, just slapping the bottom paint directly onto the bare metal, but I think it sticks better with a tie coat. If galvanic corrosion is a concern, try one of the copper-free products like Trilux or Velox Plus, a new paint developed specifically for running gear and outdrives.

Other products: Many have had success with zinc-based coatings like Pettit’s spray-on Prop Coat Barnacle Barrier, or even hardware-store cold galvanizing sprays. McLube’s Antifoul Alternative Speed Polish kept my propeller clean for 10 weeks but then wore off, resulting in the spectacular barnacle collection seen on the opening page. Probably the best of the alternative products—and certainly the most expensive—is Propspeed, a silicon-based compound that requires meticulous care in application but will last two or three seasons if properly done. I found this the most effective product I’ve used so far. Another thing I’ve learned—read the maker’s instructions, and follow them to the letter. If you take short cuts with any of these products, they won’t work as advertised.

Then there’s the ultimate solution—a black plastic bag pulled over your prop and held shut with a rubber band. If you have to leave your boat for an extended period, this is a fine way to keep the propeller barnacle-free—just don’t forget to remove the bag before you motor off on your return. To get around this embarrassing possibility, one enterprising chap has come up with the PropPak, a reusable plastic bag that can be removed from the cockpit.
[advertisement]
Finally, don’t neglect your propshaft. Coat that too, but leave the metal under the shaft anodes bare, and—I can’t believe I’m writing this—do not paint over your zincs. One tip I saw online somewhere sounded interesting—wrap a couple of layers of masking tape around the propshaft, then apply a couple of coats of bottom paint over the tape. At haulout time, just slit the tape with a razor blade and peel it off to expose a shiny shaft that needs no cleaning. Another old wives’ tale? It wouldn’t be the first…

RESOURCES

Barnacle Barrier

Pettit Paint pettitpaint.com

LanoCote

Forespar forespar.com

Propspeed

Propspeed propspeedusa.com

Trilux

Interlux yachtpaint.com

Velox Plus

PYI Inc antifoulingpaint.net

Related

09-Map-Route-VG2020

Vendee Globe Village Closing, Race Still On

Following the latest national lockdown measures announced by French President Emmanuel Macron as part of the fight against Covid-19, the 2020-21 Vendée Globe Race Village will be closed to the public beginning Friday, October 30th. The Vendée Globe will still take place as ...read more

Register-2048

Register of Circumnavigators Launched

Just in time for a fresh class of Vendée Globe sailors to attempt their circumnavigations, The International Association of Cape Horners (IACH) has taken on the responsibility of maintaining an official register of sailors who have completed solo circumnavigations by the Three ...read more

FPO skys0tlm8jlrpynehcpe_NEW

A Half-century of Cruising with SAIL

I cannot say I have been reading SAIL magazine since the very beginning, but I come pretty darned close. Sometime around 1974, when I was in high school, I began buying it every month at our local newsstand and saving every issue until I had great stacks of them, as carefully ...read more

B&G-Halo20+-side-facing

Gear: B&G HALO radar

B&G’s HALO series of radars now includes the HALO20+ and the HALO20, a pair of compact radomes expressly designed for use aboard smaller sailboats. The units measure 20in in diameter and weigh a mere 11lb. The HALO20+, in particular, delivers a full 360-degree sweep every ...read more

PICTON CASTLE under sail with stunsls WV7 compressed

Picton Castle Seeks Crew

The Picton Castle is set to begin its eighth circumnavigation this spring under the command of Captain Daniel Moreland. A professional crew of 12 will guide up to 40 trainees at a time as they learn about all aspects of sailing the bark, from steering to lookout, ...read more

DSC_0013

Ask Sail: Keel Attachments

Q: I have an early ‘70s Catalina 27. The keel bolts look pretty good. My question is, why not glass over the keel to bond to the hull rather than changing the bolts if, or when the bolts are too far gone? I haven’t seen anything on this, so could you discuss? Full-keels are ...read more

04-GOPR0511

Book Review: Sailing Into Oblivion

Sailing Into Oblivion by Jerome Rand $15.99, available through Amazon As refreshing and inspiring as Jerome Rand’s 2017-18 solo-circumnavigation may have been, his account of the voyage in the book Sailing Into Oblivion: The Solo Non-Stop Voyage of the Mighty Sparrow may be even ...read more

01-1970-Dec

50 Years of SAIL

Back in early 1970, Bernie Goldhirsh and the recently founded “Institute for the Advancement of Sailing,” publisher of an annual sailboat and gear guide, launched something called SAIL. A half-century later, a look back at the magazine’s first few years provides a glimpse into a ...read more