Marine Growth on Propeller - what are my options?

Maritime Marketplace review

February 23, 2017

Letter From the Chairman

March 18, 2017

March 6, 2017

Marine Growth on Propeller – How clean is my running gear?

You’re at the slipyard and you see boats with their propellers and rudders covered with marine growth. Now you’re wondering – what does my propellor look like down there?

Do you know the tell-tale signs of a foul prop?

More vibration than there used to be when underway
Noticeably slower through the water
Using more fuel to go the same distance
You don’t want to look – it’s been a while!

A clean and freshly painted boat will slide through the water efficiently, but after just a few weeks tiny marine animals start to grow on the underside. Their presence reduces the smoothness of the hull which then can’t slide as efficiently through the water.

Slime and barnacles – marine growth – reduce the efficiency of your prop dramatically. This means that you are burning more fuel and achieving less speed.

Worse, marine growth on your propeller may cause excess vibration, putting extra stress on your running gear.

Like most problems with boats, the answer may be different for each boat. For example, using your boat regularly will help to keep the bottom cleaner. And some waterways have more marine growth than others.

So what are the options? Should I use propeller antifouling paint?

Water turbulence, high speed and vibration make running gear the most difficult underwater surface to coat.

Apart from storing your boat out of the water, you can:

Slip more frequently to clean your prop – which can get expensive, or
Protect your propeller to minimise marine growth.

But what do you use to protect your prop? Some owners swear by sheep lanolin, but it’s a short-lived solution – you’ll still be slipping frequently. Propeller antifouling paint is another answer, but it carries its own problems. It’s highly toxic to the environment and inflexible, so the vibration of running gear tends to crack and loosen the coating. A third way is gaining popularity world-wide – a slick coating that acts like Teflon in a frying pan. It’s called Propspeed and it works by making the protected surfaces too slippery for marineorganisms to get a firm grip. You can wipe them away with a soft cloth, or allow normal vibration and cavitation to shake them loose.

The manufacturers claim the product is effective for 1-2 years between applications. Propspeed is a specialised foul-releasing coating that does not poison marine organisms – it sheds them. It’s very flexible, so doesn’t separate like traditional anti-fouling treatments under vibration. It is recommended not just for propellors but also for your shafts, rudder, trim tabs.

” This is the most inexpensive repower you can do for your boat, to increase speed and performance.” – Propspeed

I’ve always used anti foul. What’s wrong with that?

The ‘metal’ used in some anti fouls can have a detrimental effect, accelerating electrolysis in salt water. Your propeller becomes the sacrificial anode instead of the zinc.
Antifoul is not flexible, but quickly cracks and falls off. In the propeller wash, vibration and ‘harmonics’ impact on props, shafts and rudders.
Anti-foul is a poison, toxic to the environment

OK – where can I get this stuff?

Propspeed has traditionally been applied by marine specialists, available at most marinas to apply this protection to your boat. Boat owners can now buy the coating off the shelf for DIY application. Propspeed recommends that owners who prefer to do their own maintenance read the instructions carefully and follow directions for a great result. There’s more information at the Propseed website: visit Propspeed

AWBF will be happy to hear from boats owners who use the coating. Stay tuned for future product reviews! Drop us a line at office@australianwoodenboatfestival.com.au

Tim Oxley contributes to AWBF News and ReviewMarineProducts.

Marine Growth on my Propeller – what are my options?

Maritime Marketplace review

Letter From the Chairman

Marine Growth on Propeller – How clean is my running gear?

So what are the options? Should I use propeller antifouling paint?

I’ve always used anti foul. What’s wrong with that?

OK – where can I get this stuff?

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