That story from SirJman re loss of power reminded me to share my experience with folding props.

I usually sit at a Gold Coast or Brisbane marina during the cyclone season. Last year , after 4 months not moving , at Gold Coast. Set out for Cato Island in light conditions. Fair bit of motoring , especially to clear the East Australian current. It was soon obvious that engine temps were up , increasing revs. didn't produce the speed expected.
I run a pair of Gori's on the Yanmars. The Prop Speed was less than a year old. Anyhow , a look over the side and I could see that the props were not fully engaging. Diverted to Frazer and put her on the beach. Sure enough , barnacles in the gear mechanism and some fouling on the props.

Spoke to Gori and to Propspeed . It seemed that the only solution is to run the props each week , just to engage fwd. reverse and stop. The other option is to dive and put light bags over the folded props. Made up the bags but this year , ended up at Rivergate Marina . Needed courage to dive here, so now are spinning each week!

After 2 months , spent a weekend at Koonangai, nice ,clean water! The props had a few barnacles but the gears were clean and shiney.

I do wonder if there is a alternative solution. There would be a lot of boats where the skipper can't run the props every week ?

I have been told by numerous people that prop speed does require the props to be turned about every 2 weeks. Makes sense to get the film off the prop before it takes hold through the coating.

Propspeed protects the blades pretty well, but it will quickly wear off the actual gears on a folding prop. Then there's nothing to stop the barnacles, so 2 weekly exercise sounds about right.

I agree SeaDragon , it is a real hassle ! I think that these super efficient geared props have a big downside. Most boats, stand still for most of their life.

My old Crowther had fixed props and the efficiency just gradually diminished .QLD cruiser, you have summed up the problem- Propspeed clearly wears off the gears and creates a dangerous situation , at least it would be a big problem for a power craft !

Next time I slip or dry out i'll try a coating of Lanolin , the NZ genuine stuff if I can source it.

Ramona said..

Some people swear by a good metal etch primer followed by a hard antifouling.

I think that is as about as good as it gets.

MorningBird said..

I did the etch primer and hard anti foul. Lasts about 20 hours motoring and you have the same problem with the gears.

I now use prop speed. My issue with prop speed is the stuff is so thick it can make the gears/opening faces sticky even without any barnacles. Needs a burst of power to get them to open which is a pain with the vibration from the prop. The stuff lasts on the blades for 18 months on my boat.

Doing it yourself and have access to the product? Down here its only applied by experts at $450 a prop!

Regarding Propspeed- I picked up a tip on a blog , last year . Clean and polish the prop and apply a few coats of Cabots CFP floor finish, Gloss .This is an Acrylic.

I have tried it on one prop and after a year , can see no difference to Propspeed. Still minor barnacles . Costs bugger all at Bunnings.

Ramona, what gear do you use when polishing the prop? wet and dry then buff with a drill?

claverton said..

Ramona, what gear do you use when polishing the prop? wet and dry then buff with a drill?

I just linish with a blunt fine sanding disc on a mini grinder.