Aluminium propeller

[Alexis]

Hello there,

I have bought a second hand yacht, and am preparing to put to the water shortly for the first time (first time for me with this boat).
She's equipped with a very basic 2 blade aluminium Volvo propeller, on a saildrive. She has been brushed down to bare metal.
Changing the propeller is not an option yet.

Question is: can I put to the water as it is or should I paint it and if it is the case, what with?

Important points:
- hull is fiberglass.
- boat will be sailing in freshwater (Lake Geneva)

Thanks for any tips,
Alexis

<hr width=100% size=1>

 

[Birdseye]

I doubt very much whether the prop is pure aluminium - I would have expected it to be aluminium bronze since pure allly is so soft. Looks very much the same but is much stronger and different in corrosion terms. It isnt an inferior alternative to the normal bronze.

I paint my al bronze prop - the paint is a form of insulation to minimise corrosion and it lasts surpruisingly well. Epoxy undercoat and twin pack poly top coat. But my prop is on an outdrive leg and spends most of its time out of the water. I have been told that cellulose is an alternative paint but havent used it myself.

Pure fresh water is an insulator, but it is unlikely that the lake is that pure. Nevertheless, it will be better corrosion wise than the sea. Personally, I would still paint the prop.

<hr width=100% size=1>this post is a personal opinion, and you should not base your actions on it.

 

[extravert]

I would paint it, but you must use the proper system for aluminum. Unfortunately this is expensive compared to the small area you will be painting, as the smallest tins that the various paints are supplied in are all far too big. For expert advice, contact one of the paint manufacturers. They have always been helpful to me when I have asked.

When I did my saildrive leg, I used etch primer, a paint for aluminum, and then an aluminum-safe antifoul (you may not need this, depends on growth rate in your area).

Although using the boat it fresh water, still use an anode. You can get anodes for fresh water. They are made of magnesium.

<hr width=100% size=1>One day, I want to be a real sailor. In the mean time I'll just keep tri-ing.

 

[snowleopard]

if you want to paint aluminium, start with zinc chromate primer, obtainable in spray cans from any outboard dealer. international also make a new antifoul for props and saildrive legs (tried to look on their website but it's a shambles).

<hr width=100% size=1>

 

[tom52]

I think I have the same Volvo saildrive/ prop combination as you.
It was originally coated with some type of rubbery substance which last year began to flake off.
I went back to bare metal and used a special aluminium primer then several coats of primacon and then three coats of Blakes Mille spray on antifoul for aluminium saildrives/stern drives.
It looked good when it went back in the water yesterday but I wont know if it is good until it comes out again in November !
Ain't boating exciting ( and expensive !)
Good luck

<hr width=100% size=1>

 

[scarlett]

I use the international product designed fro props, name forgotten. It is about £15 for a teacupful but it works in the Med. Nothing has ever grown on it and I am still on the orgional can after ten years.

<hr width=100% size=1>