Protection for aluminium prop on saildrive

[wizard]

On lifting the boat out I find that the last outer two inches of the two bladed prop are now exposed slightly corroded aluminium.
Just wondered if anyone can recommend something to protect the aluminium from corrosion?

 

[Swagman]

Sorry - never seen an aluminum prop on a saildrive but would assume an anode of some form must be fitted close by?
JOHN

 

[Birdseye]

I used to paint mine with epoxy undercoast and twin pack poly top coat. It used to last at least 2 seasons

 

[billmacfarlane]

Maybe someone can correct me here but I thought that a saildrive was made of aluminium and as a result there would be no need for an anode to protect a prop made of the same material.

 

[alienzdive]

There should be an anode running the entire way around the shaft between the sail drive and the prop, if there is a gap there it has fallen off. Otherwise it may have been painted and will require replacing or stripping back to zinc.

You need to paint the shaft with aluminium based antifoul (NOT COPPER) and follow manufacturers directions for preperation and undercoats etc.

 

[wizard]

I seem to have misled people here. What I was after was what paint to put on the propellor to protect it as clearly there was something there before as it is quite a thick edge where it has come off. Many thanks.

 

[John_Clarke]

I normally use a couple of coats of Primocon each winter on the parts where the aluminium is exposed.

This winter I filed some bevels on the trailing edges to stop the prop singing. As an experiment on these larger areas I have used epoxy resin on a bright aluminium surface then, before the resin gelled, I sanded it with aluminium oxide paper to remove the oxide layer which cannot reform as it is protected by liquid epoxy resin. I understand that this is standard practice in the aircraft industry to get a good bond with epoxy and aluminium.

Time will tell if this works in seawater!

 

[hairbox]

Hi just done mine like this rub down with emery cloth to remove any loose and flaking stuff, etch prime bare alloy, prime with primacon 2 coats, then 2 coats Trilux sorted !!!!!!!!!!