Propeller -- To Paint or Not to Paint? That is the Question.

[a64pilot]

Wooden boats used to be Cooper sheathed. They used copper to prevent worms from getting into the wood and copper was very malleable and easy to work.
Copper will have growth just as fast as anything else, unfortunately.

[Wotname]

Originally Posted by a64pilot

Wooden boats used to be Cooper sheathed. They used copper to prevent worms from getting into the wood and copper was very malleable and easy to work.
Copper will have growth just as fast as anything else, unfortunately.

Err, not quite...

Copper reacts with sea water to form cuprous oxide which does deter some marine growth.

After some time (weeks / months?) this degrades further to become cupric hydrochloride. Being unstable, this washes away and has no effect on marine growth.

But yes, it is not a great anti-fouling medium.

[a64pilot]

I’ve hung a piece of Cooper pipe in the water out of curiosity, it seems to get growth on it just as fast as the guppy zinc I had hung too. It was done out of curiosity.
Only thing I know that really works on props is to cover one with a black plastic bag if your going to be at anchor etc for awhile.
It may not have to be black, maybe just cutting off the water is enough?

[savoir]

The black bag will cut out the weed and reduce the barnacles quite a lot. Weed is a plant and needs a little sunlight so it can't grow inside a black bag. Barnacles need circulating water to feed and won't get that inside a bag but that bag doesn't have to be black.

[Rorzech]

Would a SS prop on a SS shaft help the dissimilar metals issue ? And what about painting then also? I have a paint made by 3M that is designed to be electrical insulating. (nothing to do with marine) Curious.