Pros and Cons: Painting Rudder and Prop

[Elizabeth Ann]

Hi All:

Last year we had an incredible amount of growth on our tabs, rudder, and prop which we discovered when we winter hauled her.

That was our first year with the Albin and it was made ready by the marina where the boat was stored. They didn't paint these items.

I know I can paint the trim tabs leaving some exposed meal for the zinc placement, but what about the rudder and prop (the prop is brass I think)?

Are there any advantages / disadvantages to painting the rudder and prop to prevent growth?

Cheers!

[AlMar]

I don't see how it can hurt. We alwayes use the leftover paint to put an extra coat on the waterline, and do the running gear. Since we dive, we can see it doesn't last long, and it does help a bit on the trimtab tops.
AlMar

[DougSea]

Almar - do you paint the prop? My rudder and tabs are painted but the prop was not. I'd imagine I'd have to use a more specialized paint for the prop given it's a 'high-speed' component.

[chiefrcd]

I think a lot has to do with splash time vs bloom time and how much you use your boat. For example, I have always painted my bottom in early April and splashed in mid month. Here in Deltaville there seems to be real serious barnicle growth in late April through early June. If I spash my boat and don't run it much during that two month period I will get significant growth on those non-painted areas. If I use my boat during that time, I get little to no growth. So, for me, if I know I'm going to use my boat a lot, I don't worry too much about painting the running gear, but If weather or work prevent lots of use, it's better for me to paint the gear and at least have some protection while the boat sits. Once up and running during the summer, neither paint or barnicles seem to last on the running gear.

[tomcat rio]

...

...
http://www.mesa.edu.au/friends/seashores/barnacles.html

[DougSea]

A brief writeup on prop fit and painting:

http://www.propscanusa.com/propeller_checklist.htm

[Mariner]

DO NOT paint the metal parts of the boat with traditional bottom paint. Doing so will speed corrosion of the parts. It has to do with the varying nobility of the metal parts and the metal in the paint. BAD IDEA.

I have seen many corroded lower units and propellers as proof. I have one sitting out in my garage.

They do sell clear anti-fouling paint designed for metal parts to be used in conjunction with traditional bottom paint. But it's effects are not lasting and it does not prevent all growth. Still, it's worth doing.

[AlMar]

We have painted the prop. We've used a zinc chromate primer, we've painted it unprimed, and we've used just zinc primer. All are fairly unsuccesful unless the boat is going to have very little early use. Once we get about 20 hours underway, most of it has spun off. I searched for problems using bottom paint on props, and most said the props are fine but not to paint the shaft. We used a hard bottom paint this year, so I'll have an update when the water warms up enough to go under. I'd be interested in where Mariner got his info, as I've been doing this for many years on different varieties of boats with no noticeable corrosion. Do NOT put copper paint on aluminum. That may account for the outdrive issue.
AlMar

[Russell]

Pettit 1793 transducer paint is a good choice for the prop if you do not use your boat often enough to keep the barnacles from growing. It is intended for metals and is a spray. As I understand it, the larval form of the barnacle swims around and attaches weakly to a surface and tests the food supply. If the conditions are not right they can detach. If everthing is fine they secrete their permanent cement that makes them so hard to remove. So if you use your boat often you probably detach them mechanically before they put down their permanent cement.
A few years ago I read on the Cape Dory site a report that metal stove polish would prevent barnacles from growing on the propeller. The person swore that it worked. I had my doubts but since it was only $6 at the hardware store I thought what the heck. The yard manager asked what I was putting on and laughed when I showed him the bottle. I watched the web site and a few months later someone complained that they tried it and it did not work. Another person suggested that it wore off. The orginal user then logged on to say Not true, I used my boat almost every day and it worked fine all season. I just laughed.

[Elizabeth Ann]

There seems to be too much debate. I think I may just leave it bare.

Cheers.

[bnoft]

We have painted the running gear in the past but this year the yard owner wanted to try a "new" product from a company in the Research Triangle Park in NC. I don't remember the name but it has very strong adhesion (1000 psi) on the dry cured side and is like a wax on the wet side, sort of a waxy teflon (Dupont might object to my use of their trademark). Will have to wait til August to see the results but it looks promising.