Sacrificial anodes

[Sequoiah1]

If this has been posted before then perhaps someone could point me in the right direction if not.................

This got raised on another forum and I am keen to see what the general or expert opinions might be on the use of sacrificial anodes on wooden boats. Ours is not kept on a marina if that has a bearing and is never connected to shorepower. Boat is copper fastened Iroko on Oak. Galvanised iron rudder straps and rudder tube, bronze shaft log and prop, s/s shaft. Mild steel keel bolts, cast iron keel.
Do I need anodes and if so where?

 

[Porthandbuoy]

Anodes are almost as contentious as anchors in these forums!

How old is your boat and has it ever had anodes fitted?
If the answer is pretty old and no, never, then why bother . . . . .

unless your boat has been re-engined or has had something replaced in a different material from before (thinking st/st propshaft for bronze), then a problem could arise.

Do you have a corrosion problem? Is your prop de-zincifying for example.

I fitted a new st/st propshaft to Mariposa, and although she had never been fitted with an anode I put one around the shaft to protect the prop. The prop is 56 years old and still "rings" when tapped. After nearly two years there is negligible deterioration of the anode, so perhaps it's not necessary after all.

 

[chrishelen]

I read somewhere that if you OVER protect a wooden boat with anodes the wood around the metal can turn soft.M.G Duff are the people to advise on this,they were very helpful when i needed to reanode a ship i was working on,the ship being in brakish water most of the time.try google.hope this helps. chris.

 

[LittleShip]

Some good info here.

http://www.classicmarine.co.uk/Articles/metals.htm

or have a look at the MG Duff site and there are some PDF files that you can print off

Tom

 

[Jwoods]

During a survey on my Falmouth Pilot, the surveyor advised me to disconnect the anode wires to the hull valves. I still have an anode connected to the engine. The previous system did not work too well as the sink drain valve had disintegrated (handle came off in my hand!) and the cockpit drain valves had stuck. So far no further problems........

 

[Sequoiah1]

Many thanks for the advice and info. Looks like I am going to have to do some more research and then jump in feet first.