Anodes and rust etc

[noname]

I have an "IP24" which is a project boat i will be putting back in to the water in march,i have read a few posts regarding the fitting of anodes and would appreciate hearing of your experiences .
My boat has two large steel bilge plates and a keel,also rear lower keel extension and steel rudder.
The boat had about two feet of water in the bilges when purchased last year, and had as a result eaten the aluminium water pump pulley and caused severe damage to the gearbox casings.
Having now fitted a replacement box and repairing or replacing other damaged parts,i am eager to slow or hopefully stop any further damage.
Needless to say the water in the bilges was a big part of the problem before, but with so much metal below i would appreciate useful advice to protect it in future.
Should all engine gearbox components be linked with a cable to electrically connect them together,if anodes are to be fitted should i connect the steel items where possible together.
On my last boat a Sabre 27 the surveyor stated that all Sea cocks and skin fittings should be connected,i have read on here somewhere that only similar metals should be!
confused!! many thanks.

 

[VicS]

All components to be protected by anodes must have anodes nearby connected to them. The keel, the bilge plates the rudder will all need anodes each side of them. Maybe anodes should be bolted directly to them or mounted on studs welded to them although you may be able to economise on the number of anodes by fitting hull anodes and wiring them to the fixings

The connection of the engine or gearbox to an anode is usually to protect the stern gear, if necessary, with an anode close to it, but flexible couplings must be bridged to complete the electrical connection. Interconnection of all hull mounted anodes would probably be wise. If you have a shorepower system the earth should also be connected along with the 12 volt negative ( this is the accepted practice to conform with EN ISO 13297 for boats built to CE or ABYC standards)

Bronze or DZR skin fittings should not need cathodic protection by separate anodes although ordinary brass might until replaced by a more suitable material.
One of the recommendations in the MAIB report into the flooding of the FV Random Harvest off Brighton on 3 July 1999 was that all through hull fittings should be disconnected from the vessels cathodic protection system.

Worth reading MGDuff's website You'll find a recommended wire size there for connecting anodes.

Random Harvest See paragraph 2.5