Anode mounting studs

[Ardenfour]

I want to fit a larger anode on the keel but the existing studs are too short, and due for resealing anyway. Should I replace with mild steel or stainless?

 

[neil_s]

In theory, mild steel is OK - protected by the anode. In practice, I find they rust inside the boat and get messy. I use stainless, now.

 

[superheat6k]

Stainless is prone to crevice corrosion where it passes through the hull. Using mild steel is OK because the first thing the anode protects is its mounting studs. Normally they are supplied galvanised.

 

[Tranona]

Is this on a steel or iron keel? If so why are you fitting an anode at all?

 

[Stemar]

This should do the job, assuming a GRP or wooden hull

M G Duff M10B Anode Fixing Stud Assembly | Force 4 Chandlery

 

[Ardenfour]

Is this on a steel or iron keel? If so why are you fitting an anode at all?

It's a long keel grp. Anode is wired to Mercedes engine which doesn't have any internal anodes

 

[Tranona]

It's a long keel grp. Anode is wired to Mercedes engine which doesn't have any internal anodes

OK - but it won't do anything to "protect" the engine as the anode is in the external seawater, not in the engine cooling system. The engine probably does not need one anyway otherwise the maker would have fitted one. They are usually in the heat exchanger of a freshwater cooled engine or in the block of a seawater cooled type.

However it may well be connected via the engine and gearbox to the prop shaft to protect the propeller from the shaft. If this is the case you should check for continuity between the anode and the propeller. Presumably if you want a bigger anode - what type is it? - it is doing something so it is best to check out exactly what it is protecting. If it is the propeller then it needs to be sited close to it, less than 1m if possible.

 

[Ardenfour]

OK - but it won't do anything to "protect" the engine as the anode is in the external seawater, not in the engine cooling system. The engine probably does not need one anyway otherwise the maker would have fitted one. They are usually in the heat exchanger of a freshwater cooled engine or in the block of a seawater cooled type.

However it may well be connected via the engine and gearbox to the prop shaft to protect the propeller from the shaft. If this is the case you should check for continuity between the anode and the propeller. Presumably if you want a bigger anode - what type is it? - it is doing something so it is best to check out exactly what it is protecting. If it is the propeller then it needs to be sited close to it, less than 1m if possible.

Ok, thanks. I'll check what's going on.