Replacing anodes what to bond

[Lundylad]

I am about to replace the anodes on my newly aquired boat.

Simple enough job remove old ones, clean area to ensure good bonds to the keels and ensure that the bonding connections to the keel bolts is good and the same for what they are bonded to.

Question is what needs to be bonded, Engine obviously, seacocks?.
Having Googled it and read through previous posts on here it the subject seems to divide opinions.

Is it simply anthing below the water line that has a direct or indirect contact with water.

 

[mithril]

Oh dear - go slowly on this one. Dont go willy nilly bonding everything in sight. Modern boats dont bond anything and dont use anodes except directly on saildrives, prop-shafts and props.

So do you need a new anode, is it erroding, what is it currently connected to, are any of the skin fittings showing signs of aging? If its a newish boat go with what the manufacturers originally did.

 

[VicS]

I am about to replace the anodes on my newly aquired boat.

Simple enough job remove old ones, clean area to ensure good bonds to the keels and ensure that the bonding connections to the keel bolts is good and the same for what they are bonded to.

Question is what needs to be bonded, Engine obviously, seacocks?.
Having Googled it and read through previous posts on here it the subject seems to divide opinions.

Is it simply anthing below the water line that has a direct or indirect contact with water.

Bond only the items that need protection

Bronze or DZR skinfittings and seacocks should not need protection.

Do not bond non-ferrous items to the same anode(s) as ferrous items.

The engine is protected by its internal anode(s) A hull anode offers no protection to the engine,

The engine may be bonded to a hull anode in order to protect the stern gear BUT any flexible coupling must be bridged to complete the circuit. The connection through the gears and bearings may still be poor.

Anodes must be near to and "within line of sight" of the items they are to protect.

Dont fix what is not broken. If they are no signs that anything needs additional protection it probably doesn't.

 

[Jcorstorphine]

I have the same problem.

Up until last year my boat was only in for about 4 months and I never bothered with Anodes. However last year it was in the sea for 7 months and my prop is showing signs of electrolysis. My antifouling was SEAGO copper (something)

The mixture I have is a stainless rudder, a bronze shaft, bronze stern tube and a NIBRAL propeller. The engine seacock appears ok as does the toilet seacock so I was planning to bond the rudder, the stern tube and the prop shaft which include the engine (fresh water cooled) to the anode.

The anode would be placed close to the rudder if not actually on the rudder itself and the others tied to it. The reason I am worried is that I may need to fork out a fortune on a new prop and don’t want it to end up as a pile of lace.

J.

PS I painted the prop with the SEAGO copper antifouling ( was this wise)

 

[VicS]

a bronze shaft, bronze stern tube and a NIBRAL propeller

Should not cause any problems

NIBRAL is very corrosion resistant and more cathodic than tin bronze ( by a small margin)

If bonded to a stainless steel rudder maybe a problem but the NIBRAL should be the last to be affected.

Very odd and I think I would be looking for some explanation other than galvanic corrosion due to those metals.

Shorepower ?? galvanic isolator ??


I'd not bond the rudder to it in fact I'd check to make sure there is no connection deliberate or otherwise.

If it comes down to fitting an anode I'd use a shaft anode if possible.

 

[Lundylad]

Thanks for the replies and yes will be taking it steady.

The boat is is a Jaguar 27 with a saildrive and the saildrive anode looks fairly new and as I am told that the saildrive has been serviced recently I will assume so but keep an eye on it to make sure it is working.

The anodes on the keels have been working well and the engine anode is new.

Will be replacing the bonding cables as I want to know they are ok and will be replacing a lot of the wiring as it is in need of it.

 

[ghostlymoron]

I removed the anodes completely as I was fed up with bashing my head on them everytime I anti-fouled between the keels. If you're on an open mooring, they're not any use anyway. If I had been based in a marina with stray voltages, I wouldn't have been so cavalier.

 

[Tranona]

Thanks for the replies and yes will be taking it steady.

The boat is is a Jaguar 27 with a saildrive and the saildrive anode looks fairly new and as I am told that the saildrive has been serviced recently I will assume so but keep an eye on it to make sure it is working.

The anodes on the keels have been working well and the engine anode is new.

Will be replacing the bonding cables as I want to know they are ok and will be replacing a lot of the wiring as it is in need of it.

What are the bonding cables doing? The saildrive anode protects the drive which is isolated electrically from the engine. The engine anode will be in the heat exchanger. Assume the keels are cast iron, so anodes will really do little for them as they are not connected to any other metal. It is not normally necessary to bond any skin fittings in a GRP boat, so really cannot see any need for anodes.