Interesting anode story - well for me anyway!

[Mike k]

Just come out of the water for annual antifoul and new anodes. In the boat yard I
I was aked if I am permanently connected to electricity on the pontoon because my anodes( 12 months old are pretty corroded).No was my reply as I dont use much electricity and only for a couple of weeks during the cold spell to get the tube heater ticking over.Thats strange was the reply where are you moored - next to a huge steel house boat I replied- aah thats the reason for the anode depreciation I was told!! On a positive note they have protected all my metal work perfectly well but i found the comment interesting.

I find cathodic protection an interesting yet still not undestandable concept hence my over cautious anoding with one on each trim tab, one on the rudder, one on the transom with wires everywhere and an electro eliminator on the prop shaft. I have asked for one to be fitted on the bowthruster ( 25 kgf) but i am at a total loss how that will be fitted because I cannot find any fitting instructions anywhere. So this post is a bit of info for comment and a question about bowthruster anode fitting .Thanks for any responses Mike

 

[VicS]

Just come out of the water for annual antifoul and new anodes. In the boat yard I
I was aked if I am permanently connected to electricity on the pontoon because my anodes( 12 months old are pretty corroded).No was my reply as I dont use much electricity and only for a couple of weeks during the cold spell to get the tube heater ticking over.Thats strange was the reply where are you moored - next to a huge steel house boat I replied- aah thats the reason for the anode depreciation I was told!! On a positive note they have protected all my metal work perfectly well but i found the comment interesting.

I find cathodic protection an interesting yet still not undestandable concept hence my over cautious anoding with one on each trim tab, one on the rudder, one on the transom with wires everywhere and an electro eliminator on the prop shaft. I have asked for one to be fitted on the bowthruster ( 25 kgf) but i am at a total loss how that will be fitted because I cannot find any fitting instructions anywhere. So this post is a bit of info for comment and a question about bowthruster anode fitting .Thanks for any responses Mike

Next to a big steel boat could be a problem if you are both connected to shorepower. You dont have to be using the power, just being connected is the problem because the earth connection would be connecting your anodes and other underwater appendages to the big steel hull.
Problems from that should be prevented if you have a galvanic isolator fitted.

A big steel boat with a dodgy electrical system causing "stray" currents thorough the water might be a problem if a path through your boats systems provided a lower resistance path for them than through the water.

"wires every where" might be your problem. There is a tendency to create problems by over enthusiastic bonding. I hope you do not have any non ferrous though hulls bonded to your anodes.

cannot help with your bow-thruster. If the manual does not show how/ where an anode can be fitted a nearby hull anode might be the only solution but I guess undesirable. Why do you want to fit one. What is the problem with the bow-thruster that you are hoping to cure.

 

[Firefly625]

AFAIK most bowthrusters are fitted with anodes.. what's the make & model?

 

[rbcoomer]

If you are really not 'permanently' connected (as opposed to 'not using') then I'd look very carefully at construction of everything metal in contact with (or very close to) the water.

The current must be flowing somewhere and either there's a very significant current when you are connected in order to erode the anodes, or it's leaking somewhere else. As VicS says, what about thru hull? Also consider any plastic fittings if they connect/allow contact of saltwater to copper/bronze pipes etc within the boat...

 

[VicS]

AFAIK most bowthrusters are fitted with anodes.. what's the make & model?

The 25kgf Vetus one does. I just read the instructions! It's a collar on the tail piece behind the propeller.

 

[whisper]

Just come out of the water for annual antifoul and new anodes. In the boat yard I
I was aked if I am permanently connected to electricity on the pontoon because my anodes( 12 months old are pretty corroded).

Blimey, you've done well for them to last 12 months. We have to change zinc ones twice a year, aluminium ones about every 9 months. No shore power and no other boat nearby.

 

[Firefly625]

The 25kgf Vetus one does. I just read the instructions! It's a collar on the tail piece behind the propeller.

Oh yes, so obviously that's long gone