Bottom paint and zinc anodes

[Brickbat]

I used VC17 over primer on a new hull for sailing in in the great lakes.It wore very well for the first year of sailing except around several zinc anodes where the finish self destructed.(Photo attached). I am trying to find magnesium anodes for replacements, but in the meantime I need to find a finish to use in these areas that won't react with the zinc and is not incompatable with the VC17. Any thoughts would be appreciated.

[foggysail]

Does your boat have a metal hull? I don’t understand why an anode would be located on the hull so far away from metals..... assuming the hull is fiberglass.

IF FIBERGLASS, my guess is that there should NOT be an anode there but instead a sintered copper ground plate to protect the boat from lightening.

[boatpoker]

Originally Posted by foggysail

Does your boat have a metal hull? I don’t understand why an anode would be located on the hull so far away from metals..... assuming the hull is fiberglass.

IF FIBERGLASS, my guess is that there should NOT be an anode there but instead a sintered copper ground plate to protect the boat from lightening.

Completely agree, ... You have "several zinc anodes" why ? .... and what on earth is that anode in the photo bonded to ?

Hanse did not build it that way.

[Brickbat]

Thw hull is fiberglass. Why the anodes are there is a question I can't answer. I presumed they were part of a grounding system. I have to find what the connections are inside the boat the next tie I get to the boat.
Hanse did build it that way and recommended the anodes be replaced with aluminum or magnesium for fresh water.
Thaanks for your responses.

[boatpoker]

Originally Posted by Brickbat

Thw hull is fiberglass. Why the anodes are there is a question I can't answer. I presumed they were part of a grounding system. I have to find what the connections are inside the boat the next tie I get to the boat.
Hanse did build it that way and recommended the anodes be replaced with aluminum or magnesium for fresh water.
Thaanks for your responses.

I live about 2 miles from the local Hanse dealer and work around those boats about 3 days per week. I've surveyed quite a few and never seen an anode like that or in that position on a Hanse. You say "several" anodes. How many and where are they ?

PS. Yes, magnesium or aluminum for fresh water.

[foggysail]

Originally Posted by boatpoker

I live about 2 miles from the local Hanse dealer and work around those boats about 3 days per week. I've surveyed quite a few and never seen an anode like that or in that position on a Hanse. You say "several" anodes. How many and where are they ?

PS. Yes, magnesium or aluminum for fresh water.

The location shown for his attached anode is where I could expect to see a dynaplate which would be electrically connected inside to the boat's bonding system. Could be that someone who didn't understand the function of a bonding plate, thought it was an anode replaced it with an anode.

[boatpoker]

Originally Posted by foggysail

The location shown for his attached anode is where I could expect to see a dynaplate which would be electrically connected inside to the boat's bonding system. Could be that someone who didn't understand the function of a bonding plate, thought it was an anode replaced it with an anode.

I wouldn't be surprised. but as a Certified Marine Corrosion Analyst I am really curious about the other "several" anodes.

[macman4190]

Reminds me of a Frigoboat keel cooler with zinc anodes - except the zinc anodes have been depleted. They should be filling those two mostly empty circles. But the keel cooler plate in this picture seems deeper than that. Could it be something along those lines?

[Brickbat]

Your dealer sent someone down to look at this boat a few months ago as it is an updated model of the 345 and there aren't others around. Guess I should have waited for them to perfect it.
There are two of these anodes (as defined in the manual) and the boat was delivered that way. I have yet to open up the interior and find what they are connected to.

[boatpoker]

Originally Posted by Brickbat

Your dealer sent someone down to look at this boat a few months ago as it is an updated model of the 345 and there aren't others around. Guess I should have waited for them to perfect it.
There are two of these anodes (as defined in the manual) and the boat was delivered that way. I have yet to open up the interior and find what they are connected to.

Why on earth would any dealer deliver a new boat with "zinc" anodes to the Great Lakes ?

[Brickbat]

"Why on earth would any dealer deliver a new boat with "zinc" anodes to the Great Lakes ?"

That question is one that really is bugging me lately along with several others of the same ilk.