Wondering if being plugged into shore power increases zinc c

[zinbaad]

Since keeping Mahalo in the water over the winter and seeing most of the zincs disapear I was wondering if the electric shore power, while hooked up has any direct relationship to the extent of zinc corrosion as opposed to not hooking up shore power on a daily basis.. Any input oput there?

[jleonard]

I have always been told that it does, however I plug in 24/7 and normally all my zincs are done after a summer season anyway.
You could do some electrical checks and probably understand your situation better.
For a few seasons I had a boat with twin I/Os in the slip next door...my zincs lasted better those years. LOL In this case my neighbor was helping me but I was probably hurtuing him. Point being it ain't just you.
The best thing you can do is make sure all three legs on your power cord and the mates are corrosion free. I keep mine clean with Scotchbrite and spray corrosion block on them. That helps reduce stray voltage.
I was also always told that if the zincs are NOT wearing out then they are not doing their job.

[zinbaad]

Anyone else have an idea?

[Carl]

There is lots of info on this subject all over the net......just google it and start reading. The link below is a short and sweet version. All marinas are different and one slip varies from the next based on what condition the electrical systems on the surounding boats are in. My zincs would be about gone by July until I installed a galvonic isolator. Last year they lasted all season with some to spare. To answer your question, yes it does increase zinc corrosion. Once you plug in you are connected to every other boat through the ground wire.



http://www.pkys.com/FAQ/galvanic.htm

[RicM]

Yes it does. The same boat on a mooring (away from stray voltage and not plugged into shore power) will have MUCH longer zinc life. The ground wire (always connected whether your AC is on or not) is connected to every other boat in the marina that has a shore power cable connected to it. All the metal parts below the water line on all those boats are connected and submerged in salt water, an electrolyte. This makes the whole marina into a giant battery, generating mini volts at the expense of your zincs. That, however, is better than it being at the expense of your props. Zincs are more accurately referred to as "sacrificial anodes". If you you don't have a galvanic isolator installed it's worth it just for peace of mind if you leave the boat in year round.