Galvanic corrosion on Brovo 111 outdrive 2004 342

[merwin10]

Hi Raybo

That is not surprising! Most of the marinas around New England are old and basically slapped together before any controls and rules where applied. To really fix a marina electrical system cost hundred of thousand of dollars to bring it to code! There is a simple way to know if a marina is up to code there will be a transformer at the head of the dock to regulate the power for that dock! If you think about it look for the pole transformers for the incoming power to the marina. Very close by will be the meter, distribution box and ground stake it is from this point the power to the dock comes from. There is allot of line lose from there to the dock head. This is where the transformer comes in. The transformer is special it boosts the dock power to the correct level provides a local ground and provides isolation. It also prevents any induced stray voltage or noise from the dock! The clean power is then distributed to the dock!

Of course this does not prevent other local problems (non-Marina related) from effecting galvanic corrsions. The ony way to prevent that is with an on-board system!

Mike - 

[ebuddha5]

I am thinking about getting a GI unit for my 2004 Fiesta Vee 270.  They are around $300 though and that kind of sucks.  I replaced the anodes (all except one that had a sheared bolt) and hung a second anode off my dock right next to my propeller grounded to the aluminum on my dock which runs to the seawall.

I have light corrosion on my out drives, so I am not terribly worried, but I do have some oxidation on my prop.  I am hoping the new anodes keep it all clean going forward, I am still on the fence about the GI unit, my boat has all kinds of after market stuff on it, new stereo, flat panel screens etc...

[fmrosell]

This is a great story....opens up a whole host of possibilities to check, if you are having electrolysis problems....

[mightys4]

This is an excellent discussion, as my BIII is extremely beat up from GC!

Thanks to all those with the great input!

[raybo3]

Hi Mike Last year I checked the electric service feeding the docks. In very good shape. All grounds isolated from the neutrals and no corrosions at all. The load is unbalanced but I will take care of the this summer. However we do not have an electro-static isolating transformer. We do have a GC problem that I think might have something to do with a 4 lane draw bridge about a 100 yards away. This bridge hardly ever gets opened. We also have a very strong current some times up to 5-6 knots. The first year I had my 342 my wife got sick and did not use the boat. When I took it out of the water I wanted to cry....LOL my B3's were a mess. I have babied them ever since. Now I have the boat hauled and rezinced in Aug. I plan on checking the boat with a probe and meter to see if my boat is a problem or if it is comming from someone else. I will keep you posted...

[merwin10]

Hi

Shore power at marina's are notorious for power problems! Some of the equipment on a boat is not very tolerant of low power! Many thing that if they are plugged into a 30Amp 110volt service that is what they expect to see on the boat! Take a look around your marina! Check out the yellow power cords! Pay close attention to the plug end! If you see brown or black around the prongs you can bet you have a low voltage situation! All you need to do is go to a receptacle on your boat, stick a multimeter set to above 120 and measure your incoming voltage! This is particularly true when all the boats are in port around dinner time on a hot day! All the boats have their Air Conditioners running and stove tops etc. cooking dinner! Just remember the watts equation Voltage X Current equals Watts. So if a boat is calling for so many watts of power and the voltage drops to 90 volts guess what the amperage does, right it has to go up to maintain the wattage!

How if you happen to have one of those yellow power cords with brown around the prongs I suggest you replace it ASAP! As when the brown finally turns black that is carbon build up of the plastic plug deteriorating due to heat! Carbon conducts electricity and acts like a resistor causing the plug to over heat and then catch on fire! I have seen plenty of them catch fire!

As I said there are a few pieces of equipment that are not tolerant of low voltage and they usually have a compressor on them I.E. Freezers, Refrigerators and Air conditioners!

Good luck on your search!

Mike -