I have excessive zinc anode replacements

[friscoron]

Hi all,

I bought a 1999 Hunter 376 sailboat in February 2016. I'm a new boater. My Marina is in the Los Angeles Port, CA. Lots of tankers, container ships, Tugs going by marina (I assume a lot of electrical current in the water).

I have a diving service cleaning my Hull every month and replacing zinc anodes. Appears I have 2 zincs on prop shaft, 1 zinc on Flex O Fold prop, 1 zinc on Rudder plate (small).

It appears they replace one of the shaft zincs every month and sometimes both at the same time. They replace the prop Flex O Fold zinc every 2 months. They replace the zinc rudder plate every 2 months. I pay $109-$124 for hull cleaning and zinc replacement. Too much money.

This is my situation:

1) I have an galvanize isolator behind navigational switch board.
2) I have a inverter and no Generator
3) I am always hooked up to shore power.
4) I have a live aboarder birthed next too me.
5) I live aboard boat while I work in Southern, Ca (I am living on boat 80% of time)
6) I have not yet cruised yet, but I plan on it.

Questions:
1) Should I disconnect shore power when I'm not on or using the boat?
2) Hire a ABYC certified boat electrician to troubleshoot issue?
3) Shut on inverter when hooked up to shore power?

FriscoRon
4) Or just move to another marina? LOL

[Adrenaline]

That is way to much and to often to be replacing anode especially as many as you have. I'm thinking you have something electrical hooked up wrong in your boat and that would be my first step in looking for the problem. At least then you will know if it's you or someone or something else in the marina. If the guys next to are not have as much of an issue with their zinc's; then it's pointing to your boat.

[Sailmonkey]

Step 1. Is your galvanic isolator ok, or is it fried? Simple to check with a digital vom set to diode check.

Step 2. Is there stray current present on your shore cord? Easy to check with a clamp on ammeter.


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[sailorchic34]

It could be stray current from a nearby boat or dock which is the fun with stray currents. Oddly not every dock power connection is wired correctly. Seems there is also a boat or two with improper wired 110 panels. It may not be your boat, but a nearby boat. Check with your neighbors and see if one or more has fast zinc loss.

[Tayana42]

Which Marina are you in in Port of LA? Some marinas are "hot". I was in San Pedro CYM for a while and then in Cabrillo Way and went through a lot of zincs fast. Replaced prop zinc every month. Now I'm in Alamitos Bay in Long Beach and zincs last twice to three times longer. Also the cost of your diver seems high for the area. I can recommend Jose Guiterrez (310) 462-0370. He charges me $1.00 per foot (most divers are in the range of $1.50 per foot) and $10.00 to change my MaxProp zinc (that includes the cost of the zinc). I think the 2 large plate zincs on the keel were about $20.00 but they don't need to be changed very often.



S/V B'Shert

[friscoron]

Originally Posted by Tayana42

Which Marina are you in in Port of LA? Some marinas are "hot". I was in San Pedro CYM for a while and then in Cabrillo Way and went through a lot of zincs fast. Replaced prop zinc every month. Now I'm in Alamitos Bay in Long Beach and zincs last twice to three times longer. Also the cost of your diver seems high for the area. I can recommend Jose Guiterrez (310) 462-0370. He charges me $1.00 per foot (most divers are in the range of $1.50 per foot) and $10.00 to change my MaxProp zinc (that includes the cost of the zinc). I think the 2 large plate zincs on the keel were about $20.00 but they don't need to be changed very often.



S/V B'Shert

My boat is located at Island Yachts Marina Berth 205D, Wilmington next to the train draw bridge. I tried to get Jose but he was too busy. I got D-IVES, Keith Ives cleaning hull and replacing zincs. I realize he is high, but I got to take care of my shaft, prop and boat.
Ron

[Tayana42]

Best of luck Ron. I have friends in Island Yacht Anchorage, I think, and they are hot too.


S/V B'Shert

[grantmc]

Why not ask the Dive Service what they think the problem is and whether it is localised to just a few boats where yours is moored. Anodes should should last 12-24 months as the Dive Service staff will well know.

Probably a steel boat very close by incorrectly wired.

[michaelratinter]

The PO of my boat had her in San Pedro Marina, near yours. He used the boat every weekend but disconnected shore power between time. He said leaving shore connected ate up the zincs.

[Bleemus]

Take an ammeter and check yours and nearby power cords for signs of leakage. A quick, non-invasive and easy way to finding a source for the stray current.

This guy has a good explanation of the process but the first easy test is to put an ammeter on the shore power cord and if you are lucky the appliance causing the leak to ground will be running . . .

https://gilwellbear.wordpress.com/20...sts-for-boats/

[SJFK]

We had the same sort of issue in the marina we use during the winter in the UK. Funny thing though is when we move onto a mid stream pontoon in summer, with no shore power and far fewer boats around, our anodes last so much longer.
So, based on my experience, you will either have stray current from the marina electrical connections, or your neighbours are not as diligent as you are in replacing their anodes, and rely on yours instead. You could try hanging an anode over the back of your boat, to provide additional anodic protection. I see that more frequently being done now, especially in marinas. If that does not work then go through the checks as others have suggested to determine the source of your problems before you do anything else.
Good luck

[jamhass]

Try just moving slips (if you can.) Same thing happened to us some years ago. Just moving completely solved the problem for us.

As already noted disconnecting from shore power can indeed make a big difference.

[fstbttms]

I have been told by boat owners in virtually every one of the dozens of marinas I have worked in over the last 22 years that their marina is "hot." Usually this is not the case and is the result of the boat owner simply being in denial about the state of his own electrical system. Rapid anode depletion is almost always the result of an electrical issue aboard the boat in question. Cudos to you for acknowledging that possibility.

The anode loss you appear to be experiencing is extreme. I would recommend you do two things:

1.- Have a marine electrician go through your electrical system to suss out the problem. If he can't find one aboard, have him check the shorepower system and for any stray current in the water. If there is an issue with either of these last two items, request that the marina alleviate the issue.

2.- Require the dive service to leave all anode remnants on the dock each and every time they replace one. It is a little suspicious that they have "forgotten" to leave the majority of the anodes they are replacing, especially since they are replacing them so frequently. They should be concerned with providing you with evidence of the problem. If they seem to be unable to do this, find another dive service.

BTW- the rudderplate anode is mounted on your strut, not on your rudder.

[fstbttms]

Originally Posted by grantmc

Anodes should should last 12-24 months as the Dive Service staff will well know.

While the OP's anodes are being replaced very frequently (whether because of rapid depletion or rampant greed), in this dive service owner's experience, shaft anodes should last 6-9 months. Excessively more or less than that is indicative of a problem. A shaft anode that lasts for two years is likely not doing its job, IMHO.

[fallingeggs]

The way to figure out the problem is to test your boat using your multimeter and a pencil zinc. This is the tool a professional electrician will use.

I believe making your own is easy enough, but you'll need certain known values to test against and the testing procedures. This info can be found on this forum and others if you search long and hard.

Or you can buy the rather pricey package from BoatZincs.com that comes with the pencil zinc (actually, some silver thing) and a manual. Follow their manual and you can pin point what the problem is and how it can be fixed.

I did the second option myself. I have some grounding problems, but also a hot marina. I upped my zinc count to get within the protective range (determined by taking measurements with the pencil zinc). Working on wiring this winter. A hot marina is harder to solve, but I'm moving to warmer waters within the year.


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