SS Zinc Eater...still an issue!

[(Nobody You Know)]

Well, after Karl was kind enough to write out an elaborate step by step plan for isolating the cause of (Nobody You Know)'s excessive (IMHO) bi-annual consumption of zincs I, along with the help of a good friend and captain, went to work.

Upon completion of step one in the “Check for DC leakage and bonding system integrity” everything was turned off, “soft button electronics” were removed and put away and batteries disconnected.

The first problem we encountered with the VOM between the leads was continuity that, though I do not remember the exact amount, was considerable. After about an hours search we discovered that the autopilot was on. Switching it off only reduced continuity by say a third, but we still had “considerable”. Soooo, we proceeded with phase two: testing each individual DC circuit breaker. No change in continuity!

This process was repeated on the AC side with the same results. All bonding connections checked out OK and with the shore power disconnected. Once again we spent considerable time trying to run down the cause of the (original) moderate continuity throughout the trials. Even unplugged cell phone DC chargers, switched off the battery main and each engine main, and the battery charger. No change. The only thing I can possibly think of is the way the battery charger is set up, seems I’ve heard that a charger – when not charging – will discharge a battery. But this shouldn’t be to the extent that it would eat zincs at a fast rate?

Don’t know what to do at this point. Think an Isolation Transformer would be smart? (buy zinc ingots and a couple of good hack saws?)

Capt’n Bill

 

[Genesis]

Pull the ANL fuse for the battery charger if you suspect it. That will isolate it; you should be able to find them in the main DC panel(s).

 

[Nonchalant1]

How about your inverter? Sometimes they're hooked up without going through the breaker panel or fuses.

Isolation transformers are excellent (though big, heavy and expensive) but they won't help solve a DC problem. They only help for the AC to shore power issue.

Doug

 

[(Nobody You Know)]

Got it!

Have no inverter. Interestingly, the previous owner installed a (non-marine compliant) cheapie which some months ago gave me a very small zap. Removed it immediately (and subsequently isolated it's power source - disconnect and cap off both at the battery end and supply end - for future inverter application, + & -).

Will however pull the charger ANL fuse. Good suggestion.

Thanks guys,
Capt'n Bill

 

[Genesis]

There IS a DC leak. If its the charger then its of no consequence (its probably normal and just the diodes in it you're reading) BUT you need to know!

 

[luckydave215]

I don't have an opinion re your DC leak. But........in my area, zincs last 3-4 months. This has been standard on my last 4 boats, power and sail, in different marinas about 1 mile apart (but in the same basin).

 

[(Nobody You Know)]

Thanks Dave,

we originally thought the problem to be local to the marina or basin. But when we relocated the boat throughout the spring to two other marinas for a few monthe each the problem persisted - which indicates it is an on board issue.

Refering back to the original thread, which is now part of the FAQ archives, it was pointed out to me that, ultimately, the problem just MAY be the normal nature of my boat. And likewise you may have the same situation.

Capt'n Bill

 

[TedZ]

I may not be following what you are doing well enough, but to do what i think you are trying to do you have to be careful of light bulbs and/or ballast of things that do not turn off when the breaker is off.

I understand you caught lit buttons on electronics but some are wired directly. Lorans and their button lights come to mind, there are other things like bilge pumps that are sometimes wired onto feeds from the batteries prior to the isolation rotary switches and well around 12 VDC breakers.

Just $.02

Ted

 

[(Nobody You Know)]

A good friend in Wilmington, NC has the "sister" to my boat, only 1 year older. Everything is basically identical. He bought most all wiring schematic diagrams from Sam's. I'll be cruising with him next week and will have a chance to review same. My gut feeling however continues to suspect (the) bilge pumps.

Thanks for the input.
Capt'n Bill

 

[fixin-to-cruise]

Just had a diver clean the bottom and props on my 65MY after 18 months in Florida canal water. Had him check the zincs...all the prop shaft collar zincs are fine along with the rudder and trim tab 4" disc zincs - he said they were not worth changing yet. This boat is plugged in 24/7. The bow thruster zincs vanished however...he replaced those and I think I'll check the bonding wires there seeing as how it was (non-Hatteras) installed after the boat was built.

When I first bought the boat I had a new set of zincs installed during the pre-purchase survey and they were almost gone 6 months later.

What I've learned is that the galvanic isolators I installed a few years ago really work! My previous boat, an Albin 43 Trawler used to eat a set of zincs every 6 months. After I installed a galvanic isolator they lasted about 18 months. The zincs on this boat are doing even better.

Install a galvanic isolator!! One of the best things I've done.

 

[(Nobody You Know)]

A galvanic isolator remains an option. However, in light of the possibility of danger to people swiming aroung the boat I'm a little reluctant to go that route at this time. For now I think that I need to make every effort to assure that there are no defects that may be the root cause of this.

Thanks,
Capt'n Bill