Electrolysis eating fuel coolers

[Europeanautoctr]

I own a 2005 Searay 39 Dancer with cummins 5.9 qsb’s. The starboard fuel cooler let go & racor water alarm goes off. I have owned the boat since new. 1st cooler let go in 2011 at 600 hours. Replaced cooler ran ok for 2 years (200 hrs) then let go again. I have replaced every 2 years since. All my zincs on starboard side( lower after cooler, trim tabs, water strainer pick ups for starboard engine, a/c all only last 3 months. The starboard after cooler lower part of hounsing cracked for electrolysis & distroyed cooler. Any Suggestions???
Thanks.

Topic

[james]

Shore power

I was having trouble with exessive zinc consumption and had a galvanic survey performed. The system was entirely intact and we were puzzled. We then did a check of the power post on the dock. What we found is the power post was sending .005 volts back to the boat, causing all my issues. We installed a galvanic isolator and zinc consumption became consistent with my neighbors.

[Rob Schepis]

I’ve done a few boats with the reference electrode Phil is recommending. It is a nifty tool. Here’s a scan of the booklet that is provided with it. (scanned document removed due to copyright)

[Philip]

Might be time to play with something like this:

http://www.boatzincs.com/corrosion-reference-electrode-specs.html

[Europeanautoctr]

I have thrown everything away. (so wife does not see $$$$$$$) I boat in Long Island Sound/block Island sound, Salt water. It has been mentioned to me since my starboard side is my home dock side, that may be stray electricity in the water. I only use factory cummins parts, I keep extra cooler on board, have changed while on vacation. Lucky I own auto repair shop so I am doing all work myself.
My port side(non dock side) still has original cooler (1,100 hrs). It seems like the starboard side of the boat is hot with electricity???? I have tried to find a good electrolysis guy here, none to be found that are good.

[Philip]

First off how about some pictures?.

Second, where do you operate? Might be worth just removing the fuel cooler.

Phil

[Author]

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