"chuck" wrote in message
nk.net...
Hello Steve,

But the suggestion that unbonded bronze thru-hulls caused accelerated zinc
loss in the presence of stray currents in the 120 vac marina ground wire
is outside my understanding of electrochemistry. A much more likely
culprit is a nearby, unprotected or underprotected boat that is using the
green wire to complete a galvanic cell.


Chuck, just to add further information to the discussion, I had the marina's
electrician measure the stray currents after the Galvanic Isolator was
installed. He stated that the boat now was protected from the stray currents
in the slip. However, he measured the boat in the next slip, which is
basically in totally run-down condition...boat is never used and not
maintained...and it appeared that this boat was the culprit (confirming your
statement above).

So, based on all the valuable information in this thread, I am going to have
a diver inspect the zincs and the seacocks within the next month...and in
addition, I plan to have the seacocks inspected and serviced on the next
scheduled haul-out in the Spring.

In the meantime, I will try to control my paranoia and or guilt or
whatever... :-)

Claus