JAXAshby wrote:

zincs will help protect submerged wood on a boat. It is
subject to some galvanic corrosion also.


really? wood becomes the anode or the cathode? I guess I have never seen a
battery with wooden plates before.

My understanding is this: Wood is neither the anoode or cathode -- or
rather it is both.

To diverge, brass is a combination of two metals (copper and zinc,
perhaps.) The two metals will corrode each other in salt water. Little
pockets of zinc corrode with little pockets of copper. It
self-destructs. It is not just cannabalistic, but self-dissolving.

Wood has various components as well. It is possible that these
components will self-destruct. The amount would vary with the type of
wood, age, finish, and many other things that I don't understand. If
this explanation is not correct, then the suggestion that wood undergoes
electro-chemical degredation with near-by fittings, fasteners, and
such-like is certainly a possibility. If this were true, it would
certainly

I seem to recall reading this in a sailing magazine in an article about
galvanic corrosion. I may be in error. This discussion is not one that
is important enough to me to research. Do you know of any authoritative
sources that you can reference? I have about 3 feet of old Wooden Boat
magazines that you can have for free (you pay shipping) if you want to
look through them. I am sure that it would be covered there.

Some people seem to consider some of your comments, such as "I have
never seen a battery with wooden plates before." to be unhelpful to the
discussion. It does convey, if nothing else, a certain impatience. For
your own benefit you may choose to change your tone slightly. Even
throwing in a few smilies :-) would change some people's reaction.

Fair winds,

Tom
of the Swee****er Sea