On Thu, 05 Feb 2004 15:18:07 GMT, "RichG"
wrote:

Hmmmmm. your query brings up a question that I need answered too.

If I remember correctly, the anode ( rust-preventive sacrificial anode) that
is on every engine MAY be a different alloy for Sal****er versus Freshwater.
I'm doing the opposite of you. I am moving a 16 ft. Carolina Skiff from the
Texas bay system to my place in Lake Geneva, Wisconsin. Perhaps I should be
changing the anode coincident with that move???

Anyone know the answer????

I'll give you the basic course in chemistry. The following is a pet
peeve of mine.

Electrolysis is the result of stray current. The corrosive effects
can be the same as:

Galvanism - which is the correct term for the corrosion caused by
contact between two dissimilar metals.

A sacrificial anode basically reverses the flow of electrons and
neutralizes the current flow between dissimilar metals. The anodes
are made of zinc and in the process of neutralizing the current flow,
self destruct (technically, that's not what happens, but for all
practical purposes, that's the answer).

To answer your question, yes - different zinc alloys for different
situations, however I assume your boat is trailored so I wouldn't
worry about it all that much other than to just watch the ones that
are there and replace them once in a while.

Good luck.

Later,

Tom
S. Woodstock, CT
----------

"To the fisherman born there is nothing
so provoking of curiosity as a fishing rod
in a case."

Roland Pertwee, "The River God" (1928)