On Thu, 09 Sep 2004 08:06:35 +0200, Meindert Sprang wrote:

"Mac" wrote in message
news

I believe that the effectiveness of a zinc diminishes somewhat as distance
from the protected metal increases. So you probably want to hang the zinc
pretty close to the prop. I'd use galvanized steel wire to suspend the
zinc.

Uhm, what do you think would happen to the zinc coating on the gavanized
wire?

Meindert

Well, as far as the water is concerned, everything in this system looks
like zinc. So in the absence of stray electric fields, there isn't any
strong reason for the galvanization (or anodes) to wear away too fast.

If the electric fields in the water (or time) cause the galvanization
to wear away, then the anode will protect the steel until the anode is
gone. Then the steel will rust. This will be obvious upon inspection, and
can be dealt with by replacing the cheap galvanized wire and adding
another anode.

I specified galvanized wire, as opposed to copper or stainless wire,
because the galvanized wire won't cause the anode to disappear as quickly
as those other metals will. Aluminum wire might work OK, too. But once the
anode is gone, the aluminum might disappear rapidly, and the oxidation
might not be as obvious as rust on steel. I've never used aluminum wire
for anything, so I don't really know what would happen.

Anyway, for similar reasons, never use stainless seizing wire on your
galvanized anchor shackle. Use cheap galvanized wire. The stainless (or
monel) wire some people use actually causes the rode to function as an
anode. Eventually the links near the shackle will rust, long before the
rode as a whole needs regalvanization.

--Mac