Steve wrote:
I have noticed that the continued wire seems to have survived well.
i.e. the boat is 20 years old and the original stuff is which was
mainly
continued is fine. I can see no signs of corrosion even after
stripping
large lengths.

Had the 30 year old windspeed meter on my sailboat cease working
recently. Investigation revealed the 60 foot sensor wire had a break
in it somewhere. Connections looked OK. No visual sign of damage, but
cutting it in about the middle revealed black crumbs instead of copper
wire. Turns out entire lengths of the wire had corroded to dust.
Probably had worked so long because it was only handling a half volt or
so AC signal. It was non-tinned and had lousy insulation, sort of like
extension cord wire.

So it can happen, at least in small gage wire.