Opinions on galvanized wire w/o Serving

[Jak Mang]

I recently saw a 1930s era schooner with galvanized standing rigging. The owner claimed the wire was under a year old, but it was not served and showed a lot of rust. How long can this wire be left unprotected before there is permanent damage? Can the wire be cleaned and then served to protect it or will the rust continue?

Thanks,
-jak