Sounds like a care and storage problem daniel. I live in houston with VERY high humidity. I have zero problem with rust/tarnish. after each shave I fold over a piece of TP and wipe from the spine end, let dry open in a stand. After that I give it a wipe with TP that has camellia oil on it. Store in a case in the bedroom after. I hardly ever get the scales wet or the pivot area. The key here is care of the razor. I rinse it off with HOT tap water after the shave on just the blade part.
Hope that helps.

Paul