Brake Drum Rust Protection?

[Fred A]

Just bought some new iron drums. Still in the back of my car, they are starting to flash some rust. Not to the question, why are the Drum/hub so damn heavy? Back to the rusting, what can I do to slow the rust until I can paint or should they be painted immediately. Original drums are noticeably lighter. Never heard of unsprung weight in China? Even worse, they say USA. Thanks: Fred A