View Here : How To Stop Rust
3. Use of anti-rust solutions: The alkaline phosphate and alkaline chromate solutions act as anti-rust solutions. When iron articles are dipped into a boiling and strongly alkaline solution of sodium phosphate, a protective insoluble film of iron phosphate is formed on them. This film protects the article from rusting.
Rust is a complicated electrochemical process whereby metal is converted to an oxide whenever it comes in contact with oxygen in the presence of moisture, and that can happen even in the protective custody of your garage.