Remove paint, grease, and dirt from the metal
Sand or wire-brush the surface to expose bare metal
Spray or wipe with saltwater
Spray or wipe with white vinegar
Apply hydrogen peroxide
Add table salt to speed oxidation
Keep the metal warm and damp
Place it in a humid environment
Reapply saltwater and peroxide every few hours
Lightly mist with bleach for faster rusting
Scratch the surface periodically to expose fresh metal
Use steel wool or iron powder to seed rust
Avoid sealing or drying the surface between applications