Rust is a common affliction among metal objects that spend any amount of time outdoors. Once a metal is exposed to the elements, its iron content reacts with the oxygen in the air to cause the reddish rust that discolours and disfigures its surface. However, even though rust is common, it is also relatively easy to stop. The key to keeping rust from spreading is to detect it as early as possible and treat the affected area thoroughly.
Remove the Rust
Remove all of the rust that has already formed. In cases of extensive rust, begin with a coarse file or coarse sandpaper. Gradually work your way down to finer sandpapers. In cases of light rust, start with fine sandpaper and move to an abrasive cloth. You can use water to reduce friction and a clean rag to wipe away loose rust.
Neutralise Remaining Rust
If the rusted area is difficult to access or rust remains even after thorough sanding, use an oxide conversion fluid to neutralise the remaining rust. These commercially available products transform a thin layer of rust into a matt surface that is fit for painting or refinishing. However, they work best when as much of the rust as possible has already been removed.
Clean the Area
After you apply the conversion fluid and it has dried, clean the entire area. Use a soft, clean cloth and water. Distilled water and vinegar also work well at removing debris or rust that may have discoloured the surface of a nearby area.
Protect the Metal
The area where you have removed existing rust will be especially susceptible to new rust forming, so apply several coats of paint or protectant to the surface. When adding the top few layers, gradually extend the area of your coverage so that you are applying a new protective coat to the areas near where rust formed.
Keep It Clean
If rust formed due to damage or over a long period of time, it may have been impossible to prevent. However, in many cases, rust begins to form where debris collects and erodes the metal's original finish, exposing it to the elements. Consider new ways to keep the area clean, such as wiping it down occasionally with soapy water and a soft cloth or sponge. For outdoor metal objects that rust, consider storing them indoors during the winter. All of these small steps will help prevent or delay the onset of rust in the future.