When metal comes into contact with air and moisture, the metal begins to form a layer of rust on the metal’s surface, this is called oxidization. After thorough cleaning, rusting can be stopped by a certain process called galvanizing. Although it may seem that the metal is unrecoverable, sometimes metal can be restored to what it was originally. By following these steps, metal can be restored.
Use a bronze or copper wool
Use a bronze or copper wool sold at supermarkets (usually advertised as pot cleaners) to scrape rust off. This will ensure the original finish will not be as damaged as it would be if you used a steel wool or brush.
Use a steel wool or wire brush
If you need to use a steel wool or brush, make sure not to use any oils when scraping with the steel wool or wire brush. The reason for this is because the scrapped of rust is an abrasive material and when made into a sort of oil/rust paste, it can damage the finish. Instead, scrape the metal only when dry and occasionally wipe off the free rust on the metal object to avoid further abrasion. Heavily rusted items will have to be worked on with more drastic tools or chemicals.
Use Abrasive Shotblasting
Use abrasive media blasting with a variable air pressure to mechanically remove the surface rust back to the base clean material (media of sand, steel shot, glass bead etc.
Use Water Jetting
Use high pressure washing with abrasive media added to the flow stream depending on the severity of the rusting and the robustness of the base metal (media can be sand, steel shot, glass bead or soda crystals)
Use chemical removers
Chemical rust removers can be effective, yet dangerous. Phosphoric acid or Oxalic acid are what makes it so effective, but it is dangerous for these chemicals to come into contact with your skin, therefore wearing heavy duty rubber gloves and a mask are advisable. Also, please read the instructions VERY carefully.
Use white vinegar
Instead of harsh chemicals, use white vinegar to remove rust from the metal objects that you have found. It doesn’t carry any toxins and doesn’t produce any dangerous fumes as well. To remove the rust, rub the object with a cloth soaked in vinegar, then place it in a container filled with vinegar to soak for however long (probably dependent on the degree of rusting). Now all you need to do is wipe any rust off and rinse the object under warm water.
Use baking soda
Baking soda can also be used to effectively remove rust. Take the soda and mix it with a little water until it forms a paste. Spread the paste over the rusted object and wipe it all off when complete. If you are unsure how long to leave the paste on, try leaving it on for an hour and see what the results are. If the rust has only disappeared slightly, then you will know to leave it on for 3-4 hours longer.
Use a power sander
For any minor areas of rust remaining on the metal object, you can use a power sander to remove the excess. Use extreme caution when using any electrical tools that could potentially cause injury.
Use Motorized Tumble Cleaner
Small components can be cleaned of rust in a motorized tumble cleaner which rotates the components in an abrasive media. large quantities can be cleaned by a similar method with a motorized paddle/basket cleaner, throwing media at the components by a rotating paddle.