Rather than grinding, sanding or using harsh, toxic chemicals to remove rust from old tools, vintage decor, family heirlooms, hardware and other objects, opt for a gentler option. The acid in everyday distilled white vinegar, with the aid of salt, will eat through the rust and corrosion afflicting the metal, making it possible for you to scrub it off later with an abrasive pad.
Make the Vinegar Solution
Fill a large container made of a non-reactive material, such as plastic or glass, with 1 gallon of distilled white vinegar. Add 1 cup of table salt and stir the mixture to combine. The salt will increase the potency of the acid in the vinegar, making it even more effective. Use 1/2 gallon of vinegar with 1/2 cup of salt for smaller objects.
Soak the Object
Place the rusty object into the vinegar and salt solution, making sure it is completely submerged. Allow the item to sit in the liquid for anywhere from 12 hours to a few days, depending on how rusty it is. Check the object periodically after 12 hours to see how loose the rust is becoming.
Note: Vinegar reacts differently to different metals. For example, it removes the protective oxide coating from aluminum before it begins to corrode the metal itself. Therefore, you can damage aluminum if you leave it in vinegar for long periods. Check any metal in a vinegar solution regularly to assess its condition. Do not use this rust-removal method on valuable or delicate metal objects.
Scrub the Loose Rust Off
Put on a pair of rubber or latex gloves to protect your hands from the rust. Scrub the loosened rust off of the object using an abrasive item, such as steel wool, a brass-bristled brush or even crumpled aluminum foil, depending on what you have on hand.
Neutralize the Acid and Remove Moisture
Fill another container with 1 gallon of water and 1 cup of baking soda, stirring to combine. Soak the rust-free object in the solution for approximately 10 minutes to neutralize the acid in the vinegar. Next, scrub the object with the abrasive item once more if needed to remove any remaining rust, and then rub it down with a pad soaked with denatured alcohol to remove any excess moisture. Rub the metal with light machine oil or gun oil to prevent it from rusting again.