There are a few things you can do to clean green corrosion off metal. The first is to use a mild soap solution to clean the area. This will remove any built-up oils and grease that may have been on the metal. Next, use a wire brush to scrub the area with gentle circular motions. Be sure not to overdo it, as this will cause further damage to the metal. Finally, use a heat gun or an oven to heat up the metal and then apply pressure with a cloth or paper towel until the corrosion has melted away.
