As antique metal ages, it is exposed to environmental elements like humidity that affect the chemical composition of the metal, leading to oxidation and eventually rust. Cleaning the oxidation off antique metal is a delicate process that requires multiple cleaning passes to prevent damage to the antique. If you do not remove oxidation and rust from antique metal carefully, you risk making the antique less valuable than it was with the oxidation.
Visit a hardware store or a home improvement center to buy rust remover. The rust remover should be reasonably mild because you are dealing with antique metal. Choose a rust remover with phosphoric acid or a mixture of different chelation agents.
Remove any non-metal materials from your antique, if possible. The rust remover could damage or dry out materials like wood or plastic.
Clear away any big chunks of oxidized metal and rust that have collected on your antique metal. Use the emery cloth to lightly remove the larger pieces of oxidized metal. Smaller strokes with the emery cloth will prevent scratches to the surface metal of the antique.
Test the rust remover on a small part of the antique's surface metal. Look for a place on the underside of the antique, if possible. The reaction of the rust remover on your antique depends on the condition and composition of the oxidized metal. Successfully testing the rust remover on the antique's surface ensures that you won't damage the metal.
Fill your plastic bucket with rust remover once you have tested the substance on the antique's surface. Submerge the metal of the antique into the liquid for a few minutes. If your antique is too large to fit inside your bucket, clean the oxidation off the antique by pouring small amounts of the rust remover onto a towel and gently rubbing the solution on the metal.
Dry the antique with an unused section of your towel. If the oxidation is not completely removed, try cleaning the antique with the rust remover again.