Corrosion is when the surface of a material wears away, usually due to exposure to the elements or frequent handling. Water and oxygen can also cause metals to corrode. Corrosion is more commonly referred to as rust, patina or tarnish. Copper, when corroded, turns from orange to brown. Nickel changes from a dull silver to a grey colour when corroded. You can easily remove corrosion with the proper solution, which depends on the material.
Mix a solution of warm, soapy water. Be sure to use a mild soap so as not to damage the copper or nickel items.
Soak the items in the warm water for 10 to 15 minutes to allow the dirt and debris to loosen.
Use a soft cloth or toothbrush to gently remove any corrosion from the nickel or copper items.
Let the items soak in the soapy solution for another 10 to 15 minutes.
Rinse the items and allow to dry. Repeat the process if necessary.
Copper can be soaked in grape seed or olive oil for one to three days to remove corrosion. Nickel can be cleaned with an ammonia solution (one part ammonia, two parts water) if the above instructions do not give the desired results.
Do not use harsh chemical cleaners to clean your copper or nickel. This can cause the items to become damaged and worthless.