How Does Chrome Rust?

All metals rust when exposed to water and air. While iron is the metal usually associated with rust, chrome, aluminum, copper and other metals rust as well. Chrome is the more common term for a process called chrome plating. In this technique, a thin layer of chrome is placed over another metal. Chrome is a metallic material made from chromium and it has a silver color. Chrome has many uses including the manufacturing of furniture and other decorative objects. When chrome objects are used outdoors they stand an increased chance of developing rust due to the weather. Rust is an electrochemical process that is very common in the home. There are many commercial rust cleaners on the market. Homemade remedies are also effective as rust removers.

Rust is the corrosion of a metal. It is an electrochemical process in which the constituent parts of an element break down and combine with other elements to form a new compound. There are various types of rust because elements such as iron and copper are chemically different. This also leads to rust having a different visual appearance depending on the metal involved.

There are three components to chrome developing rust: the metal itself, water or moisture and air. All of these components must come into contact with each other for rust to form. When chrome gets wet and the water is not immediately wiped away, the water molecules start to react with the carbon dioxide that is in the air. (People breathe in oxygen from the atmosphere and exhale carbon dioxide.) The water and the carbon dioxide react to each other and form carbonic acid and this acid weakens the chemical bonds of the chrome. Because of this weakening the chrome starts to dissolve and wear away. During this same time the water molecules also break down into hydrogen and oxygen. The two hydrogen molecules are released into the air, but the oxygen molecule combines with the dissolving chrome to form a new compound, which is rust. This new compound is a chromium oxide, the scientific name for rust.

Most chrome rust stains are removed with mild forms of acid. When the rust remover is applied to the rust, the stains become water soluble and are now easier to clean. One good homemade remedy is lemon juice, made of citric acid. Apple cider vinegar, made of ascetic acid, is also a good rust remover. With the citric or ascetic acid you saturate the chrome rust stains and let the acid set in. For tough stains add a little bit of salt to the stains. Rub gently with a damp cloth. Repeat this process if needed. There are also commercial rust removers like CLR (Calcium Lime Rust) Remover, which is very effective. With these commercial products, carefully read and follow the directions. After removing the rust, the chrome will look like new again with a high-polished sheen.