How Does CLR Remove Rust?

Updated February 21, 2017

CLR, or Calcium Lime Rust Remover, is a popular cleaning solvent. Not only does CLR remove the calcium and lime deposits caused by hard water, but it also removes the rust caused by the corrosion of metal. Rust is a common problem on many surfaces and is a cleaning issue in many households. There are many ways to clean rust stains, from homemade remedies to commercially prepared cleaners. Calcium Lime Rust Remover is a quick and easy way to remove rust stains throughout the home.

What Is Rust?

Rust is created when metal and water come into contact. Iron, aluminium and copper are three metals that rust, but iron is the one most people are familiar with. Metal, water or moisture, and oxygen are the three components necessary to create rust. When the metal gets wet or moist, the water molecules react with carbon dioxide molecules that are present in the atmosphere. This reaction creates carbonic acid, which then weakens the chemical bonds of the metal. The metal starts to break down, or corrode. Corrosion is an electrochemical process and is also known as rust. As the metal corrodes, the water molecules--2 parts hydrogen and 1 part oxygen--break down, which results in a free oxygen molecule. This oxygen molecule combines with the corroding metal to create a new compound. The new compound is an oxide. Iron becomes iron oxide and aluminium becomes aluminum oxide. These are the scientific names for rust, depending on the metal involved.

How CLR Removes Rust

An acid is usually used to remove rust stains. Citric acid (found in some fruits) and acetic acid (found in vinegars) are two of the acids used in homemade rust removers. Commercial rust removers offer perhaps the best solution for really stubborn rust stains. CLR is a very strong stain remover and is made of chemicals that could be harmful to some individuals. As a commercially made cleaner, CLR has a proprietary formula, so its ingredients are not available to the public. According to the CLR website, the product is an “Aqueous Acidic Cleaner.” The site also states that this stain remover is “the only patented lime and rust remover on the market today.”

The most important thing to remember in using CLR is to read the instructions on the container carefully and follow all directions. It is best to use CLR in a well-ventilated area. Rubber gloves are also necessary. To clean rust stains, spray or pour a small amount of the CLR cleanser onto a rag, cleaning cloth or sponge and then saturate the rust stain. No scrubbing is needed. CLR quickly dissolves the stain. After 2 minutes, completely rinse the treated area with cold water. CLR is best used on hard surfaces such as porcelain, metal, brick and chrome. With CLR you can remove stains from toilet bowls, bathtubs, sinks, fibreglass and stainless steel. But CLR is not suitable for all surfaces. CLR should not be used on fabrics or woods. CLR is also safe for septic tanks.

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