Rust Removal Basics

What is rust?

Rust occurs when oxygen and water come in contact with iron or steel (iron with carbon in it). The water can be in liquid form or in the form of moisture in the air. This is why iron or steel can rust either when it is exposed to air or under water. Rust is actually oxidation that occurs when the iron molecule takes on an oxygen and a water molecule.

What is corrosion?

Corrosion occurs when the iron or steel starts to break down due to oxidation (also known as rust)

Does oxidation occur on other metals?

Yes-oxidation occurs on any metal that when exposed to air and moisture begins to form an oxide layer on the surface (ie aluminum oxide, copper or cupric oxide or zinc oxide etc).

Is oxidation on other metals usually as destructive as it is on iron and steel?

Oxidation or rust on iron or steel will continue as long as it is exposed to moisture and oxygen. If left long enough, the rusted part will corrode completely and disappear. Other metals such as aluminum oxide will generally just form an oxide layer on the surface and stop. This is because on non-ferrous metals (those metals not made up of iron and steel) the corrosion actually forms a barrier layer on the metal stopping the corrosion. This is referred to as passivation.

Why does it continue with iron and steel?

Because as iron and steel rust they form iron oxides that flake and fall off exposing more underlying fresh iron.

Will anything accelerate rust?

Yes, salt, certain sulfer and carbon materials and heat.

How do you remove rust?

Rust is typically removed in three ways:

• Acids
• Alkaline
• Chelating (generally neutral)

Acid Removal

As rust is an oxide, the use of certain acids that are deoxidizers (ie sulfuric acid) will remove rust.

Alkaline Removal

Alkaline materials (ie sodium hydroxide) have very high pH (very basic) and remove rust by dissolving it.

Chelating

Chelating is a process where a rusty part is exposed to a chemical that bonds with the rust and then pulls it away from the surface of the metal. The rust molecule has a greater attraction to the chelating chemical than it is to the steel or iron.

Why RR100L

RR100L

• Is a chelating rust remover
• Is neutral (pH 6-7)
• Is non hazardous
• Is non-fuming
• Is non-toxic
• Is biodegradable
• Fully water soluble
• Works at room temperature
• Works at concentrations from 10%-100% (the higher the concentration, the quicker it works)
• Can be heated to speed rust removal (up to 120° is optimum)
• Removes rust to the base metal
• Safe on all metals, plastic, paint etc
• Helps prevent further rusting after removing rust

For more information, or to order Stone Chemical products, please call 630.305.0538 or fill out the form on our Contact Page.