Rusting is a chemical process, thus it is not reversible. Rust makes the main metal object weaker; the main structure degrades and deteriorates completely with time. Molecules of iron oxides or rust are larger than iron molecules. Hence, when a specific mass of iron gets converted into rust, it dilutes and expands.

That is why rusting iron structure fails to withstand load and breaks down. Surfaces of rusting objects swell, puff up and flake when rust formation begins. Rusting begins on the surface and then it penetrates deep making the whole piece fragile.

Presence of water is essential for rusting. Iron and steel cannot rust when they are dry. Being an alloy, steel rusts faster than iron as it is more likely to undergo electrochemical reaction. Steel rusting is often discussed as galvanic corrosion.

It is worth mentioning that impure water, especially salt water enhances rusting because salt water is a better conductor of electricity. Heat, though not essential, accelerates rusting and let the reddish brown stain spread faster. Rust stain is very tough and only effective rust stain remover can clean it.

Rusting is a recursive process. When steel or iron begins to rust, the surface puffs up as the rust molecules are larger than those of iron. As a result, the surface flakes, cracks and opens up unaffected parts of the metal. Thus rusting goes on automatically and attacks the entire metal when the conditions are right.

All metals are prone to oxidation, but the main problem with iron oxides is the increased size of molecules. Metal oxides that are smaller than the metals do not flake or crack. Rather they form a protective layer on the surface and prevent further corrosion.

Iron oxide that forms during rusting is not smaller; however, the other oxide of iron, known as ferric oxide is! This oxide of iron is also called as black oxide because it is black in color. Black oxide or black rust does not swell, nor does it crack. It forms a protective layer on the surface as found in the metals like aluminum and prevents further corrosion.

Apart from destroying the structure, rust stain the metals with a reddish brown color. The parts become breakable and flimsy. When you touch a rusting iron, the loose particles come in to your hand and stain your skin. Same thing happens with any other substance that comes into contact with rusting steel or iron.

Rust cleaner can be used to remove stain and kill rust. Upholstery fabrics, wet clothes, carpet and curtains are few such things that often catch rust stain. Also, household things made of iron, automotive parts and precious articles can undergo rusting.

Sand paper can be used to remove rust from metal objects, but you need to scrub it hard until the entire surface is clean. Moreover, you cannot remove rust stain from crucial parts of an object.

Liquid rust stain remover simplifies the process. You need to spray it all over the surface and the stain will be dissolved eventually. Organic cleaners do not need to be neutralized after use and they have no side effects.