Rust is the product of the chemical reaction between oxygen in air and metals, such as iron and steel. It is formed because oxygen atoms (O-2) have a net charge of -2 and iron (Fe+3) has a net positive charge of +3. Therefore, in order for the chemical reaction to produce rust or iron oxides through oxidation, two iron atoms will chemically react with 3 oxygen atoms. The molecular combination will look something like this: (O-2) 3 + (Fe3+) 2. The sum of the charges of this molecule or atomic combination is zero, which makes it a stable unit or molecule. In nature, that is exactly what a molecule of rust looks like when moist or salty atmospheric air containing oxygen, comes in contact with metal surfaces that haven’t been treated with protective coatings of metal paints or anti rust primers. So, how do we get rid of rust when it is formed on metal surfaces in our home?
There are several ways of coating metal surfaces to prevent oxygen damage or reactivity. A common method is painting metal surfaces with metal paints or anti rust primers. There is the traditional method of using abrasive tools to scrub the rust away. Other methods treat the rust itself by converting it into nondestructive forms. A very common metal paint that does exactly that is the Rust Doctor. It works by converting rust (iron oxide) into magnetite, a common black magnetic mineral consisting of iron oxide. After it converts rust into magnetite, it prepares the surface of the metal for painting with other types of metal paints. This will work with metal surfaces that are indoor and outdoor.
In regards to how indoor and outdoor exposure relate to rusting is that outdoor metals will rust faster as a result of continued exposure to moisture (water in air) and salt in the air as opposed to indoor metal surfaces, which very rarely get exposed to moisture or salty air.
The best approach is to prevent Industrial Paint metals from becoming rusty in the first place, so resources don’t have to be expended in order to get rid of rust. Metal furniture or other items should be coated with metal paints or anti rust primer finishes before they are exposed to air. Rust will eventually cause a metal item to completely disintegrate and disappear if nothing is done to stop its progression.
The first sign of rust spots on metal surfaces should be addressed immediately. There are some ways to get rid of rust spots before they become full-blown rust–a regular steel or wire brush accompanied with sandpaper and phosphoric acid will normally do the job if rust formation is suspected. Under some circumstances, more than one cycle of scrubbing with the aid of phosphoric acid will be needed to completely get rid of rust. The phosphoric acid converts rust into ferric phosphate (FePO4), which is black in color. This ferric phosphate can either be rubbed off leaving a fresh surface on the metal or be left on. If left on, this process forms a protective coating on the metal surface, which prevents it from rusting again in the future. Anti rust primers should be used to prevent rust formation in the future and to get rid of rust. In fact, any metal paint can be used to paint metal surfaces coated with anti rust primers.
In summary, rust forms when metal surfaces are exposed to oxygen in air, esp.