Gradually oxidized when metal comes into contact with oxygen. Some acids accelerate the oxidation with rain and sea water. We call it rust. However, rust (corrosion), as a matter of fact, is not so trivial. Rust breaks resistance of metal and causes to its decay. When any item made of iron and steel decays, it becomes useless after a period of time. Therefore, it is important to prevent contact of materials with oxygen in order to use the materials we have for many years. There are various ways to do this:

1)    By facing the material with chromium (as it is a very expensive method, it can be applied simply to small subjects.)

2) Material should be painted. (Today, it is the simplest and the most economic method being applied all over the world)

 

PAINTING WORK

The most important work to be done before painting an object made of metal is to clean the surface, – where paint should be applied -, from grease, rust, concrete and paint remains.

The most ideal surface treatment applied to an object made of metal is to make sanding. Polishing or cleaning with a wire brush on small parts can be effective; however, these two methods compared to sanding are extremely insufficient too. Additionally, polishing or brushing method on big parts is laborious and useless.

WHAT IS SANDING?

It is a method used for the purpose of cleaning metal structures from rust and other substances; this method is also used in order to provide a more rigid adhesion of paint to the surface. It briefly means that it is an abrasive blast cleaning method with an erosion of certain subtle surface formed as a result of sand blasting onto the surface through the high-pressure air  (through particles of different sizes). It is measured by different standards. Sanding is mainly applied in accordance with the standard SA 2.5.

SANDING MATERIALS

Steel shot: they are metal particles in the form of relatively round cuttings compared to grit. They can be in various sizes and fractions. They can be mostly used. However, they are ten times more expensive than grit material in terms of their price.

 

Grit: It is a sand material which pollination or dusting is the least and sanding power is the best. Its composition consists of small metal fragments.

SANDING EQUIPMENT AND SANDING PROCESS

Sanding work is carried out by means of a high-pressure air compressor which is a mobile sanding machine, as well as by means of hoses and other secondary equipment. A person who implements sanding work must absolutely wear a special diving suit and a special uniform.