Spray Painting

Spray painting is a type of coating technique which is more and more commonly used on various surfaces especially metals and requires a spraying device like a spray gun to spray a specially formulated coating for example paint, varnish or ink through the air onto a surface. Such spraying application requires the choice of spraying equipment to be determined as well as the type of paint to be applied.

The most common type of spray painting utilized spray guns employing compressed gas or air to atomize and converge the paint particles onto a particular surface area. Hence depending on the area to be applied, spray gun that is used is generally larger than airbrushes which could be handheld for detailed work like photo retouching, painting nails or fine art which is not suitable to be applied for industrial facilities that cover a big surface area. Due to the suitability of the spray coating system, air gun spraying utilized equipment that is generally much larger so as to cover larger surfaces to produce an even coating. The spray guns being used could be either automated catering to different types of surfaces or manually operated involving interchangeable heads for different spraying patterns. Moreover, paints stored in single colour aerosol cans are portable and convenient to carry which does not pose too much burden for spray coating to be carried out.

The different types of spraying coating are:

• Air gun spraying: This type of spray coating can be categorised to HVLP (high volume low pressure) and LVLP (low volume low pressure) where the difference can be observed in the transfer efficiency and the amount of compressed air consumption.
• Electrostatic spray painting: Such spray coating requires the paint (liquid or powder) to be electrically charged before spraying is carried out. Meanwhile, there are mainly three technologies invented for charging the fluid which are direct charging, turbo charging and post-atomization charging.
• Airless spray guns: The advantages of using this technique are coating particles are better sprayed into crevices or small fissures, an even coating of spray paint could be produced and good adhesion coating could be obtained.

When using spray coating systems for rust and corrosion resistant purpose, the parameters of the spraying equipment should be determined prior to application and the standard of pressure and nozzle should also be confirmed according to the recommendation of the spray coating contractors. This is because a careful planning of the suitable usage of spray painting can save costs as well as improve coating efficiency.