Today we take the notion of spray painting for granted and it is a process used in all of our cars, trucks, even aeroplanes. Spray painting with compressed air has been around since the 1880’s, when it was generally used for spraying whitewash onto walls, which was significantly faster than doing it in the more conventional manner with brushes. It was only after the Second World War though, that aerosol paint was introduced to the market, which has never looked back since. Spray painting involves paint being applied through the use of an air pressurised spray gun, which when triggered mixes the paint with the pressurised air and is released as a fine spray. The process is very flexible and a number of different paint consistencies can be achieved through the use of varying size and shaped nozzles. The two types of air gun spraying processes either employ a skilled operator who applies the paint from 6-10 inches from the object in a back and forth motion to ensure a continuous coat, while in an automated process, the gun delivers the stream of paint from a mounted position.
Different Options and Technologies
Spray painting has far more complexities that just firing paint and compressed air out of a spray gun though, with differing levels of air pressure and paint volume being used, to allow a higher volume of paint to be applied to the surface. This reduces material consumption and any excess paint in the air, which can cause what is known as overspray, as it lands on unwanted areas. Electrostatic paint spraying was discovered in the late 1940’s and works by electrically charging the paint particles and applying an opposite charge to the surface to be painted. The paint is then attracted to the surface, which produces a more even coat, reaches hard to get to places, reduces the amount of paint required and is often used on car panels and motorbike frames. Heavy duty industry sometimes uses an airless spray gun, where the paint itself is pressurised and provides for the use of less thinners, which reduces drying time, allows for thicker coats to be applied, reducing the amount of coats required and gets into every nook and cranny. Extreme caution should be used with this type of spraying as there is the potential for serious injury, given the high pressure at which the paint is expelled.
The Spray Booth
Found in pretty much every decent car repair shop, the spray paint booth is a pressure controlled, closed environment, which is able to deliver the perfect working conditions for paint delivery. It gives the precise humidity, air flow and temperature, and removes through an exhaust system toxic solvents and excess paint, generally after filtering and treatment to prevent outside air pollution. They are equipped with purpose designed ventilation and sometimes with burners, to heat the air and speed up the drying process. Additional systems are often utilised to assist in the extraction of excess paint in the air.
Spray booth manufacturers today are able to provide highly technologically advanced units, which can provide the optimum working environment, maximise workspace and improve drying times remarkably, and can be installed either inside or outside your working premises.