Conventional Spray Gun Function

• The standard spray gun apparatus consists of an air compressor connected via a pipe to the actual gun. The gun consists of a paint basin, a nozzle and a trigger. When the trigger is depressed, the compressed air mixes with the paint and spray is emitted from the nozzle. Sometimes the compressed air is held in a can attached to the spray gun. There are a number of different methods for turning a stock of paint into the tiny droplets that make up the spray. This process is called "atomization." The first and most basic method simply uses compressed air and paint.
  
  

HVLP and LVLP

• HVLP stands for High Volume Low Pressure. HVLP is a spray-painting method that uses a lower than normal pressure and higher volume of air than standard spray guns. These means there is less "overspray" and more paint reaches the target surface. An alternative to HVLP is LVLP. LVLP stands for Low Volume Low Pressure and has a similar effect.
  
  

Electrostatic

• Electrostatic spray guns use an alternative method to spray the object. The "paint" is a fine powder that is electrically charged. The object to be sprayed is charged with the opposite polarity. The powder is then drawn to the object. The object is then baked in order to attach the powder to the object. Electrostatic spray guns are good for even application on complex metal objects, and as such are widely used to paint car parts.
  
  

Spray Gun Usage

• There are several general pieces of advice when using a conventional spray gun. Always wear goggles to avoid spray making contact with eyes. Wear appropriate clothing. You may be able to adjust the shape of the spray. The cone of spray can be narrowed by turning the air control knob clockwise, and widened by turning it anticlockwise. Hold the spray gun around 8 to 10 inches from the object or surface to be painted.
  
  

Spray Gun Problems

• Intermediate spitting can result in uneven paint coverage. This is usually caused by a dried out packing ring, which lets air into the fluid flow. Take the nozzle apart and drop a small amount of machine oil onto the packing ring. Wipe the fluid tip with with a rag and paint thinner. Another spray gun problem is spattering, where you get an uneven spray. Alter your air pressure to alleviate this problem. An unsymmetrical spray pattern may be caused by a blockage in an air hole. Clean the nozzle with a rag and paint thinner as with the intermediate spitting problem.