Buyers Guide to Spray Guns
Below you will our guide to choosing the right spray gun to meet your needs. From selecting the right fluid tip sizes to choosing the correct paint feed system you will find all theses questions and more answered below.
Fluid Tip Sizes
In general the thicker the viscosity of the paint, the larger the fluid tip size needs to be.
Spray guns with 0.5mm to 1.2mm are generally used for spot repair/touch up work. Fluid tip of 1.3mm to 1.6mm are used for general body shop spraying on car panel and 1.8mm sizes and above will spray most automotive primers.
Gravity Feed Spray Guns
Gravity feed guns use less air pressure to deliver the paint because it doesn’t have to draw the fluid up and therefore is more efficient on the air supply. Gravity feed models will also use every drop of paint in the cup and are excellent for spraying in tight spaces where a siphon/suction gun may accidentally touch the painted surface. Also gravity feed guns have semi-transparent cups so you can see when you are running low of paint thus avoiding the risk of paint-flow interruptions.
Suction Feed Spray Guns
Suction or Siphon feed guns usually are fitted to spray guns that have larger fluid tips and carry more fluid than gravity feed models. The cups are generally make of metal and have the advantage of being able to set the spray gun down anywhere without the need of a spray gun holder.
Pressure Feed Spray Guns
Pressure in this system is provided by an external source such as a pressure tank, through a hose. Pressure-feed guns are used in in large industries applications where vast amounts of paint are to be sprayed. The air in the cup also may be pressurised, which in turn forces the fluid to rise through the dip tube in the cup. Air atomisation is achieved using a separate air hose.
Air Caps
On a spray gun the air cap is the part that does the real work. It has precision-drilled holes that are carefully placed to produce a certain atomized spray pattern on the surface to be painted. Air entering these holes not only atomizes the paint but also creates the shape of the fan.
Click on the image below to download a PDF file showing the different DeVilbiss air caps and the applications they are most suited for