by Ron Joseph
February, 2005
Airless v. Air-Assisted Airless Spray Guns
Q. Kindly explain why air less gun is usefull for industrial application than
air assisted gun? Why one can go for air less spray gun for painting high solid
paints in in industrial application?
A. Both airless and air-assisted airless spray guns are used when you need
to apply large volumes of paint quickly. Both spray guns allow you to have high
fluid flow rates, and they can handle paints and coatings of high viscosity.
An airless spray gun is the only type of gun that can apply very high viscosity
coatings and even adhesives and this is because the fluid pressure can exceed
3,000 psig. Air-assisted airless guns usually do not exceed fluid pressures
of 1,000 psig and are therefore used for lower viscosity coatings.
In many cases, you can choose to use either an airless or an air-assisted airless
spray gun and be happy with the results of each gun. For safety reasons, I would
prefer to use an air-assisted airless spray gun because of its lower fluid pressure,
but if the coating viscosity is too high for this gun, I might no option but
to use the airless gun.
Because of their ability to apply large volumes of paint quickly, these guns
are usually not used to apply coatings for which you need to have a gook looking
finish. Therefore, you are unlikely to use an airless or air-assisted airless
gun when painting automotive finishes or high appearance items. HVLP and conventional
atomizing spray guns are used for these applications.
Be aware that the high pressures can be dangerous! Therefore, painters MUST
be properly trained to use these guns, otherwise they run the risk of being
injured. All spray equipment vendors of airless and air-assisted airless guns
provide safety instructions that painters MUST read and understand.
Best wishes,
Ron Joseph
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