How a spray gun works

In just a few words, the spray of coating happens when the paint is applied to an object (the surface to be painted) through the compressed air gun.

When the trigger is pressed, the paint mixes (although in some systems it does not mix) with the compressed air stream and is released in a fine spray.

The consistency and pattern of paint can be defined and regulated by the correct use of the cup or tank where the paint is placed, and the nozzle that is chosen.

Regardless of the type of technology used to paint, it is extremely important to frequently disassemble the nozzle of the spray gun to clean it and prevent it from becoming clogged with traces of dry paint. 

Advantages of spray guns

Allow paint to be applied uniformly on the surface

Allows different types of surface (even irregular or rough) to be painted efficiently

Save time and production costs

Can be configured for automated use

There is good diversification for specific applications

There are different ways to configure each gun according to the need of finishing 

Parts of a spray gun

The spray guns are divided into these basic parts:

Air head

Flow regulator

Nozzle or peak

Tank (depending on its type the gun can have a deposit or be connected to a tank)

Air head

The air head is, perhaps, the most important part of the spray gun.

This part of the gun directly affects the quality of the result and the amount of paint used.

Depending on the type of gun, the mixture of air and paint can happen internally or externally. 

Flow regulator

It is the piece that determined how much paint will come out through the nozzle and even allows to vary the shape of the paint jet.

It is usually located in the handle or trigger.

The very tight restriction of the flow regulator is not good practice.

It has happened that the operators close the flow regulator a lot and with the force of the hand, exert a very large pressure on the trigger, which is transferred to the flow regulator, opening when the trigger is pulled.

This force deforms the flow regulator and generates drips.

It is better to adjust the flow from an external source such as the fluid regulator or restrictor and not the gun.

In this way, the flow regulator will be only to activate and deactivate the painting flow.

The nozzle

It is where the paint is expelled. Many spray guns come equipped with several interchangeable nozzles, so the operator can choose the one that is appropriate according to the case.

Some brands of spray guns, such as Binks and Devilbiss, even have extensions to get hard to reach places.

Although there are more than 15 types of nozzles available in the market, the 3 most used in industrial finishing processes are those of these spray technologies:

Low Pressure Aspersion

Airless

Airless Air Assisted