An airless spray gun is used for painting surfaces. It is a component of an airless paint sprayer system, which includes a pump and a fluid-supply hose. The term "gun" is used for the device because its appearance resembles a handgun. An airless spray gun can provide more convenience and greater production than painting with a brush.
Background
There are two types of airless spray paint gun: two- and four-finger. The figures indicate the number of fingers required to pull the trigger. Choosing the type of airless spray gun depends on the user's personal comfort, needs and expectations. Airless spray guns are used by contractors and heavy-equipment operators to paint buildings, houses, bridges and other big structures.
Parts
Airless spray guns come in different designs, depending on the model and manufacturer. However, regardless of design, the device will always have principal parts such as spray tip, gun body, fluid inlet, fluid valve, trigger, trigger lock and tip guard. The spray tip controls fluid-flow rate and creates back pressure. The body is the frame for the internal parts and handle for the operator. The fluid inlet provides attachment for the hose. The fluid valve regulates the fluid flow. The trigger is used to mechanically open the valve. The trigger lock prevents the trigger from being accidentally pulled. The tip guard serves as protection from skin injection injury.
Process
The airless spray gun works on the principle of using high pressure to release paint fluid, which causes atomization. Under high pressure, fluid comes out of the gun's spray tip as a narrow sheet. Fluid and air create a friction that breaks this narrow sheet into small droplets. To begin the process, paint fluid is pumped into the gun and flows through the hose. The fluid enters the fluid inlet. The spray gun's fluid valve controls the flow of the liquid. When the trigger is pulled, the valve opens to allow the fluid to flow under pressure toward the spray tip. When the trigger is released, the fluid valve closes.
Advantages and Disadvantages
Airless spray guns use a high volume of paint fluid to enable a fast spraying process. Another advantage is they don't need much air, which limits fogging and eases spraying into narrow openings. However, the device can overspray because of the high volume and lack of control on regulating the output; superior operator skills are required on smaller parts. The spray tips and the pressure pump can be expensive. Too much atomization causes runs on the paint surface. The equipment also requires high maintenance because high-pressure fluid wears out the parts quickly.
Safety
High-pressure spray can splash into the eyes or inject toxic fluid into the skin, causing serious injury. Operators must exercise safety precautions when using the device. Do not point the gun at any part of your body or at someone. Never put your hand over the spray tip. Do not try to stop leaks with hand and body. Always check that safety devices are working properly. Read the safety manual before using the airless spray gun.
