How to Adjust an Airless Paint Sprayer

Turn the pressure control knob counterclockwise to the lowest setting before plugging in and flushing the airless sprayer. The pressure control knob is usually on top of the motor housing and can be turned by hand. All sprayers are stored with mineral spirits in the pump and need to be flushed before starting to paint.

Flush the mineral spirits with water or solvent (if using solvent-based material) and place the pickup tube and siphon in your paint bucket. Push the prime valve until it's pointing straight down in the open position. The prime valve is a lever, usually on the side of the motor housing.

Trigger the spray gun into the bucket and allow the paint to flow until it is running smoothly without spitting or bubbles. Turn the pressure control valve up -- for most paint it should be turned about 2/3 or a turn clockwise. Thinner materials, like stain and varnish, require slightly lower pressure. Install the spray tip, and you are ready to paint.

Increase the pressure a little if the motor runs but does not build pressure or if paint won't come out at all, or comes out in a thin, weak spray. decrease pressure if the paint comes out with such force that you feel it "kicking" your hand back, or if it applies the paint too heavily in an uneven spray pattern.

Change to a new spray tip if no matter how you tweak the pressure, you cannot get the paint to flow in an even spray pattern without runs or spattering. Spray tips are replacement parts and can wear out quickly with some materials such as latex paint sprayed at high pressure.

Repeat steps 2 and 3 if the airless sprayer continues to be slow about building up enough pressure to spray.