How to Set Up an HVLP Spray Gun?

HVLP spray guns provide smooth, even coverage, with a minimum of overspray. Whether you’re spraying stain, paint, lacquer, or something else, use this article to get your HVLP spray gun properly set up. I’ll also teach you how to make adjustments to an HVLP spray gun if it’s not working the way you expect. 

Setting Up an HVLP Spray Gun

To set up your HVLP spray gun, follow these steps. 

1. Set the pressure. HVLP stands for high volume, low pressure. Many HVLP manufacturers advertise that their machines operate at between eight and ten PSI, but this is measured at the air cap using a special gauge. A PSI between 25 and 30 is appropriate for most HVLP spray tasks and will give you eight to ten PSI at the air cap. 
2. Set your fan control. For small, detailed work, tighten the fan control knob. For covering larger surfaces, loosen the fan control knob. Test your fan spraying by holding the gun steady and aiming it at a scrap piece of cardboard. Squeeze the trigger for a few seconds, observe the pattern the paint makes on the cardboard, and adjust the fan accordingly. 
3. Open the fluid volume control. How much you loosen the fluid volume control knob is a matter of personal preference. However, you must loosen it somewhat, or your spray medium won’t flow through the fluid needle and you won’t get any spray. Experiment with different fluid volume levels and find which one works the best for the material you are spraying. 
4. Set your air volume control. The best way to set up an HVLP spray gun is to purchase a regulator than can be attached directly to the air inlet. By leaving the air volume control completely open and using an additional regulator, you have total control over air flow levels without needing to adjust the regulator on the compressor. 
5. Connect the hose. Connect the regulator at the bottom of the spray gun to one end of the air hose. The other end of the hose connects to your air compressor or turbine. 

HVLP Spray Gun Controls

There are three knobs you will see on all good HVLP spray guns. The location of the knobs changes from one model to another, but there are some general rules. 

• The airflow control knob is usually located on the bottom of the spray gun, next to the air intake. 
• The fluid volume control knob is usually located on the back or side of the spray gun, in line with the nozzle. 
• The fan control knob is usually located close to the top of the spray gun. 

Airflow Control Knob

The smoothness and evenness of your paint coat is dictated by how much air flows through the spray gun. The air volume control interacts with the pressure regulator to control the flow of air through the spray gun.

Fan Control Knob

‘Fan’ is a word used to describe how wide the spray of paint is. When the fan control knob is tightened all the way, the spray gun pattern will be a tight circle. If the fan control knob is loosened all the way, the spray gun pattern will be shaped more like a football. 

Fluid Volume Control Knob

The fluid volume control knob controls how far the fluid needle will move when you squeeze the trigger. If the fluid volume control knob is tightened all the way, no paint will come out. 

Read my Woodworking HVLP Spray Gun reviews to find the best one for your project.

How to Adjust an HVLP Spray Gun

Once you’ve set up your HVLP spray gun, you may have to make minor adjustments while spraying. 

• If you can’t squeeze the trigger, or there is no paint coming out of the nozzle, open the fluid control knob. 
• To move from a large surface to detailed work, tighten the fan control knob. 
• To move from detailed work to coating a larger surface, loosen the fan control knob. 
• If the paint is dribbling out, adjust your air volume control knob or adjust the pressure directly. You may also need to thin your liquid before it can be sprayed. 
• If the paint is spitting, stop spraying. Take the nozzle off and check that your fluid needle and air cap are properly configured and that there are no blockages in the system.

Conclusion

HVLP sprayers must be set up properly to get the smooth, fast, even coverage they are known for. Purchase a spray gun-mounted pressure regulator for easy setup and adjustment. The three main controls on every spray gun are; fluid volume control, air volume control, and fluid volume control.