Use HVLP equipment for a fine finish.
HVLP stands for high volume, low pressure, and refers to a type of spray application. HVLP spray guns are highly efficient when compared to older spray equipment that used higher air pressures. HVLP guns typically operate with cap pressures as low as 15 PSI, compared to traditional equipment that had pressures in the 60 PSI range. The lower pressures lead to more efficient transfer rates, since less paint bounces off the piece being sprayed. The bottom line is HVLP guns use less paint to cover a given surface area.
Instructions
1. Thin the paint for spraying. The required consistency will depend upon the spray cap being used; spray caps are sized in millimeters, with a typical range of 0.8mm to 2.5mm. The larger diameter tips are for thicker materials such as primers or latex paints.
2. Pour the thinned paint through a paint filter into the HVLP gun's paint cup. Filtering is an important process; even small contaminants in the paint can clog the gun.
3. Adjust the compressor's regulator. HVLP guns vary, but if you don't have an instruction manual for your gun, start with 25 PSI, but be prepared to go as high as 45 PSI.
4. Hook the air source up to the spray gun. It's a good idea to put an air filter in the line between the air hose and the spray gun. If you use a quick disconnect fitting, make sure it has a flow rate that matches the gun's requirements.
5. Begin spraying. To adjust the gun, spray a test pattern on a piece of cardboard or other scrap. Adjustments on most automotive type HVLP guns are similar. The knob on the base of the handle (near the air inlet) controls air flow. The knob on the back of the gun controls the paint flow, and the knob on the side of the gun selects the pattern. The spray cap on the front of the gun can be turned for a horizontal or vertical pattern.
Start spraying by pulling the gun's trigger, and then moving the gun over your work. Continue sweeping the gun in front of your work piece, about 8 inches from your work. Sweep beyond the end of your work, and then release the trigger. Continue in this fashion, overlapping each pass by 50 percent.
6. When you are done painting, clean the gun immediately. Rinse out the paint cup with thinner. Then spray clean thinner through the gun until it comes out clear. Remove the spray cap and inspect it for cleanliness. If the spray cap isn't clean, soak it in thinner to clean it.
