Note: An HVLP turbine is rated by the number of fans it uses to pressurize the air a three-stage unit has three fans, and so on. A three-stage system best balances the oomph it takes to spray most finishes with an affordable price. To find out which HVLP system to buy, we tested six three-stage models head-to-head, and also threw in a few two- and four-stage units for perspective. And these cups prove easier to set down when not spraying, although you might have to disconnect the hose on some models. Both work equally well when spraying, but we prefer the flat-bottom pressure cups for their smaller footprint and ease of filling with finish. Pressure in the latter cup forces finish into the gun’s airstream via the fluid tube, where it gets sprayed through the nozzle. ■ You can get both gun styles with either gravity-fed cups (mounted on top of the gun) or pressurized cups (beneath the gun). (We tested all the systems with nonbleeder guns.) Nonbleeder guns, our favorite, cut off both air and finish flow when you release the trigger. ■ Spray guns come in two styles: Bleeder guns pass air constantly, even when you stop the flow of finish. To offset this, most turbines have separate filtered intakes for spraying air and motor-cooling air. Although this warmed air all but eliminates moisture in the line, it also can cause finishes to flash-dry too quickly. ■ Because a turbine motor spins at about 20,000 rpm, it generates heat, which unavoidably warms the pressurized air. In order to be classified as HVLP, its air pressure cannot exceed 10 psi. Think of an HVLP turbine as a reverse vacuum pump: It sucks air through filters, then condenses and blows it through a hose to the gun.

Apollo hvlp spray gun parts