HVLP and Airless Paint Sprayers
In an HVLP, air pumped from an air compressor or turbine atomizes paint. In an airless sprayer, a piston pressurizes the material, which sprays out of an orifice smaller than that found on an HVLP nozzle. The high pressure and tight squeeze shear the paint into particles.
by John Strieder
market airless paint sprayers alongside air-pumping HVLP sprayers. They think you should buy one of each.
“I’ve been preaching this story for 20 years or more,” says Tony Torntore Sr., director of training at Wagner Spray Tech Corp. “I believe in my soul a contractor needs an airless unit coupled with an HVLP. He needs three pieces of equipment — a pressure washer, an airless and an HVLP. He can go out and make a living with those three.”
In an HVLP (which stands for “high volume, low pressure”), air pumped from an air compressor or turbine atomizes paint. In an airless sprayer, a piston pressurizes the material, which sprays out of an orifice smaller than that found on an HVLP nozzle. The high pressure and tight squeeze shear the paint into particles.
Airless sprayers are designed for big, relatively flat surfaces, such as walls, oil tanks, garbage bins and siding, Torntore says. HVLPs, in contrast, are for fine finishes and situations where a contractor wants more precision, such as handrails, doors, cabinet work and window jambs. “An HVLP is a substitute for a brush. An airless is a substitute for a roller,” he says. “They’re actually complements for each other.”
Airless units have a product transfer rate of only 50 percent, while HVLPs can achieve up to 90 percent, Torntore says. But airless units are also more powerful.
They can achieve 1,700 psi at the nozzle, compared to 10 psi from HVLP units, says Rick Soto, director of marketing and sales for HVLP maker Benron Equipment & Supply Inc. “You’re talking two different animals for two different types of spraying. HVLPs are more fine production, not high production.”
Unlike airless spray guns, HVLP guns have a second control knob that regulates air flow, giving the user more control over the fan size. There is less overspray, making HVLPs a good choice when working with expensive paint. “With an airless, $100 a gallon lacquer is just going to blow out everywhere,” Soto says.
And an HVLP finish simply looks better, says Gary Schwebemeyer, distribution sales manager for ITW Industrial Finishing, makers of the DeVilbiss and Binks lines. Atomized particles from an HVLP unit are smaller and more uniform than particles propelled from an airless sprayer, he says. With latex wall paint on drywall, the difference won’t matter. But when working with varnishes, stains or enamels, the finer, smoother finish is noticeable, he says. Otherwise, painters may contend with the dreaded “orange peel,” a surface with a mottled, textured look instead of a satiny finish.
HVLPs are also handy for doing touchup work, Soto says. “If contractors have already cleaned up their system and put it away, they always have something they can go with. It’s easier to refill and clean up a quart cup than refill an airless and bucket.”
But airless units are better for high-volume jobs, such as the exterior walls of a house. Airless units will finish off a can of paint at a rate of one half gallon to two gallons per minute, much faster than the HVLP’s pokey rate of 15 or 20 ounces per minute, Schwebemeyer says. “Speed is a big factor. You can fly with an airless.”
And airless units can handle more coatings with less fuss, says Chris Noto, electric sprayer product manager for Titan and Spray Tech products, both made by Wagner Spray Tech. When using HVLPs, a contractor may have to reduce the material’s viscosity, he says. “With airless, just about all you do is put the tube in the bucket and go. It just sprays it straight.”
Coarse grinds, such as flat or enamel latex paints, do not work well with HVLPs, Torntore says. They are made to be brushed, rolled, or sprayed on with airless units. “The finer the grind, the more that paint is conducive to spraying.”
There are also differences in cost and performance between turbine HVLPs and those hooked to an air compressor.
Turbine units, which run like vacuum cleaners in reverse, are more portable than compressor models. Also, their heated air can speed dry times, Torntore says. “It’s so much easier to just take a turbine unit and plug it in. That’s what made the business what it is today.”
But compressor machines offer more versatility in varying psi output. And when spraying fine lacquers, cold compressed air works better than heated air from a turbine, Soto says. “There’s so much difference in the finished texture. Once you run the two side by side, yes, you can tell.”
The two kinds of HVLPs may also have different capabilities when it comes to producing finer sprays. “Compressed air models shouldn’t have any problems achieving fine spray,” Schwebemeyer says. “A turbine will, or is susceptible to those kinds of problems.” If fine spray is an issue, a contractor must strain the paint, thin it, or reduce flow rate.
HVLPs with compressors cost more than the cheapest airless units, but less than high-end units, Schwebemeyer says. And they are generally more expensive than turbine units. However, many contractors already own a compressor for powering nail guns and sanding tools, he notes. All they need to buy is a spray gun and other accessories.