In the alphabet soup of construction terminology, HVLP is one acronym that you may not be familiar with. However, if you’re looking for a simple way to apply a wide variety of finishes to a wide variety of surfaces, they’re four letters you might want to get to know a little better. HVLP stands for high velocity, low pressure, and the new generation of HVLP sprayers offer one of the easiest, most effective methods for spraying paints, stains, sealers and other finishes.
Conventional air-powered paint sprayers utilize an air compressor to generate the air they use for spraying. In the process of compressing air, moisture builds up in the compressor tank which is then introduced into the air stream, and consequently into the finish being applied. They also apply finishes at a relatively high air pressure, which makes for additional overspray and wasting of materials.
With HVLP, a specialized air turbine is used to move the air, which is delivered to the spray gun through a relatively large diameter hose. No air storage tank is utilized and the air is not compressed, so moisture is not a problem. Also, the air turbine generates air that is not only dry but also warm. The warm air may help marginally with the drying time of the finish, particularly on days when spraying conditions are not ideal, and after cleaning the spray gun, the warm air can be helpful for drying the components of the spray gun itself.
HVLP turbines produce a high volume of air – anywhere from 50 to 100 cubic feet per minute (CFM) – at a very low delivery pressure of only four to seven pounds per square inch (PSI). This combination of high air velocity and low pressure is the opposite of conventional compressed air spray outfits, which deliver a lower volume of air at much higher pressure. The result – and one of the primary advantages of the HVLP sprayer – is much less overspray and a much higher percentage of the finish material actually reaching the surface you’re spraying. Some manufacturers estimate that overspray is reduced by as much as 85 percent.
HVLP sprayers are excellent for applying paint, stain and other finishes on cabinets, machinery, woodworking projects, furniture, and much more, as well as interior wall and trim painting. They are not intended for continuous use, however, so don’t plan on painting the outside of your house with it.
While there are now HVLP spray guns on the market designed for use with conventional air compressors – known as conversion guns – true HVLP sprayers consist of three separate components that all work together. These include the turbine; the HVLP spray gun, which looks similar to a conventional spray gun but has a different internal design; and a flexible, large-diameter hose that connects the two.
Heavy-duty dedicated HVLP sprayer rigs cost around $700 and up, so until fairly recently this form of spraying was confined primarily to professional shops. However, there are now medium-duty HVLP spray outfits on the market designed with the homeowner in mind, with attractive price tags and equally attractive performance. For example, Campbell Hausfeld has introduced their HV2000 series, which includes everything you need for HVLP spraying with great results, at a price tag that is under $200!
The complete HV2000 outfit weighs in at only 15 pounds, and is designed as a complete and convenient spray package. The turbine has a round well that holds the spray gun when not in use, the electrical cord and 15-foot hose wrap around the turbine housing, and there is a built-in carrying handle that makes it a breeze to transport the sprayer from project to project. Tools, strainers, and complete gun and turbine instructions are included as well.
Effective spraying with an HVLP is a combination of proper material thinning, proper airflow and proper application technique. The HV2000 instruction manual offers clear instructions on each, and it takes only a short amount of experimenting to get very good results. And since the finishing material is contained completely within the gun during spraying operations, cleanup is surprisingly quick and easy as well.
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