What Is a HVLP Spray Gun?

Painters often use HVLP spray guns when completing projects that require minimal overspray and a finer finish. These guns are of particular interest to furniture builders. The HVLP spray gun comes in two types: suction or gravity systems. Keep reading to learn more about different HVLP spray guns, how they work, and tips for using them.

What Does HVLP Stand For?

HVLP stands for high volume, low pressure. Spray guns that fall into the HVLP category include those that can prove a transfer efficiency of at least 65% when applying paint. Another way that spray guns get classified as HVLP is by measuring the PSI of the air at the air cap. To be an HVLP gun, it must be between 0.1-10 PSI.

Benefits of High Volume Low Pressure Spray Guns

When compared to completing paint projects with rollers or brushes, HVLP paint sprayers offer multiple advantages. For starters, these sprayers provide a much faster paint application process and result in a high opacity. Using these sprayers also results in fewer climbs up and down ladders for painters since they can provide large paint spreads in a single spray. Moreover, because the guns easily connect with various types of suitable accessories, you gain greater flexibility of movement, allowing you to complete projects faster and easier.

A lot of painters choose HVLP spray guns primarily because they don’t require you to move paint containers and buckets around. They also provide a great final result because the paint applies itself evenly with each spray. There is no need to perform any tedious cutting in of edges or corners with spray guns, either.

When To Use an HVLP Spray Gun

The number of coatings you intend to apply during a painting project will help determine whether an HVLP paint sprayer is best for you. If you want to paint with heavy or viscous types of liquids, an HVLP gun won’t be of much help. It’s also important to keep in mind that HVLP guns need a greater amount of air to atomize coatings when compared to a standard spray gun combined with an air compressor.

However, if your goal is to consistently produce lighter finish coats, an HVLP spray gun will prove valuable in a number of ways. HVLP gun systems require minimal maintenance, produce minimal waste, and give greater control over the final finish.

How Does an HVLP Spray Gun Work?

Paint sprayers that fall into the HVLP category have an onboard turbine that ensures the air power and paint do not mix until atomized at the very end of the nozzle. Some HVLP systems use a separate air compressor instead of an onboard turbine.

Keeping the air pressure and paint separate until the last point of spray allows more air pressure to build up, but at a lower pressure, thus minimizing overspray and giving the user ultimate control over the paint application. Customization becomes very simple with an HVLP spray gun because the user can easily tweak the volume and pressure of air and paint, thus making it simple to adjust the size of paint droplets and thickness of paint spreads.

Difference Between Airless and HVLP Systems

Paint sprayers considered airless don’t make use of an air mechanism as HVLP guns do. Instead of an air compressor or onboard turbine, airless sprayers use an internal piston pump that produces high pressure. This results in the material being pressurized directly with a lot of force.

Once the paint in an airless gun is pressurized directly, it makes its way through the hose attached to the spray gun before exiting the nozzle. The pressurized liquid then comes out of the nozzle, and the atomization takes place as it comes out against the spray tip; this results in lots of overspray because a high amount of pressure is needed to create the atomization. Most importantly, it limits your ability to provide details on the overall finish.

Because HVLP spray guns don’t require such high pressure, you gain greater control over the final finish without compromising your ability to perform detailed work. In fact, HVLP spray guns can be used for covering large and small surfaces that require a more detailed finish.

What Is the Best Paint Sprayer?

Standard spray guns generate substantially more overspray than HVLP systems because they release spray at a higher pressure. In addition to extreme material and product waste, this overspray can result in poor finishes.

HVLP sprayers provide smoother finishes and result in finer, more effective applications, and they come in two versions, suction and gravity, both of which have their own pros and cons. To choose the best paint sprayer for your job, it’s important to understand the differences between these two types of HVLP systems. A number of factors will influence which type best suits your next painting project. Such factors include things like your level of experience with spray guns and your preferred style of painting.

Suction HVLP Spray Gun

Suction guns lean more toward a traditional gun style with a paint cup connected directly to the underpart of the gun. The gun uses air pressure to suck the paint out of the cup, pushing it into the gun and out through the nozzle.

When compared to gravity guns, suction guns need quite a bit more air pressure. It is this need for higher air pressure that makes suction guns not nearly as energy efficient as gravity guns. However, the spray pressure of a suction gun can be easily controlled at the nozzle, allowing you to produce high-quality results. This is particularly true when the suction gun is combined with a turbine sprayer.

Gravity HVLP Spray Gun

In the 1980s, gravity guns first appeared on the market and quickly gained popularity among professional painters as well as seasoned DIYers. HVLP gravity paint guns rely on gravity’s pull to inject paint into the gun. A cup attached to the top of the pistol on the gun holds the paint. Minimal waste is achieved with a gravity paint gun because the gun uses all the paint in the cup thanks to gravity.

Gravity guns are a wonderful option for those projects where you want precision and maximum control. Why? Because the minimal air pressure needed to atomize the paint allows you to produce virtually no overspray.

Gravity guns work great for small paint jobs, but unless the materials are thinned, these guns make it difficult to work with heavier, thicker materials. Professionals who prefer to use two-pack paints — those made of an acrylic and resin hardener blend — frequently choose gravity guns.

Another major advantage of gravity guns stems from the paint cup’s design. Unlike a suction gun, which uses a traditional cup design that places the paint cup directly under the gun, a gravity gun situates the cup so that already painted surfaces are less likely to be touched or spoiled.

Uses and Applications of HVLP Spray Guns

There are lots of paint products that work with HVLP paint sprayers. They include:

• Chalk paints
• Oil paints
• Wood preservatives
• Wall paints
• Varnishes
• Primers

The materials that work with HVLP spray guns are often used to complete both indoor and outdoor paint jobs. Some of the most common applications for these guns are:

• Fences and railings
• Garage doors
• Furniture
• Garden objects
• Decorative objects
• Elevator doors
• Door jambs
• Six-panel doors
• Appliances
• Crown molding
• Gutters
• Wicker furniture
• Pipes
• Overhangs
• Ceilings
• Windows and doors

Tips for Using a High-Volume Low-Pressure Spray Gun

The results you can expect from spray painting depend greatly on the proper product setting and the best material dilution. The ideal spray result should have clean borders and no discernible color spots.

The sprayer, its various setting options, the substance being sprayed, and your spraying style all play a role in the final result. This is why you should always read an HVLP gun sprayer’s operating instructions before using it. Reading through these instructions will also help you follow the manufacturer’s recommendations for the correct dilution of the painting material you choose.

Use a Large Air Compressor

When painting with an HVLP gun, make sure to use it with a large air compressor. In doing so, the gun doesn’t have to rely solely on its internal built-in air supply. This translates into less wear and tear on the spray gun and also makes it easier and faster to apply coats of paint. It also extends the longevity of the gun itself.

Choose the Right Tip Size

The efficiency and effectiveness that you can achieve with an HVLP gun mostly depend on the size of the nozzle you choose. The bigger the nozzle, the thicker the painting material you can use. Thin painting materials can easily be applied using smaller nozzle sizes.

Most of today’s HVLP spray guns come in a kit package. The kit includes all the parts you need to use the gun, minus the paint.

When choosing which tip to use on the HVLP sprayer, keep these helpful tips in mind:

• When you buy a standard HVLP spray gun, it will likely come with a tip ranging from 0.5 mm to 1.0 mm. This size spray tip helps keep the spray amount to a minimum while still allowing you to paint areas with precision.
• If your painting project requires applying a thin coat of paint that provides almost a see-through effect, then a tip size of 1.2 mm to 1.3 mm should work well. This size tip is especially useful when applying base coats.
• When using an HVLP gun to paint cabinets, note that paint, in all applications, goes through multiple stages to achieve the final finish. Cabinets usually require applying a thick coat of paint, which HVLP guns are not known for. However, if you use a 1.4mm tip, you should be able to achieve the thick coat finish you want.

Tip sizes ranging from 1.5-1.8 mm are ideal for applying single coats of paint. They are used mostly for applying a base coat or primer.

Check the Droplet Size

Large droplets will result from too much air pressure and will take longer to dry than small droplets. Therefore, to ensure correct application, it’s wise to check the droplet size and adjust the air pressure to suit your project.

You can check the droplet size by spraying an old piece of glass, metal, or wood. Start by setting the air pressure as low as it will go. You can then increase the air pressure in 5-pound increments until you achieve the desired droplet size. The goal is to adjust the air pressure until the gun produces a consistent, uniform color.

Clean After Each Use

It’s important to check the air filters each time before using an HVLP sprayer. You can easily clean them with soapy water and then let them air dry. To clean the air pump on the gun, simply run cold or warm water over it to remove any dirt, dust, or debris.

To enhance the durability of an HVLP spray gun, make sure to perform regular maintenance and care. You can read through the product’s owner’s manual to find helpful maintenance advice.

Additionally, take a solvent to clean the air cap and get rid of the color you’re painting with after each use. If you have time, it’s extremely helpful to take a gun cleaner to clean the entire spray gun after using it each time.