A short overview with helpful spray gun tips about HVLP spray guns. DIY enthusiasts, craftsmen. automobile restorers and fabricators all agree that HVLP guns are great. There is a good reason why you will find a spray gun like this in nearly any spray shop on the globe, and below we will be explaining to you why with some helpful Spray Gun Tips. We have written this short spray gun tips article about the featured & benefits about HVLP spray Guns in general.

HVLP spray guns can be used by the amateur and professional alike, so this article will explain some pros and cons relating to the technology. This is a short overview of the benefits of HVLP spray guns compared to other technology. At Adendorff we stand by selling the right tool for the job, this saves our customer’s money long term.

What is a HVLP Spray Gun?

A standard Gravity Feed HVLP Spray Gun is used in a panel beating workshop.
A standard Gravity Feed HVLP Spray Gun is used in a panel beating workshop.

HVLP (high volume low pressure) means a high volume of material is displaced at a low pressure of air flow. This means that more of the paint propelled by the spray gun reaches the surface you are spraying with reduced wastage, overspray, and pollution of the air.

  • High volume = larger volume of paint material is displaced from the gun and makes it to surface
  • Low pressure = Reduced atomization of the material (less overspray, waste, pollution)

With these two features working together the result is a more professional finish and reduced cost of materials

HVLP Features

  • High transfer efficiency
  • Minimal bounceback
  • Sprays most materials
  • Reduced prep and clean-up
  • Affordable
  • Inexpensive to maintain
  • Controlled spraying
  • Portability
  • Reduces material consumption by 40%
  • Three spray patterns available
  • Cuts labor time
  • Sprays patterns from 1/4″ to 12″
  • Low fluid pressure means low wear
  • Moisture-free atomizing air

Problems with HVLP (not many don't worry)

HVLP spray guns cover less area than high-pressure types. But HVLP is better in nearly every other way.
HVLP spray guns cover less area than high-pressure types. But HVLP is better in nearly every other way.

There is actually just one downside to using HVLP spray guns and that is that they cover less area of effect than high-pressure guns and are slower to use if you are planning to spray large areas. This is due to the combination of high volume and lower pressure used. More material is heavier to displace thus spreading a smaller area. They are considered finishing tools.

Different Kinds of HVLP Spray guns

The most common type will be one that requires a source of air, most of our customers use air compressors for this purpose. The other type is an electrical airless spray gun that creates displacement with a built-in compressor, they are simply referred to as airless spray guns. Most professionals do tend to stick to the spray guns that use an external air compressor due to the benefits it provides.

Air Supply for HVLP Spray Guns

If you decide to go with the spray guns that need an air compressor there are some key things you need to understand. HVLP spray guns are great that they use less air flow than older guns but they do still need plenty, some people have this misconception that these new HVLP gun only need a tiny DIY compressor… wrong.

The reason you still need a large compressor is that of the duty cycle of the compressor. Most air compressors have relatively low duty cycles meaning they cannot run for hours on end unless its a commercial type of machine. You want a compressor to supply enough air that even while you are spraying you are using less air than the pump is supplying, because of this, the compressor will be able to have a rest period in between running cycles. HVLP air flow requirement differ from model to model but they are on the lower end of what spray guns tend to use. This information is referred to as CFM (cubic feet per minute) and you would want to aim for a compressor 25% above the CFM requirement of the gun for most use cases, 40% for commercial applications.

  • overshoot CFM on the compressor, not the spray gun.
  • you can spray with a small compressor it will work but you must wait for the machine to refill air pressure and the duty cycle of the machine will be exceeded.
  • make sure air filters are clean on the air pump and use water traps to keep the air flow clear of imperfections such as water or dust.

Benefits of HVLP Spray Guns

  • Less Overspray

Thanks to the higher volume of material being displaced more of it end up on the surface where the gun is being aimed. This means you will save money on paint by using less of it. HVLP is one of the most efficient types of spray guns you can get

  • Transfer Efficiency

HVLP is ahead in transfer efficiency. Less paint is wasted in the process and you get further with less paint.

  • Less mess

Less waste means a cleaner working environment. More paint makes it to the surface not the area around it. So more time is saved in clean up afterward

  • Environmentally friendly

Of course, masks should be worn as a precaution but with an HVLP spray gun, the sprayer would be exposed to less dangerous fumes from the paint material due to the high volumes being sprayed.

  • Precision

With different kind of touch up spray guns, the HVLP solution can be used for some very sensitive touch up spray work.

Popular applications for HVLP

HVLP Spray Guns are most commonly used when spraying car panels or smaller touch-up jobs.
HVLP Spray Guns are most commonly used when spraying car panels or smaller touch-up jobs.

The most popular industry for HVLP spray guns is the Automotive Manufacturing or repairs. You will find them in each body panel workshop on the globe. They are great for spraying most kinds of paints used on cars, on every coat too. The transfer rate and efficiency of the gun give it a very professional looking finish.

HVLP has a very broad use case and can be applied to nearly every spray job.

HVLP Applications Include:

  • Touch-up
  • Dentil molding
  • Crown moldingCabinets
  • Door Jambs
  • Elevator doors
  • Frames
  • Bi-fold doors
  • Implement equipment
  • Six-panel doors
  • Appliances
  • Porcelain
  • Furniture
  • Lockers
  • Shutters
  • Dividers
  • Gutters
  • General maintenance
  • Wicker furniture
  • Shelving
  • Pipes
  • Multi-color finishes
  • Louvered doors
  • Overhangs

How Does HVLP Spray Guns Actually Work

The paint container (being either gravity feed or suction feed) is placed under pressure forcing the paint material through the nozzle. A large volume of low pressure are is then intersected with the mainstream causing the atomization process.

The atomization process taking place inside the nozzle of the HVLP spray gun.
The atomization process taking place inside the nozzle of the HVLP spray gun.

Because of the lowered pressure, the atomized paint has less bounce back. Less overspray, greater transfer efficiency.

Illustration of particles and the resulting reduction of the bounce-back.
Illustration of particles and the resulting reduction of a bounceback.
Illustration of Adjustments found on most guns
Illustration of Adjustments found on most guns

Choosing The Right Nozzle Size

The nozzle size determines what kind of material can be sprayed by the spray gun. A larger nozzle size means a thicker heavier material can be used. A typical nozzle set includes the needle, air cap & fluid nozzle.

A spray gun nozzle, fluid nozzle, and air cap.
A spray gun nozzle, fluid nozzle, and air cap.

Below we will give some information relating to what kind of material is to be used with each nozzle size. Remember this is highly preference based and should only be roughly followed it also depends on the material manufacturers recommendations.

All measurements are in metric millimeter.

Varnishes (before low VOC)*.22.27thin materials
Lacquers, clear coats*.22.27
Shellac (clear)*.22.33
Stains – transparent.27.33
Water sealers (thin, clear).27.33
Tung Oil (pure thinned).27.33
Lacquers, waterborne*.30.35medium
Acrylics, clear*.30.35
Acrylics 100%, latex int.33.38
Varnishes (low VOC)*.33.38
Polyurethanes*.33.38
Stains – solid.33.38
Enamels – oil-base.33.38
Latex paint – interior.33.43
Latex paint – exterior.38.48
Primers – latex.38.43
Primers – oil.43.48
Heavy Latex.53.63thicker
Elastomeric (smooth).53.63
Elastomerics.63.99thick materials
Block Fillers.63.99

Conclusion

Thank you for taking the time to read our first article about HVLP spray guns. We strive to inform our customers with good information in order for them to get the right tool for the job. If you have any questions about HVLP spray guns or anything else please comment below or interact with us on social media. We will likely release more information that is more in depth relating to how to use the guns themselves and get that professional finish.

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