Intro to Airless Paint Spraying

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In 1958, Graco invented portable airless spraying. This innovative process for spraying paint is more popular today than ever before thanks to continuing advancements in technology and how the different types of airless spray delivery methods have been improved over time on job sites around the world.

Since the technology was introduced over a century ago, professional contractors have preferred airless paint spraying for many reasons:

Airless spraying increases speed. Airless spraying is faster, so more jobs can be completed in less time, using less labour – plus, it’s great for jobs with a short weather window.

Airless spraying improves overall finish quality. Airless sprayers produce an even coat of paint (referred to as the mil build) on all types of surfaces, leaving a high-quality finish.

Airless spraying is also very versatile. Airless sprayers can be used for a wide range of coatings for both interior and exterior jobs and can easily be transported around job sites.

Today, there are four main types of spray delivery methods…

Air Spray

The first spray delivery method is Air Spray. These systems use highly pressurised air, created by a compressor, to atomise the fluid being sprayed and deliver it onto the work surface.

High-Volume, Low-Pressure (HVLP)

FinishPro HVLP

Another fluid spray method is High-Volume, Low-Pressure – or HVLP. These systems also utilise compressed air, but in a different way than standard air spray systems.

With an HVLP sprayer, a turbine delivers a large volume of air at a much lower pressure to atomise and spray the fluid. In fact, the unit must be 0.7 bar (10 PSI) or less at the air cap to qualify as HVLP.

These systems are designed for smaller fine finish jobs because they provide the least amount of over-spray and unmatched precision for the highest quality professional finish.

Airless Spray

The third spray delivery method is Airless Spray. This method differs from the previous two as these sprayers need neither a compressor or a turbine. 

Airless spraying is the fastest and most versatile way to achieve professional painting results and spray the widest variety of materials, un-thinned. In fact, using an airless sprayer is up to 10 times faster than using a brush and at least four times as fast as a roller!

Airless spraying achieves this speed by atomising, or breaking up fluid into small droplets, without the use of compressed air. Instead, fluid is pumped under high pressure through a spray tip. The fluid emerges from the tip as a high-speed solid stream – but when that stream hits the air, it becomes disrupted – and the fluid separates into very small droplets that form the spray pattern.

If you’ve ever placed your finger over the end of a running garden hose, you created a very simple form of airless spray.

Airless paint sprayer

Air-Assisted Airless

Graco air-assisted airless sprayer

Finally, Air-Assisted Airless is the fourth delivery method. This system combines airless and air spray methods to deliver the finish quality of an HVLP sprayer, with the speed and efficiency of an airless sprayer. This is achieved by adding compressed air to an airless spray fan pattern.

With air-assisted airless spraying, material is delivered to the gun at 20-40% lower pressure than traditional airless spraying (34-103 bar (500 – 1500 psi) vs. 103-206 bar (1500 – 3000 psi)) and is partially atomised through a small tip. Full atomisation is achieved by adding a small amount of air (0.34-2.4 bar (5 – 35 psi)) to the edges of the spray fan – resulting in a softer pattern, more control, higher transfer efficiency,and less over-spray.

So, what is airless spraying? Simply, it’s the fastest and most versatile way to achieve professional painting results.

Graco Hydra Spray