Choosing The Correct Spray Painting System
Airless Spray Painting Systems
In our past few articles, we’ve given you breakdowns of traditional air spray painting systems, including conventional pressure-fed and high-volume, low-pressure (HVLP) — and now, it’s time to dive into the third type of spray painting system we mentioned in Part 1 of this series.
Here’s what you need to know about airless sprayers.
How do airless spray guns work?
As you might expect, airless spray guns dispense with the air source associated with pressure-fed and HVLP systems. Instead, they’re powered by a motor (electric, petrol, hydraulic, or pneumatic) and use either a diaphragm or piston pump to send paint through a hose and out the gun tip.
Generally, the pressure in airless systems sits around 2000psi — but it varies, with some units spraying at a massive 3650psi and others as low as 900psi (the latter thanks to new technology called High-Efficiency Airless (HEA) or Fine-Finish Low Pressure (FFLP)).
The major difference between airless sprayers is the litre per minute rate at which they can pump the paint. A small tradesman unit will be around 1.8-2.0 litres per minute; however, if you need to spray intumescent coatings, a larger unit will provide the necessary litreage. Airless sprayers can get up to more than 15 litres per minute.
Airless spray gun tips are interchangeable, enabling you to use appropriate sizes for different liquids and different jobs. Working with thin liquids? Choose a smaller tip. Need to spray thicker, more viscous materials? Opt for a larger tip to make it easier for the gun to smoothly pump the liquid through the hose and onto your surface.
(A quick note: we’ve written a comprehensive guide on airless spray tips, covering what the numbers on them mean and how to choose the right one for whatever job you’re undertaking. Check it out here.)
Regardless of the tip you choose, airless systems invariably offer quick application rates and smooth finishes. Thanks to their higher litre-per-minute configuration, they also allow you to complete large jobs in shorter periods of time.
The pros and cons of airless spray guns
Airless spray guns are by far your best option if you’ve got a job that needs to get done quickly.
They’re conveniently portable, and you can use them for a wide variety of different jobs, both interior and exterior.
Airless sprayers come in a wide variety of sizes, from small handheld units through to large industrial units.
The biggest disadvantage of an airless sprayer is that it inevitably comes with a bit of wastage. Because the paint is delivered under pressure, a percentage of the product will invariably bounce off your surface and create overspray — which, in turn, means you have to cover absolutely everything you don’t want to get paint on.
(If you’re painting outside, for example, even a little breeze can pick up paint droplets and deposit them onto surfaces like your car or the sides of your house.)
What can you use airless spray guns for?
Because they’re ultra-efficient, airless sprayers are ideal for large jobs such as painting roofs, walls, or fences.
They’re also a prime option for any job where a smooth finish is key, such as on doors, cabinets, and all types of woodwork.
Airless sprayers are used extensively in industrial applications to apply specialist coatings such as fire retardants, plasters, renders, and anti-corrosive primers. They're also used as job-specific machines, such as line markers.
Not sure what airless sprayer is right for your job? Send me a message with a bit of information about what you’re looking to use it for, and I’ll help you find the perfect spray painting tool.