Airless Paint Spraying Guide

What is Airless Paint Spraying?

Man Airless paint Spraying


Airless paint spraying is a method of painting in which a paint sprayer with pressurized fluid is used instead of compression-powered air painting. The high-pressure fluid is used to atomize the paint and expel it through the nozzle as fine high-speed droplets.


Any beginner to spray painting may struggle to distinguish between air spray painting and airless spray painting. The difference between the two lies in their working concepts; while an air paint sprayer uses an inbuilt compressor to produce the air that’s responsible for the pressure, the airless paint sprayer uses other fluids instead of air as a method to produce aerosols. Basically, the airless sprayer does not need a compressor to paint.

Rather, they generate paint aerosols by pumping the paint at high pressure. These two differences affect their applications discussed later in this post.

If you are looking for a spray painting appliance with speed efficiency and high transfer rate then an airless paint sprayer would be a great option for you. That’s because airless paint sprayers are mainly availed for medium to high viscosity fluids capable of giving a low finish quality.

After defining the airless paint sprayer, let’s glance at the major differences between airless and air paint spraying:

Workhorse: Airless sprayers are designed to work on large painting jobs. They outperform air paint prayers which are designed to handle smaller painting jobs. So if you want to add a smooth finish on your doors, fences, and several cabinets, the best prayer for the task would be airless paint sprayers.

Performance: Unfortunately, air paint sprayers outshines airless paint spraying in changing the quality of the pray. That’s because air paint sprayers employ the HVLP (high-volume low-pressure) technology which ensures that the pressurized material leaves the orifice (which is smaller than the HVLP nozzle) at high pressure.

Transfer rate: Air sprayers also outshine airless prayers by achieving a transfer rate of about 90 percent of the materials. The airless sprayer has about a 50 percent transfer rate.

How Does Airless Paint Spraying Work?


Airless paint sprayers rely on the fact that it takes surface tension and viscosity to hold liquids together. Atomization of the liquid leads to the formation of a mist of fine droplets rather than continuous liquid flow.

In airless sprayers, the high pressure that’s generated produces tremendous energy which forces the paint out of the nozzle. Although this energy plays a role in the atomization process, actual atomization takes place on the surface being sprayed, not inside the sprayer.

Since an airless sprayer is devoid of a compressor, a motorized pump is used instead to force the paint out of the reservoir. The nozzle is thin enough to enough build high pressure as the tip as the paint exits it.

This built-up high pressure at the end of the tube causes the atomization of the paint, hence resulting in the paint being pulled apart into fine mists. This forms a smooth finish that consists of a minimal amount of paint.


The Components of an Airless Machine



The anatomy of an airless sprayer is an elaborate one. Let’s have a deeper look at each part:

Pump/Fluid Section

This is the heart of the airless paint sprayer. The pump’s function is to pressurize the paint. To withstand rough handling and the high pressure inside, the pump is usually made from heavy-duty steel. Some pumps may be made to be extra enduring by the addition of harder materials like Chromex Rod (as it’s the case with Graco’s Endurance Pumps).

Motor

The motor is the second most critical part of an airless paint sprayer. It is the component that does all the pumping. Most of the airless sprayers on the market use electric motors while a fistful of other opts for gas engines instead. Most manufacturers put the device’s warranty on the motor, with some reliable manufacturers promising a lifetime warranty on their motors.

Drive train

A drive train serves to link the motor and the pump. Very much like the axels and transmission in a car, the drive train delivers the power where it is needed most.

Hose

For the airless paint sprayer to be functional, its pressurized paint needs to be transferred from the reservoir tank to the sparing tip and gun. The function of a hose is to transfer the paint from the rank to the nozzle. The hose is specially designed to hold and deliver pressurized paint without bursting.

Gun

The airless paint sprayer would be useless if it can’t temporarily hold the paint somewhere until it’s needed. The gun does exactly that; it allows the user to hold the paint inside and only permit it out when required. The gun also makes it possible to safely turn the flow on and off.

Tip: The tip of the gun doesn’t just control the amount of paint leaving the sprayer, it also controls the size of the spray-fan. For that reason, it would be great if you bought more than one size of the tips in your kit.

Pressure control

You can’t control the pressure in with the hose, gun, or tip. Hence you need a special component that takes care of this job, that component is called pressure control. An airless paint sprayer comes with either of the two types of pressure controls: mechanical and electronic. As you can tell, mechanical pressure controls are activated and deactivated mechanically while electronic controls are controlled using electronic circuits.

Chassis

The chassis of the airless paint sprayer works very much like any other sort of chassis you would find in any device; its main function is to hold all the components of the system together. There are 3 design configurations: Hi-Boy (upright cart chassis), stand (or “skid” chassis), and Lo-Boy (often referred to as “low-profile cart”).

Prime/Spray Valve

This switch serves to set your airless paint sprayer to one of its two modes: pray mode or prime mode.

Cylinder

The cylinder is the section that houses the balls, packings, and rod. Manifold filter

This is a filter assembly that serves to trap all the debris that could reach in the sprayer and clog the system or affect the quality of the paint.

Inlet

Inlet is part of the piston pump. It is one of the two back checks at the bottom of the cylinder. The inlet ball regulates the amount of fluid entering the fluid section. During upstroke (when the user pulls up the rod) the inlet permits the paint to move upward from an interconnected inlet tube.

Outlet

The outlet valve and ball assembly work similarly to the inlet assembly except that it is located at the topmost end of the cylinder. The outlet permits the paint to flow all over the fluid section. During downstroke, the valves in the outlet permit the paint to flow out of the fluid section into the hose and then into the gun.

Packings

Piston packings form a seal within the cylinder as the central rod move down and up (very much like a doctor’s syringe). This part also permits the paint to flow freely all over the pump.


The Benefits of Airless Spraying



Speed and Efficiency

Painters used to paint their items by hand or use of rollers will be surprised by the ease of use and adaptability of an airless paint sprayer. The conventional brush is advantageous if you consider their ability to fill the surface in greater detail but it isn’t particularly great if you have several surfaces to paint – it can be time-consuming and exhausting at the same time. The paint roller, on another hand, has an undesirable tendency to leave ugly streaks all over your paintwork. The airless sprayer offers a better option if you want a speedy and more efficient alternative.

Uniform application

Painting rough or not-so-ideal walls can be a tough job. Such surfaces as uneven walls, popcorn-effect ceilings, and textured walls require a special painting method better than rollers and painting by hand. An airless paint sprayer comes handy for such tasks. It produces an atomized mist of paint that sticks to the smallest cervices on any textured surface.

No compression

We all know that airless paint sprayers aren’t the only painting devices on the market. Other options like air paint sprayers (note the difference of the two at the start of this post) outshine the airless paint sprayer in some areas. However, one of the biggest benefits of using the airless paint sprayer is that you won’t need to rely on compression methods to expel the paint via the nozzle.

Airless paint sprayers use hose method and pressurized fluid instead of the compression techniques to expel the paint outside. Avoiding the compression technique means you won’t have to deal with overspray problems.

Portable

Who wants to move around with those bulky and large paint machines? These machines require a person to push them from place to place.

All you need to move around with an airless paint sprayer is a simple cart that can reach even the most remote rooms of the house. And if you dismantle the parts such as removing the hose, you can easily carry the components in your hand anywhere.

Superior and quality finish at very low costs

The atomized mist of paint produced by airless paint sprayers has two advantages. Firstly, the paint sticks on the surface immediately because it is charged (through the high pressure at which it leaves the gun). Secondly, the paint leaves the gun as a mist instead of torrents. This helps you to avoid wasting and overusing your paint. In the long run, users can realize that an airless paint sprayer is a money saver.

The thickness of the material

With an airless paint sprayer, the user has greater control over the thickness of the layer of the paint applied on the surface. You can replace the tip with another tip if you want to achieve a specific thickness. For instance, if you want thinners (low thickness) materials such as coating or stain, you’ll need to add a small-holed spray tip. Heavier materials such as latex will require a big-holed spray tip.

How Airless Spraying Compares to other Paint Application Methods



Price


When it comes to price, airless paint sprayers emerge costly compared to their air counterparts. The price of an air paint sprayer ranges between £20 and £100. Meanwhile, an airless sprayer sells at around £200 and can sometimes be as up as £2000. This is partly because of the quality work done and time effectiveness delivered by airless paint sprayers.


Application Use



When it comes to application use, airless paint sprayers compliment air sprayers instead of replacing them – the two tend to fulfill each other’s work. For example, both of them are great choices if you want to cut on overspray and save your paint.

The difference only comes into the mix if time and scale of work are factors to consider, of which the airless paint sprayer turns out to be a better option if time is short and the size of the work is large.

Material Viscidity



Not all sprayers can handle different materials in the same way. It is important to understand what each sprayer is capable of handling before putting any paint.

Airless paint sprayers use high pressure to create paint aerosols, hence you don’t need to thin your paint first before painting. These sprayers are capable of handling most viscosities quite easily.

Air paint sprayers, on another hand, don’t work well with thick paints. A thinning procedure needs to be done on thick paints before using them. These sprayers also struggle with enamel latex paints because they don’t react well to the high pressure.

So if you are dealing with thick paints or you know you will be using different types of paints, you’ll most likely consider opting for the airless paint sprayers instead.

Conclusion

The airless paint spray is one of the best painting options out there. Although it has considerable advantages over the air paint spray, the two complement each other most of the time. But it is far better than rollers or painting by brush.


Related Reading

HVLP Vs Airless

Beginners Guide to Spraying

Guide to HVLP