Spraying VS Brushing or Rolling
Maximizing Paint Usage
Whether you’re adding a fresh coat of paint or completing a color change, the amount of material and time needed to complete either job can vary. So, what application method uses more paint – brushing/rolling or spraying?
In addition to finishing the job faster, an airless paint sprayer will be more efficient for the time and amount of paint needed to complete the job.
Some of the key variables to better understand material usage include:
- Application Methods & Challenges
- Paint Thickness (mil build) Consistency
- Material Requirements for Tools
- Material Waste
Painting Methods & Challenges
Brushing & Rolling
When painting with a brush and roller, paintbrushes use bristles or foam and roller covers use a nap or foam roller to hold and distribute the paint across the surface. A standard brush will be around 2” but are available in larger and smaller sizes. For brushing, a paint cup is often used to hold the paint in smaller amounts.
Roller covers are typically 9” long and use a ¼” nap for smooth surfaces and ¾” nap or thicker for rough surfaces and texture finishes. Roller pans or roller screens inserted inside a 5-gallon bucket are options to consider for roller applications.
While brushes and rollers come in different sizes, properly managing the paint throughout the job presents challenges that impact efficiency. Regardless of the care and time involved with preparing the area to paint, excess paint will almost always find its way onto a surface via spills and drips. In addition to adding more time to the job, these unexpected issues can present a serious challenge to remove properly without impacting the existing finish – especially if not noticed early on.
Given that preparation and cleanup make up the majority of time on almost any painting job, airless spraying is over 7X faster than brushing and rolling once the actual painting starts.
With airless spraying, the fast moving high-pressure liquid stream provides the energy necessary to overcome the fluid’s viscosity (resistance to flow) and surface tension (a force that bonds the surface of a liquid together) to form a fine spray. In the depiction of spray from a gun, high pressure forces fluid through a small nozzle (spray tip).
The fluid emerges as a solid stream (sheet) at a high speed. When the solid stream hits the air, it becomes disrupted. This disruption breaks the fluid into fragments initially, then ultimately very small droplets that form the spray pattern. The tip size and pressure is what determines the material flow rate. The tip also creates the size and fan pattern width.
Since airless spraying can produce overspray (depending on tip size and pressure used), thorough preparation is a must when using an airless sprayer. The overspray can be magnified if the application is outside when there is a small amount of wind as the fine spray can be blown onto other surfaces. Reducing pressure or selecting a different spray tip can help manage potential overspray issues.
Paint Thickness Consistency
Paint thickness (mil build) on the surface will vary depending on the application speed and the amount of paint in the brush or roller. This inconsistency can make it more challenging to achieve a uniform color and mil build consistency throughout the entire surface.
The atomized paint droplets created by an airless sprayer produces an even spray fan that provides an even distribution of the paint. This consistent distribution of paint on the surface can reduce the amount of paint needed to achieve a uniform finish.
While both brushing and rolling are often time consuming and messy, they also produce a decent amount of dried, unusable paint on the edges of the cup or pan after the remaining paint is transferred back into the bucket. While this may not seem like much material, this unused paint can add up over the course of a large job.
With an airless sprayer, there is no premature curing of the paint since the paint is sealed in the sprayer system. Any unused material is easily removed from the system and can be used for touchups or other projects.
To empty unused paint from an airless sprayer, simply insert the system inlet into a bucket of water (or mineral spirits if using oil-based paint) and spray the paint back into the original bucket until water starts exiting the spray gun. To fully clean the airless sprayer, continue to run water (or mineral spirits if using oil-based paint) through the system until the spray is clear.
Advantages of Airless Sprayers
Airless sprayers provide an easy and economical way to apply coatings. Professional contractors prefer to use airless sprayers for several reasons, including:
Airless spraying is up to 10 times faster than brushing or rolling so more jobs can be completed in less time, using less labor.
Airless sprayers produce an even coat of paint on all types of surfaces, leaving a consistent and high quality finish.
Airless sprayers can be used for a wide range of coating materials, including interior and exterior jobs, and can easily be transported from jobsite to jobsite.
Low Pressure Spraying
New airless spraying technologies can also help maximize material efficiencies. For example, new low pressure spray tips are becoming more popular due to the multiple benefits they provide. While low pressure tips have typically been used on fine finish jobs like millwork and cabinetry, there are now low pressure tips available for a variety of projects and materials — including high production and large surface area jobs.
One of the main benefits to low pressure spraying is a significant reduction in overspray to use less paint and create less mess due to more material hitting the surface. Less mess also results in reduced prep and cleanup time so you finish jobs faster.
Low pressure spraying also provides a softer spray fan to make pattern overlap easier for a better quality finish. These low pressure tips also help prolong the life of the airless sprayer as it doesn’t need to generate as much pressure to produce the same spray fan.
Ultimately, airless spraying is the most efficient painting method in terms of time need to complete the job and overall material efficiency.
Intro to Airless Paint Spraying
By applying paint in an even, consistent manner, airless spraying allows you to achieve professional results faster and easier than using a brush or roller.
Components of an Airless Paint Sprayer
Before spraying, understand how the primary components of a Graco airless paint sprayer work together to create a perfect finish with unmatched performance.
Airless Texture vs Airless Paint Sprayers
Explore the differences and similarities between Airless Texture Sprayers and Airless Paint Sprayers.