The Best Paint Sprayer For Simple Coverage

Paint sprayers come in many types, each of which is created to meet a particular need. You can’t effectively paint a building using automotive spray equipment (trust me, I know; I learned that the hard way as a teen). Nor can you paint a car with an airless paint sprayer and latex paint. Just like there are different types of paint, created for different applications, there are also different types of paint sprayers, created for use in applying those different paints.

Paint Sprayer Types

Paint sprayers basically fall into three different categories, depending upon how much air they use to spray the paint.

Air Paint Sprayers

Air paint sprayers are the most traditional category. They use compressed air to atomize the paint and propel it to the surface being painted. These paint sprayers also allow for changing the height and width of the spray "fan",  allowing the painter to set the sprayer for the most efficient use of the paint.

Generally speaking, air paint sprayers are used for automotive paint applications. However, they can literally be used to paint just about anything. The tips are interchangeable so a tip can be chosen that’sthe right size for the viscosity or thickness  of the paint being used.

There are two different ways that air paint sprayers can receive the paint to be sprayed; via a gravity feed cup or a pressurized paint pot. The cup is great for smaller jobs, such as touching up a car after replacing a fender. The pressure pot is used when larger amounts of paint are needed, such as painting an entire vehicle. Typical pressure pots hold one quart of paint, although there are also some that hold two gallons if you need to paint something like a 747 or something else large like that.

Airless Paint Sprayers

While theoretically it’s possible to use an air paint sprayer for architectural painting, it's not really practical. Painting homes and commercial structures uses so much paint, that you would end up refilling the paint pot on an air paint sprayer constantly. Therefore, airless paint sprayers are used.

An air paint sprayer creates a stream of air that draws the paint along via the venturi effect. This works well with low viscosity paints, such as those used for automotive painting. However, it doesn't work all that well with high the viscosity, high solids paints used for homes and businesses, especially latex paints (which are higher viscosity than oil-based paints). Instead of this, an airless paint spryer pumps the actual paint to the gun at high pressure where the pressure causes the paint itself to atomize through the nozzle of the gun.

To accommodate this, the design of the spray gun must be different. It is not receiving both paint and air, but only paint; this makes for a simpler gun design. However, the higher viscosity paint has more of a possibility of clogging the nozzle, so the better airless paint sprayers have reversible nozzles, so that you can blow out a clog and keep on painting.

HVLP Paint Sprayers

HVLP, short for "high-volume, low-pressure" is the new kid on the block. It has been developed to deal with the problem of overspray, caused by paint bouncing back off of the surface being painted. Since only low air pressure is used, there is less bounce back, hence less overspray.

The secret is using a higher volume of air to carry the paint. This allows the lower air pressure, while still causing the paint to be carried to whatever is being painted. While there is no such thing as a HVLP for normal latex paint, HVLP is used with oil-based paint for painting door and door frames, as well as for applying stain and varnish, in architectural applications. HVLP is also currently used extensively in automotive manufacturing.

The one problem with HVLP is it tends to provide more orange peel than high pressure air spray guns. The newer spray guns have gone a long way towards eliminating this, with improved airflow and improved nozzle technology.

Orange Peel

When we talk about finish quality in painting, the major factor being considered is what’s known as “orange peel”. If you think of how the surface of an orange looks, that pretty well demonstrates what orange peel is. For automotive, furniture and other applications that are viewed up close, orange peel is essentially considered unacceptable. Of course, runs and drips can exist with any type of paint application and those are unacceptable in all circumstances.

Technically, orange peel refers to the roughness of a surface finish provided by the paint sprayer. All spray guns create some orange peel, due to the way that the paint droplets hit the surface being painted. How much orange peel is created is caused by a combination of paint gun design, paint viscosity and how fast the paint dries. Slow drying paints have more of a chance of "flowing out," eliminating the orange peel texture.

Orange peel is the worst when only a light coating of paint is applied. The more paint that’s applied, the more of a chance for it to flow out. However, there’s a point where enough paint can run or sag before it can dry. Ideally, you want to stop just short of this point when applying the paint.

For extremely fine automotive finishes, the paint is sanded and buffed once it’s dried  in order to cut the tops off of the orange peel and provide a glass-smooth finish. This is then often covered with several coats of clear coating  which is treated in the same way, sanding it and polishing it to provide the final finish.

Airless paint sprayers tend to cause a lot of orange peel, but it is not normally noticed, as architectural applications are normally done over textured surfaces. The one place where they are most likely to be noticed is in the case of interior walls which are almost always textured.