As a remodeling contractor, I go through 100 to 150 gallons of
paint per year. My early efforts at painting with consistency
and efficiency were frustrating, and my first attempts to use a
paint sprayer only made things worse. Dealing with thick clouds
of overspray, runs, clogged sprayers, and impossible cleaning
chores nearly convinced me that spraying was better left to the
It wasn't until I actually watched a real pro carefully spray
around windows with almost no overspray that I realized how
much more there was to choosing and using the equipment than
I'd thought, and how powerful a tool this could be for a
Contractors who do multiple medium-size renovations or their
own painting — or who want to add painting to their
arsenal — should look into purchasing and learning how to
use an airless sprayer.
The Benefits of Spraying
Spraying is two to four times faster than brushing or rolling,
and multiple coats can be applied in the same day with the
right materials. Once you've gained experience, getting into
corners, cutting in around borders, coating complex surfaces,
and providing consistent, high-quality results become second
Properly applied spray finishes are higher in quality than roll
or brush finishes, without the lap and stroke marks common to
other application methods. Spraying doesn't have to be limited
to coating wide expanses like house exteriors or blank walls,
either; all the trim for a house can be laid out and sprayed at
once, or all the balusters on a porch or deck can be finished
in far less time than by brush. Overall, spraying can be a
profitable addition to your standard painting offerings.
Selecting a Paint Sprayer
Walk into any professional paint store or home-improvement
warehouse and you will be faced with a bewildering array of
sprayers. Many promise the ability to spray "thick liquids" or
show smiling homeowners flawlessly one-coating their homes.
"Thick," of course, is in the eye of beholder. What we're
really after is the ability to apply the correct amount of the
Airless sprayers operate with a constant amount of paint in the
hose and gun, held under high pressure. When you pull the
trigger, the pump pushes against the paint, atomizing it and
forcing it through the tip. Application rate in gallons per
minute (gpm) is one of the most important criteria when
selecting a sprayer, because it directly influences the tip
size and the materials you can spray. Although stores or
manufacturers might tout pressure or unit hp, what matters is
being able to properly atomize materials without thinning or
having to use maximum pressure. Proper atomization helps reduce
problems like overspray.
The easiest way to determine how large a unit you need is by
finding the heaviest coating you might apply — generally
a professional latex or even a masonry waterproofing paint
— and looking at the instructions on the back of the
paint or stain container. Manufacturers typically provide a tip
range for spraying the material (see Figure 1); for instance,
Sherwin-Williams A-100 calls for a .017-inch-diameter
Figure 1. Choosing a powerful enough
airless sprayer is a matter of matching the viscosity of the
heaviest paint you need to spray with the proper-size spray
tip. Paint-can labels (top) display the recommended tip size;
sprayer-manufacturer literature, like this spec sheet from
Sherwin-Williams (middle), tells you how large a sprayer is
required, in gpm, to support that tip. Based on the total
amount of paint he sprays in the course of his work, the author
chose one of the smaller pro-duty units.
Once you know the tip size, you can determine what flow rate
the sprayer will need in order to successfully atomize the
paint; in this case, you'd need a unit with an effective flow
rate of .31 gpm. Where did I get that number? From the back of
the tip package. So you'd want a unit that supports that size
tip at a minimum.
I also recommend that you buy a unit that will support a tip at
least one or two sizes larger than what's required to move the
type of paint you normally use. The unit will have a larger
pump, which means that you can more effectively fine-tune the
rate of flow.
Pump types. There are two types of
pumps used for airless sprayers: piston pumps and diaphragm
pumps. In general, lower-end models use a diaphragm pump, in
which an impeller revolves, pushing the paint along. Piston
pumps are found on higher-end models, like the pro-duty
sprayers from Graco (www.graco.com), SprayTech
(www.spraytecsys.com), and Titan
(www.titantool.com). These brands typically
have better, longer-lasting motors, require less service, and
outperform less-expensive brands.
Price and Selection
I recommend that anyone considering buying an airless spray
unit visit a professional paint store that supports a large
selection. In addition to having more to choose from, you'll
get professional advice. Models sold by professional suppliers
tend to cost more than those bought from a catalog or Web site,
but a good paint store should be able to help you select the
right equipment for your intended applications, as well as
provide service work when needed. And, as with any professional
tool, buying job-specific equipment will generally deliver more
consistent results with less aggravation.
Also, don't forget that there is a host of accessories for
airless units: extensions, rollers, special tips, mobility
carts, and additional-length hoses. Before buying, check with
the sales department to ensure your unit will support a longer
hose; more length means more paint to keep under pressure,
placing greater demand on the motor. Once you learn the basics
of your system, items can be added to make the job easier, such
as extensions and roller handles.
Selecting the Right Tip
The first step before actually painting is selecting the proper
tip size; the tip determines the overall quality of the paint
job. It controls how the paint is applied, providing optimal
professional results. Proper tip selection is what changes an
airless sprayer from a crude instrument into a precision tool;
the trick is to carefully match the tip size to the
application, whether it's trim or wide-open areas.
Tip sizes are always given as a reflection of the orifice in
fractional inches: .015, .017, and .019 are examples of common
tip orifices (Figure 2). To select a size, begin by considering
the type of material you're using. In general, thinner
materials need smaller tips, and heavier materials need larger
4 x 2 = 8-inch fan width
17 = .017-inch orifice diameter
Spray tips come in a
range of sizes and are chosen according to the solids content
of the paint as well as the fan size needed for the
application. Most American manufacturers use a three-digit
sizing convention. The first digit equals half the width of the
fan; the next two digits represent the orifice diameter in
thousandths of an inch.
Next, select the fan size, or the area of spray coverage when
holding the gun 12 inches from the surface being painted. Most
American equipment manufacturers, such as Graco, employ a
numbering system in which the first digit indicates one-half
the fan width, and the second and third digits indicate orifice
size. Thus, a Graco 517 tip would have a fan width of 10 inches
and a .017-inch orifice size.
Choosing a tip doesn't have to be complicated. Spraying huge,
blank wall expanses can call for wide spray patterns and quick
work. More delicate tasks, like painting around windows or
other contrasting objects, might require a smaller fan width
for better control. Select the tip that best meets the needs of
both the job overall and the objects you're painting.
A final note about tips: Although manufacturers offer
long-lasting tips, even they eventually wear out. Excess flow
rate, smaller fan sizes, and runs can result. When the fan
width suddenly decreases by more than 20 to 25 percent of its
original size, it's time for a replacement.
Always observe safety precautions when using airless sprayers.
Because of the high pressure — up to 4,000 psi —
involved in spraying, an air-entrainment injury, in which paint
is injected underneath the skin, requires immediate medical
attention even if the injury appears to be small. Sprayers can
inject paint deep into the tissues of the body with little
outward sign, causing necrosis (tissue death). Without
immediate medical help, this condition could eventually lead to
The second medical concern — which also cannot be
understated — is the possible long-term health
consequences associated with breathing the vapors of the
materials you're using. While the hazards of breathing fumes
from oil- or alkyd-based products are well-known, most people
don't realize that long-term exposure to water-based finishes
can also cause lung problems.
At a minimum, appropriate paint respirators and safety glasses
must be worn, and great caution should be exercised when using
an airless system. Just as with a nail gun, one slip could
cause permanent damage.
Always remove pressure from the system before moving it around,
cleaning the tip, or making other adjustments.
On home-improvement shows, the act of spraying tends to be
oversimplified. Spraying is both a technique and an art; you
must take into account the different surfaces, paint types, and
items to be sprayed around.
In almost all cases, the gun should be held straight up and
down, parallel to and 12 inches away from the surface. Move
your whole body along the surface, not just your wrist and gun;
they should stay in the same fixed attitude while spraying
To apply an even coat, hold the gun
parallel to the surface, whether moving horizontally (top) or
vertically (middle). When reaching high, make sure to maintain
this position rather than angling the gun (bottom).
When spraying, activate the trigger before moving over the
receiving surface, then continue moving beyond it before
releasing the trigger. Application speed must be consistent;
moving too fast or pulling the gun away leaves too little paint
on the surface; moving too slow or angling the attack so that
the gun is not parallel to the wall can lead to overapplication
and drips. This is the art of spraying; getting the right
results is a matter of knowledgeably gauging various factors
— speed, material, surface.
We typically spray big areas first, then move to the smaller
parts, using different tips to cut into corners and around
windows and protrusions (Figure 4). We always make generous use
of paint shields and drop cloths (Figure 5).
Maintain a vertical wet edge when
you're spraying a second coat; it's a good way to keep track of
what's already been sprayed.
Figure 5.Taking the time to
apply masking tape makes for fast cut-in (top). This hand-held
masking tool (bottom) allows the author to cut in against a
soffit of contrasting color with great accuracy.
Overspray. I hear a lot of complaints
about overspray. The problem could be caused by a number of
different factors: The material is too thin or has been thinned
for spraying with a smaller sprayer; the wrong tip or gun is
being used; the pressure is set too high.
If you're getting a lot of overspray, go to a larger tip and
increase your application speed while decreasing the sprayer's
pressure. If the tip isn't specifically supported by the
sprayer used, it's probably too small to obtain good results
with the material you're using.
Most common spraying problems can be remedied by making
adjustments in technique or equipment. Tailing, for instance
— small, parallel paint marks above and below the main
spray pattern — occurs when the gun is held too far from
the surface, the pressure is too high, or the tip is
Spattering results when there's insufficient pressure or a
problem with the tip — it's either worn or too big for
the unit. Orange-peeling happens when material is sprayed on a
too-hot surface like aluminum siding.
To Back-Roll or Not?
Among professionals, this is the big question — and
there's no uniform agreement on the answer. Both methods have
Many believe back-rolling is necessary to force the paint
product into the surface. But at delivery pressures of 2,000
psi or greater, the material should adequately embed in the
Others argue that rolling is necessary to achieve a smooth,
consistent paint application. But the beauty of a sprayer is
its ability to provide fast, consistent quality — a
result that comes from practice, not from back-rolling
everything. In my experience, once you get the right sprayer
and know how to use it, back-rolling is not necessary.
Cleaning and Maintenance
Cleaning seems to be a major problem, especially for users of
older or poorly designed units, which can be a pain to take
apart and clean correctly. Make sure to ask about cleaning and
maintenance before purchasing an airless spraying outfit.
Nowadays, some units can be connected directly to a garden hose
for fast cleaning. With others, you have to disassemble several
components, remove the paint from the system, and then run an
appropriate cleaner through the system.
To clean my unit, I generally start by removing the paint
pick-up tube from the paint and cleaning it; I immerse it in a
5-gallon bucket of clean, warm water. I then remove the tip
holder and pump the remaining paint in the hose back into the
paint container. As soon as the paint flow lessens, I switch to
rinsing. Generally, 1 or 2 gallons of clean water pumped
through the hose and gun provides complete cleaning.
While still pumping, I take apart and clean the gun, handle,
tip, and filters. Last of all, I oil the unit, particularly the
piston, in preparation for the next time I use it. Total
cleanup time? Usually 10 minutes or less.
After choosing a good solid airless spraying unit and learning
how to use it, contractors who handle their own painting can
expect to improve both their time line and their bottom
Jason Seltin is a remodeling contractor in
Saint Johns, Mich.