Introduction
Learn how to use an airless paint sprayer to paint faster with perfectly smooth results. We show you how the machine works, good painting techniques and how to avoid mistakes.If you want to speed up a big job, like painting the exterior of your house, or one that requires glass-smooth finish on woodwork or doors, that’s when professional painters reach for an airless paint sprayer.
What Is An Airless Paint Sprayer and How Does It Work?
As the name implies, airless sprayer doesn’t need compressed air to pressurize paint and push it through the tip of a spray gun like a standard paint sprayer or an HVLP paint sprayer does. Instead, it uses an electric or pneumatic pump, in some gases a gas-powered engine, to accomplish that.
It works by pumping paint at a very high pressure, up to 3,000 psi, through a hose and out a tiny hole in the spray gun tip. The tip is designed to break up the paint evenly into a fan-shaped spray pattern of tiny droplets. Using different tips, you can spray thin liquids like stain, lacquer and varnish or thicker liquids like latex house paint. With a little practice, you can use an airless sprayer to apply a perfectly smooth finish on doors, cabinets and woodwork.
And since an airless sprayer pumps paint directly from a can or 5-gallon bucket, you can apply a lot of material in a short time. This makes an airless sprayer particularly well suited for large paint jobs, like priming bare drywall in a new house or painting a 300-ft.-long privacy fence.
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Drawbacks of Using an Airless Paint Sprayer
But before you get too excited about the benefits of spray painting, there are a few drawbacks to consider. First, the fine particles of paint don’t all stick to the surface. A large percentage of the paint ends up in the air, where it can drift and settle onto everything in sight. This means you’ll be wasting 20 to 40 percent of the finish, depending on the application. You’ll also have to take extra time to mask off and cover up everything you want to keep paint free. Outdoor painting is especially risky. Overspray can end up on your shrubs or roof, or drift with the wind onto your neighbor’s car.
The other downside is the extra time it takes to flush the paint from the pump and hose and clean the sprayer. If you’re using your own sprayer or an electric paint sprayer, rather than a rental unit, you’ll also have to clean the filters and install special storage fluid. And if you’re spraying oil-based products, you’ll have to store or recycle a gallon or two of used solvents left over from the cleaning process. But despite these disadvantages, an airless can save you a lot of time on big paint jobs and allow you to get a finish that’s nearly impossible to get with a brush.
Which Tip to Use for Painting with An Airless Sprayer
Spray tips slide into a hole in the front of the airless paint sprayer gun. They’re labeled with a three-digit number like 309 or 517 (these may be the last three digits of a longer model number). Doubling the first digit tells you the spray fan width with the gun held 12 in. from the surface. A 415 tip, for example, would have an 8-in.-wide fan, while a 515 would have a 10-in. fan pattern.
The next two digits indicate the size of the hole in thousandths of an inch. Choose a smaller diameter hole (.009 to .013) for thin liquids like stain or varnish and a larger hole (.015 or .017) for thicker liquids like latex paint.
A 411 tip would work well for spraying varnish on woodwork, while a 517 is a good size for spraying large surfaces with latex paint.
Airless Sprayer Safety
Read and follow the painting safety precautions included in your sprayer manual. If you rent a sprayer, ask for a list of precautions.
Here are the most important ones:
- Keep the trigger locked and follow the pressure relief procedure when you stop spraying, before cleaning, and before servicing the sprayer or installing tips. Never put your hand in front of the sprayer tip unless the unit is off and depressurized. The high-pressure spray can inject paint under your skin, causing a serious poisoning hazard. If you do puncture your skin with the spray, get to a doctor immediately.
- Wear safety glasses and an approved respirator when you’re spraying.
- Work in a well-ventilated area.
Caution: When you’re spraying flammable oil-based products, follow all grounding precautions to prevent sparks. Read your manual or ask the rental store for instructions on grounding the gun and metal pail.
Before you start spraying
Whether you rent or buy an airless sprayer, there are a few key setup points. All sprayers have a screen at the intake point. Make sure it’s clean. Most sprayers also have a removable filter near the pump and another one in the handle of the airless spray gun. Check both to make sure they’re clean, and plan to strain your paint through a mesh filter bag to remove lumps so they won’t clog the filters.
