EQUIPMENT : House Painting? It Pays to Spray--and to Practice

Many professional house painters now use spray equipment more often than brushes and rollers to apply paint. Homeowners can, too, with sprayers specially designed and priced for amateurs.

Spray-painting is fast and produces an even coating without leaving brush marks. A few minutes of spraying often is enough to cover difficult surfaces such as shutters and fences that might take hours to paint with conventional tools.

Most professional spray equipment uses compressed air and is expensive and complicated. Sprayers for amateurs are airless; they merely pump liquid paint through a nozzle somewhat like that of a garden hose. Airless sprayers are affordable and easy to use after only a little practice.

As with all spray-painting equipment, safety and adequate preparation are crucial. Airless sprayers can deliver paint at speeds up to 200 m.p.h. and at pressures of up to 3,000 pounds per square inch.

This is sufficient to force paint through skin and into a person’s body, so it is vital that the tool be used carefully. Never point a sprayer at yourself or any person. Keep children and pets well away when spray-painting.

Unplug the sprayer before unclogging the nozzle or performing any other maintenance, and never leave a sprayer--plugged in or not--lying about unattended.

Wear safety goggles and a face mask or respirator when spraying. Be sure the mask or respirator is labeled effective against the type of paint being used.

In preparing to spray-paint, remove or cover all surfaces that should not receive paint, just as for any painting project. But because sprayed paint can drift onto more surfaces than drips or slop-overs from clumsy brush or roller work, the job must be done on a grander scale.

Indoors, cover window panes with newspaper or plastic wrap held on with tape. As with brush or roller painting, cover floors and ceiling fixtures, remove hardware, and mask molding.

Outdoors, protect windows, shrubbery and your car before spraying siding. Before spraying fences and other items that do not have solid surfaces, place a shield such as a large piece of cardboard behind the item, braced against a ladder. Spread plastic on the ground to protect the grass.

Start a painting project by setting up the sprayer according to the manufacturer’s directions. If you have never used a sprayer, first load it with water and spray against an outside wall or a scrap of plywood for practice.

The correct technique is to hold the sprayer upright, 10 to 12 inches from the surface to be painted, and move it back and forth in horizontal strokes about three feet in length, overlapping each stroke by about a third of its width.

Keep the nozzle parallel to the surface being sprayed by stepping from side to side. A common mistake is to swing the sprayer in an arc instead, which produces thin spots at the edges and deposits too much paint in the middle. Spray slightly beyond the edges of the area on each pass.

Before filling a sprayer with paint, strain out any lumps by pouring the paint through several layers of cheesecloth. Lumps can clog the nozzle. You may have to thin the paint by about 10% with water or paint thinner, depending on the type of paint. Check the manufacturer’s directions for specifics.

Experiment with the pressure control by using different nozzles to obtain the smoothest spray. Thin, even coats produce the best results. When finished painting, clean the sprayer thoroughly.