Without the right equipment and spray tips, you can't do your best job. If you are trying to paint your home's exterior with a hand-held cup gun, you'll be frustrated by lunch time. You won't have much done because hand-held sprayers hold about a quart of paint at a time and often can't efficiently spray heavy-bodied exterior house paint. For anything larger than a deck or perhaps a small shed, use a larger airless sprayer that pulls paint straight from a 5-gallon bucket and has the power to apply it quickly and evenly to the surface.
Spray tips come in a wide range of sizes. Choose a tip with a smaller opening to spray thin materials like stain or the finish will be uneven. For heavier materials like latex paint or block-fill, use a tip with a larger opening. You can also use fan tips, which are available in widths from 4 inches to 12 inches. However, unless you're spraying large, flat expanses such as the inside of a newly constructed home, it will be difficult to have good control with a 12-inch spray pattern. You’ll need a much narrower fan for spraying interior trim or a wrought-iron fence. The staff at a paint store or rental yard can recommend the correct tip for your needs.
No matter how good your spray-painting technique, the result will be sloppy job if you don’t cover and mask everything. Over-spray can drift for quite a distance. Make sure everything in the area is covered or masked off.
Prepare the material for spraying by following the directions on the label. Some materials should be applied straight from the can without thinning, while others should be thinned. Sometimes it’s best to thin the first coat of paint with about a pint of water or solvent per gallon for absorbent surfaces. Spray the second and final coat without thinning it. It’s also a good idea to strain your paint, even if it’s a brand new can. You’ll be surprised at how much grit you’ll find, especially in cheap or “builder” latex paints. Without straining, such paint can repeatedly clog up the filters and tips. Use a mesh strainer or pantyhose.
One of the golden rules of spraying is to keep your hand perpendicular to the surface, instead of arcing it back and forth. Keep the spray gun rigid and move from your elbow or shoulder. Start moving the gun just before you pull the trigger, and release it just after you complete the stroke. Keep the spray tip between 12 and 18 inches from the surface. A good rule of thumb is the thicker the material and the higher the pump pressure, the farther away you should stand from the surface you’re painting. Work from top to bottom.
Use a light touch; it's always preferable to have two light coats than one heavy one. It's easy to fill in light spots later. If you get the paint on too heavily and it runs, don't brush it out because that leaves a mess. Use a dry roller to blend it in with the surrounding surface.