Airless paint sprayers come in many different configurations and designs but all have the same general features and controls. The basic idea behind how a sprayer works is that it pumps the paint and forces it out a very small tip on the spray gun. There is no air or air compressor involved, hence the name “airless” paint sprayer. They will apply a lot of paint very quickly and can make a tedious job very easy and quick.
Here are some spray techniques and pointers to get you started.
Don’t spray-paint when the air temperature is below 45 degrees or above 75 degrees.
Don’t spray-paint in direct sunlight, either. Too much heat dries the paint too fast, and it won’t bond well. If it’s too cold, the paint dries too slowly, attracting bugs and dirt, and the gun is more likely to clog.
1. Clear the work area of tripping hazards or objects that may snag the sprayer hoses.
2. Prepare the surface for painting. Cover any and all things that are not to be painted, including yourself. When spraying, there will be misting/fogging and this paint will end up everywhere. It has the same characteristics as fine sheetrock dust and will float and settle. Light synthetic coveralls should be worn along with spray hood, safety glasses and respirator.
If painting inside, cover/mask floors, walls, light fixtures, doorknobs, hinges, light switches, etc. If painting outside, the paint you spray 15 or 20 feet up onto a second story can float and carry in the wind. Cover all landscaping, neighbors’ house, fences, etc.
Always stir paint well and then strain it to prevent clogs in the tip or at any internal filters.
Always keep the spray gun pointed at the surface to be painted and keep it moving in a horizontal motion. Never spray without your hand in motion.
Start moving the gun before you start spraying and keep the gun moving in long, straight strokes. Sprayers apply paint quickly, so you must use this technique to get an even coat that doesn’t run. Move as fast as you would brush out a stroke, or 2 to 3 feet per second.
Hold the paint gun nozzle perpendicular to and 10 to 12 inches away from the surface. Even a slight change in this distance significantly affects the amount of paint being applied: If you hold the nozzle twice as close to the surface, you apply four times as much paint. Avoid tilting the sprayer downward or upward, which causes spitting and results in an uneven application.
Keep the nozzle perpendicular to the surface as you move it back and forth. The natural tendency is to swing the gun in an arc, which results in an uneven “bowtie” application.
Overlap each pass half the width of the spray coverage area to avoid leaving light areas or creating stripes.
Test and adjust the spray equipment until you produce the pattern you want. If the pattern is too narrow, you could apply too much paint to the area, resulting in runs. With a pattern that’s too wide, you have to make more than two passes to get good coverage. A pattern that’s 8 to 12 inches wide is adequate for most large surfaces.
It’s better to put on the paint a little light and go back and apply a little more than to load the surface with a coat of paint that’s too heavy and may sag and dry unevenly. In time, a heavy coat may peel.
( Note when using paints or other coatings, proper spray tip selection is important. If the maximum pressure setting is reached and the spray pattern still is not suitable, you may have the incorrect tip size or the tip may be worn and has to be replaced – see spray tips or troubleshooting under Paint Sprayer Operation for more information. )
Spraying the corners:
Do the corners and any protrusions first and finish up with the large, flat areas. Spray corners with a vertical stroke aimed directly at the corner. Move a little quicker than usual, especially on outside corners, to avoid overloading the edges.
After you complete each area, stand back and look for light spots or missed areas. Touch up, making sure that you move the gun before spraying. Keep a brush or roller handy for touch-ups.
Most sprayers have a tip guard to protect you from injecting yourself with paint. Remove your finger from the trigger and wipe off the guards occasionally — with a rag, not your finger. Paint buildup at the tip may affect the spray pattern.
Some spray applications require back-brushing or back-rolling — that is, brushing or rolling in the sprayed-on finish to get a more even coat and better penetration. The sprayer, then, is just a fast way to get the paint to the surface. In particular, you should back-brush stain applications on unfinished or previously stained wood. Back-brushing is strongly recommended when applying primers and sealers as well.
Clean the sprayers:
When you are finished painting, thoroughly clean the sprayer. All the paint must be cleaned out after each use.
Once you have completed your paint spraying task, fill a bucket with paint thinner if you painted with oil-based paint, or water if it was latex-based. Remove the intake hose from the paint sprayer and place it in your bucket of liquid. Trim the length of your old paintbrush to 1 inch—you will need this later. Put on your gloves and gather the rest of your equipment before you begin.
Any left over paint in your gun can be saved by shooting the gun into the paint can to release any paint still left within it. Be careful not to release any paint thinner into the can. Taking an empty second bucket, spray the remaining liquid until you get a clear and clean spray.