Airless Paint Machines for Large Painting Jobs
Although a crude variation of our modern-day airless painting machines were developed in the early 1900's, those early compressed air sprayers had some serious limitations. Today's airless sprayers use a pneumatic pump and high pressure to force paint through the gun's nozzle. If you have a really big paint job, such as the exterior of your home, consider renting an airless paint sprayer, or perhaps borrowing one from a friend or relative. Airless paint sprayers come in a wide variety of sizes, all the way from light-duty, suitable for a one-shot home painting to the heavy-duty industrial machines which are typically used by the painting contractor. To paint your home effectively, look for a medium-duty airless paint sprayer, but if you are only planning to paint a fence or perhaps one wall of your home, you can probably get by with a hand-held sprayer which can be purchased for under $100 at a home improvement store, or, in some cases, Wal-Mart or Costco. Unless you plan on painting several houses, you probably don't need to spend the $1000-$4000 to buy a professional airless sprayer such as a Graco.
The All-Important Spray Gun Tip
Whether you rent, borrow or buy an airless paint sprayer, the tip you use is crucial. Depending on the size of your paint job, the specific material you will be painting, and the thickness of the paint you desire, you will choose a tip based on the size of the opening and the width of the fan. The larger the opening, the more paint the tip will deliver, and the wider the fan width, the less paint the tip delivers. Don't forget that the airless paint sprayer will spray thinner paints like primer, or stains much more quickly than thicker paints. If you are having trouble with the paint coming out of your spray gun, consider using a tip with a wider opening before you resort to thinning the paint. Look carefully at the spray gun tip to ensure that the seal is properly placed, then insert it into the tip housing hole and connect the housing onto the spray gun.
The housing should be snug, to prevent leaking, yet you should still be able to manually turn the tip from a vertical to a horizontal position fairly easily. If you are completely new to painting with an airless paint sprayer, start with a tip size between 310 and 314, as they are the most "forgiving" for beginners. If you want to go a bit further into tip selection, then you will want to know that the first number represents the fan width (in inches) x 2. Therefore a 314 tip size would have a fan width of 6 inches, or a 112 tip size would produce a mere 2" of fan. The tips last two numbers represent the size of the opening-the larger the number the more paint you will have streaming out of your spray tip. Generally speaking, the smaller the tip, the slower the application rate, but the better control you will have. Smaller tips are usually reserved for fine finish work, while larger tips are best for thick paint or fast application.
If you neglect to cover up or mask off surrounding surfaces, windows and doors prior to painting with an airless paint sprayer, you will pay for the time saved in time cleaning up the mess. Make sure to move cars or outdoor furniture to a safe distance when using an airless paint sprayer, and don't attempt to spray the exterior of your house when the wind is blowing-even a little bit. Test your spray pattern before you start randomly spraying, and try out different tips until you are satisfied with the result. Your goal is to keep the spray gun moving constantly, and overlap each spray pattern by about fifty percent. Stay the same distance away from the surface you are painting at all times, and keep the gun pointed away from you-or anyone else at all times. It's a good idea to wear protective clothing and safety glasses, as well as an old hat. Finally, once you have finished the paint job, and it looks absolutely fabulous, make sure to clean the gun and tip thoroughly with water or solvent to prevent paint from hardening inside.