There are many reasons to recommend these types of machine as well. First of all they’re lighter because there is no paint pot. You simply use the 5 gal. bucket that the paint comes in and set it right on the machine. There’s no air compressor, either, because you don’t need air to “push” the paint. Instead a suction tube placed right into the paint bucket sucks the paint up – i.e. “draws” the paint – to the pump. This paint gets pumped so hard it’s forced to go through a 25-ft. hose and into the gun. That’s it; an engine, motor, pump and one gun.
The airless machine has no paint pot and is lighter weight. But that doesn’t mean you can just roll the machine up onto the trailer and drive away like you can with a conventional machine. If you do, paint will splash (you’re spraying from an open 5 gal. bucket of paint) causing a huge mess.
The solution is to either clean the machine before you travel – even if you have two “yellow” jobs back to back, five miles apart – or simply cut a hole in the plastic lid that came with the paint bucket. Snap this lid back onto the paint bucket – around the suction tube – and then drive away. I do this. I love it. I’ll clean it later.
Because an airless machine has no air compressor you cannot adjust for the thickness of the paint. But rarely is the paint too thick or too cold. Without the introduction of air the paint is “stuck to itself” and won’t “break up.” This means it won’t fan out and produces a maximum line width of 2 in. And don’t try lifting the gun higher…it won’t work. It doesn’t matter if you hold the gun 2 ft. off the ground, you’re only going to get a 2-in.-wide line. And don’t buy a tip that’ll spray an 8-in.-wide line just to get a 4-in. wide line. Save your money.
The fix? I’ve heard that adding a couple of cups of thinner to oil-based paint or a couple of cups of water to water-based paint will do the trick. Read the paint can on how much you can “reduce” or “thin” the paint.
Don’t get me wrong, I love that the airless is lighter, but on a conventional machine you can adjust the air pressure to the gun, introducing more air to the gun – not the paint pot. This atomizes, or "breaks up" your paint, allowing you to produce a wider line. You can also simply “reduce” this paint, just like on the airless machine.
Did you notice that to get an 8-in. line with an airless machine you need a different tip? This cost can be somewhere between $20 and $40. To save some money spray two 4-in. lines side by side for an 8-in. line and six 4-in. lines side by side for a 24-in. Stop Bar. Conventional spray machines don’t have different tips. The widest line for a conventional unit is about 6 in. (so spray lines side by side to get widths from 8 to 24 in.).
The lighter weight of an airless machine also means that if you do hit a small dog or a small walnut while striping, the machine is not as forgiving…it will wiggle. Not a big deal but this wiggle will translate out to the gun and shake. Make sure the gun is tucked close to the machine and as low as possible to alleviate almost all shake...and keep an eye out for small dogs.
A Stenciling Difference
Stenciling with an airless can be tricky because there's no way to spray “easy”...pull the trigger and it’s all on. Spray five handicap stencils in a row with all-on power and the stencil itself is sloppy and paint will drip from it. The fix?...spray a few stencils then let the stencil dry. Go spray some lines. Come back and spray some more stencils or wipe the stencil off.
But spraying stencils is a little easier with a conventional striper because you can pull the trigger half way and control the volume of paint. It’s also easier when you have to touch up a curb with your stencil gun. Try touching up a curb with all-on power!
Air & Airless Maintenance and Cost
In general, airless machines aren’t as easy to work on as conventional striping machines and the replacement parts can be a little pricey. The hydraulic motor, for example, could cost $1000 to replace. Mine, however, is 12 years old, I use it almost every day and it is still going. If it breaks I will spend the $1000.
But I couldn’t spend $1000 repairing a conventional machine if I tried. Engines are $400 and compressors are about the same. Everything else is either a valve, hose or gauge and these are only $5 to $40.