Paint or corrosion can often cause the ball in the lower end of the pump valve to stick in place and stop progress. Typically, the fix for this problem is to tap the valve housing with a hammer to shock the ball loose. The Titan Impact 440, Titan XT 420, and Wagner pump (shown), however, have small plunge levers that free the ball with a little push – no hammering on delicate parts required.
Two of these three models also share another interesting feature, an auto-oiler. Pump seals, called packings, require a few drops of oil after each use. Most tools have a small opening at the top of piston housing to drip oil into (except for the Milwaukee, which has no provision for oiling seals at all), but on the Titan Impact 440 and Wagner tools, an oil tank in the top of the pump housing holds a good supply of oil, which is dispensed as needed by pushing a button. A window lets you keep an eye on the oil level.
Airless spray guns are like saw blades: A pro will often fit his favorite type to a new machine, while occasional users will just use the one that comes with the tool. Guns and hoses for these units all share a universal fit, so you could upgrade a lesser pump with a premium gun – but putting that $150 to $200 into a better unit that comes with a better gun is a wiser investment, especially at the price level of the tools in our test.
The Titan LX80II gun (shown) that comes with the Titan Impact 440 exemplifies everything we like in a gun. Four-finger triggers are preferable to two-finger versions for fighting fatigue (premium guns can be fitted with either kind of trigger). And only the lightest possible trigger pressure should be required. We like the Impact 440's all-metal safety switch parts, the hose swivel fitting, and the wide-open tip guard that doesn't collect paint and drip it back into the spray. This is a really big consideration because when a dollop of paint drops into the spray mist, it leaves a string of paint on the finished surface that the painter must wipe off and respray. To deal with a narrow guard that does this, the painter must routinely stop and wipe it with a rag. For this reason painters will sometimes just cut the guard off the gun.
The exploded view of the gun reveals the filter inside the handle. On all the guns except the Milwaukee and Wagner, the handle opens without tools, making it easy to access and clean. This filter is the final line of defense – after the suction tube screen and the pump filter – against a clogged tip. New filters cost about $5, and different versions are available for use with different coatings and tip sizes.
The replaceable tip is the T-shaped component visible at the top left, with the tip housing and guard assembly located just below. Tips come in a range of sizes and go by a common designation consisting of three numbers. Doubling the first number gives you the spray width in inches with the tip held one foot away from the wall; the next two numbers are the tip's orifice size in thousands of an inch. That means a common 517 tip – which is what our tester uses for most latex spraying – has a .017-inch hole and a useful spray width of 10 inches. The tips are called reversible because they can be rotated 180 degrees to blast out clogs; they can't deliver paint in both directions. The industry-standard tips for shooting latex paint go by the designation RAC 5, and the guns that come with most of our pumps fit these standard tips. The two higher-end Graco units ship with Graco's exclusive RAC X tips, but we swapped out the housing and tip so our painter could use his favored tips with each tool in the test. Graco claims that its pricey new tips last 60 percent longer than standard tips, but according to our painter and the local paint store, they have yet to be enthusiastically adopted by the trade.
Standard tips cost about $30 each and last for 15 to 40 gallons or so, depending on the abrasiveness of the clays and mineral pigments in the paint. As a tip wears, the fan shape of the spray pattern loses definition and eventually becomes inefficient. A blown-out tip also requires more output from the pump, which is why we specified tools that can shoot at least a .019-inch tip, even though .017-inch tips are more common.