David Dalton of Sprayers Plus — a supplier of spray tools for a wide range of uses — suggests the following pertaining to sprayer care and maintenance:
Sprayers are not storage containers, he says. They should be emptied at the end of the day and the gun flushed with at least one-gallon of water. Failure to do this will result in a much shorter life for the sprayer. Clean your spray tips daily while in use.
To keep sprayers working like new, you must lubricate seals and O-rings. “When the trigger gets stiff, lubricate it,” he says. The spindle is located on the gun, and it takes about 10 seconds to remove and lubricate the rings and seals. Some companies only have one O-ring in their sprayers, but his has two. The only lubrication you should use is 100 percent food-grade silicone, he adds, which Sprayer Plus includes with every unit.
The compression chamber has a large O-ring on the outside of the pump that moves up and down. If you lose or cannot build pressure, check this O-ring, as it’s probably dry. Lubricate it with the silicone mentioned above. On the bottom of that pump you’ll either have a mushroom check valve or an antenna that also should be lubricated.
Finally, a backpack unit will have a large round seal at its top. This should be lubricated periodically as it needs to stay pliable to maintain a good seal. If it dries out and becomes hard, it will leak when you bend and the tank is tipped, and chemicals will run down your neck. “Who needs that?” Dalton asks.