Cleaning up a Spray Gun after Use

Paints and all types of paint-related products – including primers, clear coats, and so on – harden eventually, and leaving even fairly limited traces of any of these substances in your spray gun after you have used it is an invitation to reducing your favorite painting implement into a useless and more or less solid lump. Even if the dried paint can eventually be soaked out with solvent, a great amount of time and effort will be wasted performing a cleanup which could have been avoided by clearing the gun out initially immediately after use.

The first step in the process is to acquire the solvent that is offered as part of the paint system you are using. All complete paint systems should include plain, compatible solvent, both to further thin paints if necessary and, more commonly, for cleaning tasks such as this. These solvents should be bought at the same time as the paint, both to avoid any problems caused by reformulations occurring before you get the chance to use the paint, and to ensure that you do not begin spraying paint and suddenly discover that you have no available way to clean your spray gun.

Further techniques to clean up your spray gun after use include –

• Remove the paint cup, slosh some solvent around inside to carry out an initial cleaning, then fill the cup halfway with new solvent and spray it out of the gun exactly like you were applying paint. Repeat these steps several times until the solvent coming out of the air cap is clean and untinted, showing that most of the paint has been removed from the depths of the device.
• Remember that polyester primers are extremely resilient and harden in 25 minutes – probably beyond any hope of recovery. It is necessary to work fast when these products are involved.
• Some gravity-feed guns include disposable plastic liners for the paint cup. These are probably not the most environmentally sound items, so some painters may wish to dispense with them to avoid creating more pollution than the painting process already does. However, many will prefer the simplicity these liners add to cleaning, since there will be no rinsing of the cup necessary and you can go straight to spray-cleaning the gun.
• Once this has been done, take off the air cap and place it into a shallow tin of solvent, along with its associated retaining ring. The paint needle valve must be extracted by loosening the material control until it comes free, after which is should be washed in solvent and sparingly anointed with special paint gun lubricant at the places where the trigger contacts it.
• The interior can now be cleaned out with a pipe cleaner or slim brush, and the air cap ports opened with a wooden toothpick and some solvent. Do not use metal on the gun while cleaning it, since the gun’s performance depends on precise tolerances and even a slight scratch might result in drastic changes in the painting results.
• Even the humble toothbrush has a role to play in cleaning a spray gun. If paint got on the exterior, it should be wiped down with solvent and a clean cloth, with a toothbrush or similar small but relatively soft brush used for the more stubborn places.