How to Clean a Spray Gun with Xylol

A spray gun left with dried paint in it is a ruined tool, and xylol (xylene) is one of the best solvents for bringing one back, especially after oil-based or industrial coatings. Because xylol is strong and slow to evaporate, it dissolves the fresh and semi-cured paint that milder cleaners leave behind. Here is how to clean a gun with it without doing harm.

You will need xylol, a well-ventilated space, chemical-resistant gloves and eye protection, a spray-gun brush set, and a waste container.

1. Empty and depressurize. Release any air pressure, empty the cup, and back off the fluid adjustment.
2. Flush the passages. Pour a little xylol into the cup and spray it through into a waste container until it runs clear, cutting the paint out of the fluid path.
3. Disassemble the front end. Remove the air cap, fluid nozzle, and needle following the gun’s manual, then soak the metal parts in xylol.
4. Brush the details. Work the soaked parts with a soft brush, paying attention to the air-cap holes and the nozzle seat, where dried paint hides.
5. Wipe and inspect. Wipe everything down, hold the air cap to the light to confirm the holes are clear, and look for any paint you missed.
6. Reassemble and do a final pass. Put the gun back together and spray a last small charge of clean xylol through to confirm a clear path.

A few cautions matter here. Xylol can swell or harden some rubber seals and O-rings, so check the manual, since a number of manufacturers specify a milder solvent for the packings. Do the work with strong ventilation and away from any flame or spark, and do not soak plastic gun parts in xylol without first confirming they can take it. Let cleaned parts flash off before reassembly, and save the used, paint-laden solvent for hazardous-waste disposal rather than the drain.