How to Clean Your HVLP Paint Gun

You can tell a lot about a person by how they treat their workspace and tools. The same can certainly be said about how a painter maintains their paint gun. After all, modern HVLP (High Volume Low Pressure) paint guns are precision tools that count on clean surfaces and optimized airflow to deliver a perfect sprayout.

A neglected spray gun can quickly become unreliable as paint hardens inside it, taking away the ability to make fine adjustments that control atomization. Simply put, proper cleaning of an HVLP paint gun is crucial to ensure optimal performance and longevity and should considered part of the overall paint process.

Below is a quick guide on how to clean an HVLP paint gun when spraying solvent-based primers and paints, including lacquers, urethanes, and epoxies typically used in automotive refinishing.

Materials Needed

• Cleaning solvent such as acetone or lacquer thinner
• Paint gun cleaning kit or small cleaning brushes
• Clean rags or paper towels
• Safety equipment (gloves, safety glasses)
• Sealable waste container
• Parts washing tub or tray 

Cleaning Steps

Safety First

You’re going to be working with volatile solvents. Always work in a well ventilated space with no open flames present. Wear safety glasses and solvent-resistant nitrile or latex gloves at all times to protect yourself from solvents and paint residues. Have a sealable waste container – an old paint can works fine – on hand to contain the cleaning fluid as you work.

Prepare the Gun for Cleaning

Disconnect the gun from its compressed air source and remove the pressure regulator. Remove the paint cup and empty the contents into your waste container. At this point you can clean and wipe the paint cup with your solvent and a rag, cleaning it both inside and outside before moving onto the rest of the gun.

Disassemble and Flush the Gun

Remove the air cap, fluid nozzle, and needle according to the disassembly instructions specific to your gun. Use a small spray bottle to force your cleaning solvent through the passages of the disassembled paint gun. Alternatively, you can use an aerosol-injected solvent to do the same thing more easily. Hold the gun over you waste container to catch the solvent, spraying until the solvent comes out clean.

Clean the Air Cap, Fluid Nozzle and Needle

In a small cleaning tub or tray, place the air cap, fluid nozzle, needle, and any other small internal parts. Cover them with enough clean solvent to let them soak. Use a cleaning brush to remove any dried or caked-on paint from the air cap and fluid nozzle. Be gentle to avoid damaging the components. Wipe the needle with a clean rag soaked in solvent, being careful not to damage the tip.

Reassemble the Gun and Test Spray

Once all components are clean and dry, reassemble the paint gun. Make sure each part is correctly aligned and tightened according to the instruction manual for your gun. Pour a small amount of solvent into the paint cup and connect it your compressed air source. Run a test spray with clean solvent to ensure that no residue remains in the paint passages.

Storage

Before storing the gun, wipe it down one last time and let it dry completely. Store the clean and dry paint gun in a safe place, preferably in its carrying case or another protected environment.

Additional Advice

• Always clean a new paint gun before its first use. This will remove any manufacturing oils or machining residue that could contaminate your paint job.
• It is NOT necessary to clean the paint gun between coats of the same material. However, any time you’re changing between materials (primer to base coat, for instance) you will want to thoroughly clean your gun – and probably change your nozzles.
• Do not let paint dry in the gun. Most paints have a working time of 3-4 hours depending on conditions. As soon as you’re done spraying, work on cleaning up your equipment.
• If you have a choice between acetone or lacquer thinner, we recommend acetone. It is safer to use, evaporates quickly, and leaves no residue.
• Disposable cup liners make cleanup quicker and easier. Once you’ve tried these, you may not go back putting paint directly in the cup.