How do I clean an airbrush properly?

An airbrush is a device with a passage narrower than a hair, and every problem it develops starts as paint drying somewhere inside it. The difference between an airbrush that behaves for years and one that spatters constantly is almost entirely a matter of a two-minute routine at the end of each session rather than anything expensive.

Safety

What you'll need

• Cleaner matched to the paint — water-based cleaner for acrylics, lacquer thinner for lacquers
• Interdental brushes and cotton buds
• Wooden cocktail sticks
• A cleaning pot or a jar with a rag in it
• Nitrile gloves

Step by step

1. Empty and wipe the cup while the paint is wet.Tip the leftover paint out, then wipe the cup with a cotton bud or a folded piece of kitchen roll. Removing wet paint takes seconds; removing it dry takes solvent and a brush.
2. Flush cleaner through until it runs clear.Fill the cup with cleaner, spray it into a cleaning pot or a rag until what comes out is colourless. Repeat with fresh cleaner if the first pass comes out heavily coloured.
3. Back-flush to clear the paint channel.With cleaner in the cup, block the air cap with a gloved finger or a rag and pull the trigger. Air is forced back up the paint passage and bubbles in the cup, agitating the channel behind the nozzle where the flush alone does not reach. Do it briefly and gently, and never with your face over the cup.
4. Loosen the needle and withdraw it backwards.Unscrew the handle, slacken the needle chuck, and draw the needle straight back out of the rear of the body. Never push it forwards through the nozzle — that is how nozzles split and needle tips bend.
5. Wipe the needle from the rear towards the tip.A cloth or kitchen roll damped in cleaner, wiped along the needle in one direction from the thick end to the point. Wiping towards the tip and off avoids catching and bending it.
6. Clean the caps and the nozzle face.The inside of the air cap collects a ring of dried paint that deflects the spray. Soak the caps in cleaner and brush them out. Wipe the outside of the nozzle with a cotton bud.
7. Refit the needle carefully and gently.Slide it in from the rear until it seats in the nozzle. Push it home with light finger pressure only, then tighten the chuck. Forcing it home is the other way people split a nozzle.
8. Do a full strip occasionally.Nozzle removed, paint channel brushed out with an interdental brush and cleaner, needle packing checked. Monthly for regular use, or straight after a session with lacquer or metallics, which dry hard and fast.
9. Lubricate the needle lightly on reassembly.A trace of airbrush lubricant on the needle where it passes through the packing keeps the trigger smooth and stops the packing drying out. Use airbrush lubricant, not oil, which can contaminate paint.

Tips

• Buy the cleaner that matches your paint chemistry. Water-based cleaner will not shift cured lacquer, and lacquer thinner will attack the rubber seals in some airbrushes.
• An ultrasonic cleaner is genuinely effective on caps, nozzles and small parts, but do not put a whole assembled airbrush in one — it can damage seals and packing.
• If you cannot finish cleaning immediately, stand the airbrush with cleaner in the cup rather than leaving it dry. Rescuing it later is then a flush rather than a strip.

Common mistakes

• Cleaning only between colours and never at the end — The flush clears the cup and the front of the channel. It does not clear the film building up around the needle and behind the nozzle, which is where the eventual blockage forms.
• Soaking the whole airbrush in solvent overnight — It attacks the rubber and PTFE seals and the needle packing, and it swells or dissolves any plastic parts. Soak the metal front-end parts only.
• Poking the nozzle with a needle file, pin or drill bit — The nozzle bore is precision-formed and softer than the tool. Once it is scored or opened out, the spray pattern is permanently wrong and the part has to be replaced.

If it doesn't work

Questions people ask