CLEAN A BLOCKED AIRBRUSH NOZZLE

I’m having trouble with my airbrush, and I suspect the problem is caused by acrylic paint deposits trapped in the nozzle. I keep my airbrush as clean as possible, but reaching inside the tiny nozzle is difficult. Do you have any tips? Matthew Armstrong,

George says: Cleanliness really is vital to keeping airbrushes in fine fettle. Regular flushing during work sessions – and a thorough clean at the end of a job – are essential to ensure that the tool will work properly in future.

The ease with which an airbrush can be cleaned and maintained depends very much on the tool’s design. Some are better than others and the shorter distance the paint flows through the tool, the better – meaning there’s less area to clean! Any nooks and crannies or awkward bends in the paint channel inevitably increase the risk of clogging.

Acrylic paints can be especially prone to clogging, thanks to their rapid drying characteristics. Any lumps in the paint will also cause problems, which is why straining paints through a filter before loading is a good idea, especially if the paint has been sitting around for a while.

Flushing the airbrush with a cleaning fluid at regular intervals during painting greatly reduces the risk of clogging. There are various formulas available, some of which are tailored to acrylic and/or enamel paints. Cellulose thinners or Liquid Reamer are stronger solvents, which will soften and shift virtually any types of paint, but they must be used in a well-ventilated space and while wearing a facemask.

After a few flush-throughs with the cleaner, wiping out the inside of the paint cup between each flush, reload the cup about a quarter full. While wearing eye protection and with the airbrush kept away from your face, cover the nozzle and depress the trigger. This will force the air and cleaning fluid back into the paint cup, causing bubbling (hence the risk of the solvent splashing into your eyes). This also helps dislodge any paint debris from within the nozzle.

Repeating this a few times, until the cleaning fluid remains clear, is usually sufficient to clear most blockages. You can also repeat the process after removing the airbrush’s needle. Be extra careful here, as the bubbling of the cleaning fluid will be more lively!

If the problem is not solved and the airbrush continues to appear blocked (poor paint flow and bubbling in the paint cup while spraying), the nozzle will need to be removed and cleaned. Soaking it in cleaning fluid should help soften any deposits, which can be removed with a fine interdental brush.

If even this doesn’t cure the problem, an airbrush nozzle reaming tool might solve it. These super-fine tools act by scraping the inside faces of the nozzle, but I’d recommend using such a device only as a last resort. Airbrush nozzles are precision elements, designed to suit the profile of the needle exactly, so any physical interference with a metal reamer runs the risk of disturbing this setup.

Once cleaned, refit the nozzle, using a suitable thread sealant (available from airbrush suppliers) and avoid over-tightening. Lubricating the needle is also recommended, again using a special formula available from airbrush suppliers. This prevents the needle sticking and helps it move freely, making it easier to regulate paint flow.

George Dent MR’S editor and chief model maker can offer advice on almost any subject.

Paul Chancellor Paul is the proprietor of the well-known railway photographic archive Colour Rail.

Peter Marriott Scenic guru! Knows what’s available and how to use it.

This comprehensive cleaning and maintenance kit from Iwata includes almost everything you need for servicing airbrushes from a range of brands. GEORGE DENT

With the nozzle removed, it doesn’t hurt to clean out the airbrush interior with a fine pipe cleaner and a little cleaning fluid. It’s surprising how much paint residue can be removed from an ostensibly ‘clean’ airbrush! An airbrush nozzle reaming tool is a cheap emergency device to keep on hand, in case the soaking and dental brushes fail to clear the blockage. The finely ground tip is shaped to allow it to fit right into the nozzle.

GEORGE DENT

1 If, after flushing your airbrush, there’s still a blockage, quarter-fill the paint cup with cleaning fluid. Cover the nozzle and gently depress and pull back the trigger. The air will blow back into the cup, causing bubbling and forcing any debris out of the nozzle. Don’t blow the contaminated fluid through the airbrush – pour it into a waste container and clean out the paint cup. Repeat until the fluid remains clear and keep the air pressure to 15psi max.

Gently push the reamer tool into the nozzle and rotate slowly. Avoid exerting pressure against the end of the nozzle, as the tiny aperture may be damaged, especially on lower priced airbrushes that generally use less resilient metals.

Any paint debris will be visible on the end of the reamer. When satisfied that the nozzle is clean, add a little sealant to the thread (Iwata’s beeswax-based formula is recommended) and re-fit. Don’t overtighten. Add a drop of lubricant to the needle before slotting it into place.

Remove the nozzle from the solvent and clean the interior with an interdental brush. If more than a trace of paint is dislodged, it may be worth re-soaking the nozzle and repeating the process. 5

Drop the nozzle into a jar, submerging it with cleaning fluid. I used cellulose thinners, which will break down almost any type of paint. Leave to soak for an hour or two.

If the problem persists, we may have to remove the airbrush’s nozzle. Depending on the tool’s design, a small wrench may be required (usually supplied with an airbrush).

Airbrush cleaning fluids come in various formulas, aimed at different kinds of paint. Cellulose thinners and Liquid Reamer will shift virtually all paints, but they must be used with care. GEORGE DENT Keeping your airbrush clean and well-maintained is essential. It doesn’t have to be an onerous task and having a few simple tools and cleaning fluids on hand makes the job easy.