How to Clean a Nixie Tube and Clock Case Without Damaging It

Why you power off and unplug first

Before you clean any part of a Nixie clock, switch it off and unplug it from its power source, and give it a few seconds afterward before touching anything inside an open case. This matters for more than tidiness: as covered in Is Nixie Tube Voltage Dangerous?, the tube-driver section of the board runs at roughly 170–180V DC internally, generated from the low-voltage input by an onboard boost converter. On an assembled, closed-case clock in normal use that voltage is never exposed, so wiping down the outside of the case powered-off is straightforward. If the case is open — during DIY assembly, a repair, or simply because a case design leaves the board visible — treat any cleaning near the board with the same caution you would use around any other high-voltage circuit, and never clean it while powered.

Cleaning the tube glass safely

Nixie tube envelopes are thin glass, so the safest approach is also the simplest one. For everyday dust, a dry microfiber cloth is enough — wipe gently rather than scrubbing, since the glass sits close to fine internal electrodes and wire leads that don't need extra mechanical stress. For fingerprints or smudges that a dry cloth won't shift, dampen a soft cloth lightly with isopropyl alcohol (IPA) rather than water, and wipe rather than spray.

A few things to avoid: don't use household glass cleaners, ammonia-based sprays, or abrasive cloths and paper towels, which can leave fine scratches on glass over repeated cleanings. And never spray any liquid directly at the tube or into the case — apply liquid to the cloth first, not the tube, so nothing runs down into the socket or board underneath.

Cleaning the case

Case materials vary across the product range — wood, acrylic, and metal all respond differently to cleaning products, and what's safe on one can dull, cloud, or damage another. As a general rule, a dry or barely-damp soft cloth is the safest default for any case material until you know otherwise, and it's worth avoiding strong solvents or ammonia-based cleaners on any clear or semi-clear case material specifically.