Cleaning a watch properly: with caution instead of water
Cleaning a watch properly is not a matter of force or aggressive agents, but of the right method for the particular model. The most common mistake is to treat every watch the same and simply hold it under the tap. That can get expensive, because a watch whose seals have aged or which was never built for contact with water lets moisture into the movement and rusts from the inside.
Gentle cleaning therefore starts not with water, but with a question and with the right tool. If you know whether your watch is water-resistant, and combine dry and wet steps in the right order, you keep the case, strap and crystal clean without risk. The following sections follow exactly this path, from water resistance through the tool list to the step-by-step instructions and the things you are better off leaving alone.
First clarify water resistance
Before even a drop of water comes into play, you need to know how water-resistant your watch is. Only a watch that is clearly marked as water-resistant and whose crown is firmly pushed in or screwed down may come into contact with a damp cloth or, under certain circumstances, a little water. If the caseback shows, for example, a rating such as 10 bar or 100 metres, the watch is in principle built to handle water, provided the seals are intact.
For vintage watches, models without any water resistance rating and watches whose last seal replacement was a long time ago, however, the rule is: clean dry only. Old seals become brittle, and a rating from the past says nothing about the present condition. When in doubt, always choose the more cautious option, because a watch cleaned dry stays intact, while one needlessly flooded can suffer expensive movement damage. This one rule is the most important in this article.
The right tools for gentle cleaning
For gentle watch cleaning you do not need special equipment, but a few soft helpers make the job easier and safer. First on the list is a soft microfibre cloth that leaves no fibres and no scratches. Added to that is a soft brush, such as a very soft toothbrush or a fine paintbrush, to loosen dirt from the gaps between bracelet links and from the edge of the bezel.
A blower is particularly useful, as you can use it to blow loose dust and grains of sand out of the bezel, the crown gap and the bracelet links before you even go over them with a cloth. That way you do not push hard particles across the case that would cause fine scratches. We present a simple, effective model in the article on the UES AB09 Blasebalg. You use lukewarm water with a tiny drop of mild soap only on confirmed water-resistant metal watches, and even then sparingly. A polishing cloth for metal surfaces, as described in the article on the Cape Cod Poliertüchern, rounds off the kit. Our Tools & Care section collects an overview of useful helpers.
Step by step: cleaning the case and bracelet
Once water resistance has been clarified and the tools are ready, it is best to proceed in this order:
- Blow off dust: Use the blower to remove loose dust and sand from the bezel, crown gap and bracelet links, so that no hard particles scrape across the case later.
- Check the crown: Make sure the crown is firmly pushed in and, for screw-down crowns, screwed fully down to the stop. Only then is the case protected during cleaning.
- Wipe the case and bracelet: Go over the case, bracelet and caseback with a dry microfibre cloth or, on water-resistant watches only, a slightly dampened one. The soft brush loosens stubborn dirt in the gaps.
- Clean the metal bracelet thoroughly (only if water-resistant): If the metal bracelet is removable and the watch is reliably water-resistant, you clean the removed bracelet with a soft brush in lukewarm water with a tiny drop of mild soap. The case with the movement stays out of it.
- Dry thoroughly: Pat all parts with a dry cloth and let them dry completely before the bracelet is refitted. Residual moisture in the bracelet links otherwise leads to stains.
How to remove and refit a bracelet cleanly without scratching the lugs is shown in the article Uhrenarmband wechseln. With the bracelet removed, a metal bracelet can be cleaned much more thoroughly and safely than when it is fitted on the wrist.
Leather strap: never into water
For leather straps there is one clear exception to everything said about water: a leather strap must never be immersed in water. Leather soaks up water, becomes hard and brittle as it dries, loses colour and begins to crack at the edges. A leather strap that has once been soaked and dried again can generally not be saved, which is why caution is especially important here.
For care, you wipe a leather strap only on the outside with a dry or very slightly dampened cloth and then let it air dry, never on the radiator or in the sun. Special leather care is rarely necessary, and if you use it, only very sparingly and exclusively on the outside. The inside, which rests against the skin, stays untreated. If a leather strap is stretched out or cracked despite care, replacing it is the more honest solution than any rescue attempt.
Cleaning the crystal: sapphire, mineral and acrylic
The watch crystal is usually cleaned quickly, but the right method depends on the material. Sapphire and mineral crystal are hard and scratch-resistant, and a soft microfibre cloth, slightly dampened if needed, removes fingerprints and streaks effortlessly. The only important thing is to blow off loose dust beforehand, so that no grain of sand grinds across the crystal under the cloth.
Acrylic crystal, as fitted to many vintage watches and some classics, requires more care because it is softer and therefore more prone to scratching. Acrylic does have one advantage, though: fine scratches can be polished out, which is not possible with sapphire. How to do this gently with a suitable polish is described in detail in the article Acrylglas polieren. In every case, keep rough cloths, paper tissues and abrasive agents away from the crystal, as they leave exactly the scratches you want to avoid.
What you should never do when cleaning
A few actions do more damage than any dirt, and you should consistently avoid them. Never hold a watch under running tap water without having reliably clarified its water resistance, and never pull the crown out under water or with wet fingers, because in the pulled-out position the way into the movement is open. Also avoid aggressive cleaners such as glass cleaner, alcohol, acetone or scouring agents, which attack seals, coatings and dials.
Your own ultrasonic bath is also not a good idea for the complete watch: the fine vibrations can harm delicate components and aged seals. A professional may clean a removed, water-resistant metal bracelet in an ultrasonic bath, but the watch with its movement does not belong there. If you are unsure with a valuable or old watch, leave the thorough cleaning to the watchmaker, who can check the seals at the same time. You will find suitable care helpers for safe cleaning at home gathered in the Tools & Care section.
Magnetism is not dirt
Finally, one point that is often confused with dirt but has nothing to do with it: if a mechanical watch suddenly runs much fast, it is almost never down to dirt and no cleaning will fix it. Usually the movement has become magnetised because the watch lay too close to a speaker, a tablet or a magnetic clasp. This is not a defect and not a care mistake, but a matter of demagnetising.
How to tell whether your watch is magnetised, and how to fix it again with a simple demagnetiser, is explained in the article Watch magnetised: how to spot and fix it. Cleaning and demagnetising are therefore two separate topics, and it helps to keep them apart. Our knowledge section collects further guides on care, technology and storage, so that your watches stay not just clean but in good shape all round.