Your watch was fine last week. Now it's gaining five, ten, twenty minutes a day — not drifting, sprinting. Before you book a service or assume the worst, know this: the most common cause of a mechanical watch suddenly running fast is also the easiest to fix. It's magnetism, and the repair takes about a minute.
What's happening inside the movement
A mechanical watch keeps time with a balance wheel and a hair-thin spring — the hairspring — that breathes in and out, regulating each tick. That spring is metal, and metal can be magnetized. When the coils of the hairspring pick up a magnetic charge, they start sticking to each other. A spring whose coils cling together behaves like a shorter spring, and a shorter spring oscillates faster. Faster oscillation, faster watch. The watch isn't broken; it's been quietly pulled out of tune by a magnet it met in daily life.
Where watches meet magnets
Modern life is full of them: the magnetic clasp on a handbag or tablet cover, phone and laptop speakers, fridge doors, magnetic phone mounts, bag closures, even some desk accessories. The exposure is usually brief and unnoticed — set your watch down beside a tablet cover overnight and that can be enough. Mechanical watches are the vulnerable ones; a sudden sprint is one of the most common reasons a perfectly healthy watch ends up on a watchmaker's bench.
How to check
The classic test costs nothing: hold a simple compass near the watch and move the watch slowly past it. If the compass needle deflects as the watch passes, the watch is magnetized. A watchmaker can confirm it on a timing machine in seconds — a magnetized watch typically shows a rate that's wildly fast — but the compass tells you enough to try the fix first.
The 60-second fix
A demagnetizer undoes the charge by exposing the watch to an alternating magnetic field that fades away, leaving the metal's magnetic pull scrambled back to neutral. Using one is genuinely simple — it's the tool we carry in our Tools & Care collection as The Demagnetizer:
- Plug in the demagnetizer and hold the watch a centimetre or two above its surface.
- Press and hold the button, then lift the watch slowly and smoothly straight up and away — a slow draw over several seconds.
- Release the button once the watch is well clear.
- Repeat two or three times, then re-check with the compass and wear the watch for a day to confirm the rate.
That's it. Most magnetized watches return to their normal rate right away, because nothing was ever damaged — the spring just needed its coils unstuck.
When it isn't magnetism
Honesty matters here: demagnetizing fixes magnetism, and only magnetism. If your watch still runs fast afterwards — or runs slow, stops, or changed behaviour after a drop — something else is going on: it may need regulating, it may have taken a knock, or it may simply be due for service. A demagnetizer is the right first step because it's quick, harmless and costs nothing once you own one; it is not a substitute for a watchmaker when the problem is mechanical.
Keeping it from happening again
You can't avoid magnets entirely, but distance is cheap: don't rest your watch on tablet covers, speakers or laptop palm rests, and keep it a few centimetres from magnetic clasps in your bag. Habits beat hardware. And if it happens again anyway — it probably will — you now know the sixty seconds it takes to fix it. Browse the rest of the Tools & Care collection for the other small tools that keep a collection running between services.