How to Demagnetize a Watch: DIY vs Professional Fix

A watch that suddenly starts gaining several minutes a day after months or years of keeping good time can be concerning for any mechanical watch owner. It is easy to assume that something has gone wrong inside the movement. In many cases, though, the actual cause is something far more common and far more fixable: magnetism.

Modern life is full of magnetic fields that can affect a mechanical movement, from phone cases and laptop covers to bag clasps and speakers. A watch does not need to touch a magnet to be affected. The good news is that demagnetizing a watch is usually quick and non-invasive. The main question is whether to demagnetize it yourself or have a watchmaker handle it.

This guide explains how magnetism affects a watch, how to check for it, how to demagnetize a watch yourself, and when professional help is appropriate.

How Does Magnetism Affect a Watch

Inside a mechanical watch, the hairspring is a fine coiled spring that helps regulate how fast the balance wheel oscillates, which in turn controls timekeeping accuracy. When a traditional steel hairspring becomes magnetized, adjacent coils can attract each other and stick together. This changes the effective length of the spring and can cause the balance to oscillate faster than intended, making the watch gain time.

The practical result can be a watch that suddenly runs fast, sometimes by several minutes a day. Magnetism does not usually cause permanent damage to the movement, but prolonged or strong magnetic exposure can affect certain components and should not be ignored. It is often an external source of interference rather than evidence of a mechanical fault.

What Causes a Watch to Become Magnetized

Everyday magnetic exposure is more common than many owners realize, and the strength of the magnetic field matters. The table below shows some common sources of magnetic fields that can affect a watch.

Watches with modern anti-magnetic components, such as silicon or specially alloyed hairsprings, tend to resist this kind of interference better than older designs with traditional steel hairsprings. However, magnetic resistance varies by movement and model, and no mechanical watch should automatically be assumed to be completely immune.

A watch can become magnetized after a single strong exposure, while repeated exposure to strong magnetic fields can increase the risk.

How Do You Know If Your Watch Is Magnetized

Does a Magnetized Watch Show Obvious Signs

Not necessarily. A magnetized watch can look completely normal from the outside, which is part of why the problem is often mistaken for a more serious fault. The clearest sign is usually a sudden, noticeable change in accuracy, particularly the watch gaining minutes per day rather than losing time.

A few simple checks can help determine whether magnetism may be involved:

• The compass test. Place a compass on a flat, level surface away from other metal objects, then slowly bring the watch close. If the compass needle noticeably deflects as the watch is brought close, there may be enough magnetism present to warrant further checking. A smartphone compass app can work similarly, though results can be less consistent than a physical compass.
• Look for a sudden change in accuracy. If the watch was keeping reasonably accurate time and then abruptly started gaining several minutes a day with no other explanation, such as a recent knock or overdue service, magnetism is a common possibility worth checking.
• The professional test. A watchmaker can assess whether magnetism may be affecting the movement using timing equipment, while a dedicated gauss meter can directly measure magnetic fields where available.

A compass is useful as a rough indication, but it cannot tell you how much magnetism is present or whether magnetism is definitely the cause of the timing issue.

How to Demagnetize a Watch Yourself

A basic handheld demagnetizer is a common DIY tool for this job. These devices generate an alternating magnetic field that gradually decreases as the watch is moved away from the device. This reduces residual magnetism in the affected components.

Types of DIY Demagnetizers

Consumer demagnetizers generally come in a couple of common formats:

• Box or pad-style demagnetizers. The watch is held just above a flat surface where the field is generated. These are common, affordable, and straightforward to use for a single watch at a time.
• Loop or coil-style demagnetizers. The watch is passed through an open coil rather than held above a flat surface. This format allows the watch to pass through a clearly defined magnetic field.

Both formats work on the same basic principle, but the correct procedure depends on the specific device.

Using a Handheld Demagnetizer

1. Clear the surrounding area of other watches, tools, or magnetic objects, since the demagnetizer will briefly generate its own magnetic field.
2. Position the watch just above the demagnetizer’s surface, or pass it through the coil opening if using a loop-style device. Avoid direct contact unless the manufacturer’s instructions specifically allow it.
3. Press and hold the activation button while slowly moving the watch away from the demagnetizer, following the distance and technique recommended for the device.
4. Release the button only once the watch is clear of the active magnetic field, then set it down away from the demagnetizer itself.
5. Re-check the watch afterwards and monitor its accuracy.

If the problem persists after following the manufacturer’s instructions, it’s worth having the watch professionally checked rather than repeatedly demagnetizing it without further diagnosis.

A Few Things to Avoid

• Don’t use a strong permanent magnet to try to “cancel out” magnetism. This can magnetize the movement further rather than neutralizing it.
• Don’t place the watch directly against the demagnetizer unless the device’s instructions specifically say to do so.
• Don’t assume a demagnetizer has fully resolved the issue without checking accuracy afterward. A basic compass check only provides a rough indication.
• Don’t use a demagnetizer near credit cards or magnetic storage media, since the field it generates can affect magnetic strips or sensitive components.

DIY Demagnetizing vs Professional Servicing

If a mechanical watch suddenly starts running fast, a DIY demagnetizer can be a reasonable first step. Professional help is more appropriate when the cause is uncertain, the problem persists, or the watch itself is valuable or delicate. A watchmaker can also check whether another mechanical issue is affecting accuracy rather than assuming magnetism is the only cause.

Common Misconceptions About Demagnetizing a Watch

1. Does Demagnetizing Permanently Fix Accuracy Problems?

Not necessarily. Magnetism can cause a watch to run fast, but issues such as dried lubrication, a worn mainspring or poor regulation can also affect accuracy. If the watch remains inaccurate after demagnetizing, it may need further diagnosis or servicing.

2. Do Modern Mechanical Watches Need to Be Demagnetized?

They can, depending on the watch and its exposure to magnetic fields. Anti-magnetic components make modern watches more resistant to magnetic fields, but they are not necessarily completely immune. If a watch suddenly starts running fast after magnetic exposure, demagnetization may still be appropriate.

3. Can a Watch Become Magnetized Again After Demagnetizing?

Yes. Demagnetizing removes or reduces residual magnetism in the affected components, but it does not prevent future exposure. If a watch is repeatedly exposed to strong magnetic fields, it can become magnetized again after treatment.

How to Prevent a Watch From Becoming Magnetized

Once a watch has been demagnetized, a few simple habits can help reduce the chance of the problem returning:

• Keep the watch away from magnetic phone cases and tablet covers when possible.
• Avoid storing it directly beside speakers or other strong magnetic sources.
• Don’t place the watch directly on laptops or other devices with strong magnetic components.
• Be particularly careful with magnetic watch boxes, bags and accessories where the watch can remain close to the magnetic closure for long periods.
• If your watch has an anti-magnetic rating, follow the manufacturer’s stated limits rather than assuming it is completely immune.

You don’t need to avoid every electronic device in daily life. The main concern is prolonged or close exposure to stronger magnetic fields.

How Long Does It Take to Demagnetize a Watch

The demagnetizing process itself is usually very quick. A handheld demagnetizer can often reduce residual magnetism within seconds when used correctly, although the exact procedure depends on the device.

Professional demagnetization is also generally a quick procedure. However, the total appointment may take longer if the watchmaker checks the timing before and after treatment or finds another issue affecting accuracy.

What matters is not just how quickly the watch is demagnetized, but whether its performance is checked afterward.

When Should You See a Professional Instead of DIY

There are several situations where it is better to have a watchmaker handle the demagnetization:

• The watch is a valuable or vintage piece. A professional assessment avoids the risk of using an unfamiliar DIY tool on a valuable watch.
• A basic demagnetizer hasn’t resolved the issue. This may indicate that another issue is affecting the watch’s accuracy.
• You want confirmation the fix actually worked. A timegrapher can provide useful timing data, while a gauss meter can directly measure magnetic fields.
• The watch has stopped entirely rather than just running fast, since this can indicate a more serious issue that needs professional diagnosis.

What Happens During Professional Demagnetization

A professional demagnetization may start with a timegrapher check to assess the watch’s timing performance and determine whether magnetism could be contributing to the problem. The watchmaker will generally check the movement’s rate, amplitude, and beat error first. These readings can help identify abnormal timing behavior that may be associated with magnetism.

From there, the watchmaker uses a dedicated demagnetizer to treat the movement, then retests the watch’s rate, amplitude, and beat error to check whether the treatment has improved the watch’s timing performance.

Because the watch is being assessed professionally, a watchmaker can also check for other issues at the same time, such as dried lubrication, overdue servicing, or components showing early signs of wear. The demagnetizing itself might take only a few minutes, but the diagnostic checks can help determine whether magnetism is actually the main cause of the problem.

FAQs

1. Can a Watch Demagnetize Itself Over Time?

Residual magnetism may gradually dissipate over time, but this isn’t a reliable or predictable fix. Using a demagnetizer or having the watch professionally treated resolves the issue much more quickly.

2. How Much Does It Cost to Demagnetize a Watch Professionally?

This varies by watchmaker and whether other servicing is needed at the same time, so it’s worth checking directly with a service center for an accurate quote.

3. How Do I Know If My Watch Is Magnetized or Just Needs a Service?

A sudden shift toward gaining time, especially after exposure to phones, laptops, or speakers, can indicate magnetism. Gradual timing drift, a shorter power reserve, or a watch that’s overdue for maintenance may indicate that a service is needed. A professional check can help determine which applies.

4. Can a DIY Demagnetizer Damage My Watch?

When used according to the manufacturer’s instructions, a basic handheld demagnetizer is generally low-risk for a mechanical watch.

5. Are Some Watches More Resistant to Magnetism?

Yes. Watches designed with modern anti-magnetic components can resist magnetic exposure better than watches using more traditional components, although the exact level of resistance depends on the specific movement and model.

Final Word

A magnetized watch is one of the more common reasons a mechanical watch suddenly starts running fast, and fortunately, it is usually one of the easier problems to fix. A basic handheld demagnetizer can sometimes resolve magnetism-related timing issues at home, but it can’t confirm the cause or catch other issues that might be contributing to the problem. For anything beyond a simple DIY attempt, a professional check offers a more reliable answer.

Key Takeaways

• Magnetism can affect the hairspring and cause a mechanical watch to run fast.
• A basic DIY demagnetizer can sometimes resolve magnetism-related timing issues, but a compass only provides a rough indication of whether magnetism may be present.
• Demagnetizing doesn’t fix unrelated mechanical or servicing issues that may also affect accuracy.
• Keeping a watch away from strong magnetic sources can help prevent the problem from returning.
• If a demagnetizer doesn’t resolve the issue, or if the watch is valuable, overdue for service, or has stopped entirely, a professional check is the more reliable option.

If your watch has started running fast or you’re not sure whether magnetism is the cause, bring it to Watchlab. We specialize in watch repair and servicing and can diagnose the cause of the problem. Book your appointment today.