How often should I have my preowned watch serviced and what does it involve?

A preowned mechanical watch should generally be serviced every five to eight years, although it may need attention sooner if its service history is unknown, its accuracy changes, the power reserve reduces, or there are signs of moisture or damage. A quartz watch usually needs less frequent movement servicing, but its battery, gaskets and water resistance should be checked when required. Older watches, heavily worn watches and complicated movements may also need a more individual service plan.

If you have recently acquired a preowned watch without reliable service records, it is sensible to arrange an assessment rather than relying solely on the seller’s description. A watch can appear to be running normally while having dried lubricant, worn components or compromised seals. Establishing its condition at the outset helps prevent avoidable damage and gives you a clear maintenance record for the future.

When should a preowned watch be serviced?

• At the recommended interval: Mechanical movements require periodic cleaning and lubrication because oils can deteriorate over time. The appropriate interval depends on the movement, its age, how often it is worn and the manufacturer’s guidance.
• When the service history is uncertain: If there is no dated invoice or dependable record, an inspection can identify whether servicing is advisable. This is particularly important for a valuable watch that has been stored for a long period.
• When timekeeping changes: Noticeable gains or losses, inconsistent accuracy, stopping during normal wear or a reduced power reserve can indicate that the movement needs attention. Magnetism, impact or an incorrectly set watch can also cause these symptoms, so a professional diagnosis is needed.
• After water or impact damage: Condensation beneath the crystal, corrosion, a loose crown or a significant knock should be treated promptly. Do not continue wearing a watch that may have taken in moisture.
• Before demanding use: If you plan to swim, travel extensively or wear the watch daily, arrange a condition and water-resistance check before relying on it in those circumstances.

Water resistance is not permanent. Gaskets age, crowns can wear and seals may be disturbed during battery replacement or other work. A water-resistance test is therefore useful even when the movement itself does not require a complete overhaul. The test should be appropriate to the watch and its stated rating; a water-resistant watch should never be assumed to be suitable for swimming unless its condition and specification have been confirmed.

What does a full mechanical watch service involve?

1. Initial assessment: The watch is examined externally and, where appropriate, its winding, setting, timekeeping, power reserve and visible condition are recorded. The case, crystal, bracelet, clasp, crown and pushers are checked for wear or damage.
2. Movement inspection: The movement is assessed to identify worn, damaged or non-original components. This helps determine whether a routine service is appropriate or whether additional repairs are needed.
3. Controlled disassembly: The movement is carefully taken apart so that individual components can be inspected properly. Complicated movements may require additional stages and specialist handling.
4. Cleaning: Components are cleaned using suitable equipment and methods to remove old oils, dirt and debris. Cleaning alone does not correct wear, so parts that no longer meet the required condition may need replacement.
5. Replacement of worn parts: Damaged or excessively worn components, along with appropriate gaskets, may be replaced. Parts should be selected for compatibility with the movement and the intended restoration standard.
6. Lubrication and reassembly: The movement is reassembled with the correct lubricants applied to the relevant points. Too little, too much or the wrong type of lubricant can affect performance, which is why this work requires proper knowledge and equipment.
7. Regulation and testing: Once assembled, the watch is adjusted and tested in different positions. Its rate, amplitude, beat error, winding performance and power reserve may be assessed, depending on the movement and available equipment.
8. Case and water-resistance checks: The case is cleaned appropriately, seals are renewed where needed and the watch is pressure-tested when its construction and condition allow. A pressure test is not a substitute for replacing visibly deteriorated seals or repairing a damaged case or crown.
9. Final inspection: The watch is checked for correct operation, secure assembly and any issues that could affect safe use. The work carried out and any recommendations should be recorded for future reference.

A service does not automatically mean that every external mark should be removed or that the case should be polished. On a preowned luxury watch, retaining original lines, edges and finishes can be important to its character and value. Any polishing, refinishing or replacement of visible parts should therefore be discussed beforehand, particularly where originality is a priority.

What is different about servicing a quartz watch?

Quartz watches typically require a battery replacement when the battery is depleted, together with inspection of the battery compartment and seals. A battery should not be left inside a watch after it has stopped, as leakage can damage the movement. During the replacement, the watch should be checked for corrosion, the case back and gasket should be refitted correctly, and water resistance should be tested if the watch is designed for it. A quartz movement may also need a broader service if it has suffered moisture ingress, contamination, impact or electronic failure.

Why a preowned watch may need more than a routine service

Preowned watches can have an incomplete history, replacement parts, previous repairs or wear that is not visible from the outside. A watch that has been stored for years may need attention even if it has seen little wrist time, while one worn daily may require earlier intervention. Vintage movements, chronographs, calendars and other complications often need additional expertise because they contain more components and may have specific adjustment and parts requirements.

Service work should be proportionate to the watch’s condition and your intended use. A diagnostic inspection may be suitable when the watch is running well and its history is documented. A complete service is more appropriate when lubrication has deteriorated, performance is outside acceptable limits or the movement’s condition cannot be established. If parts are required, you should be told what is recommended, whether the part is essential for reliable operation and whether the original component can be retained.

After servicing, avoid exposing the watch to unnecessary risks. Keep the crown fully closed, do not operate the crown or chronograph pushers in water, avoid strong magnetic fields and have the watch checked after a significant impact. Store it in a clean, dry place when it is not being worn, and keep the service documentation with its other ownership records. These simple measures help extend the period between services and support the watch’s future provenance.

If your preowned watch is losing or gaining time, stopping, showing condensation, making an unusual noise or has no dependable service history, arrange an assessment rather than waiting for the next routine interval. An expert inspection can establish whether it needs a full service, a specific repair, a battery and seal replacement, or simply a water-resistance and performance check.