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Watch Servicing

Overview

The frequency of watch servicing is influenced by the way the watch is used. A quality watch will last for generations with routine service.

The service process with PWR begins with a thorough examination of your watch. Our watchmaker examines the entire watch, evaluates its condition to advise you of the service recommendations. Estimates are provided normally with 48 hours.

Once authorised the hands and dial are removed. The movement is completely dismantled. Parts are separated into special cleaning baskets and ultrasonically cleaned. A specialist watch cleaning solution is used followed by rinsing solution. This procedure removes dry oil, congealed lubrications.

Before assembly parts are again inspected, when our watchmaker is satisfied that all components are in order. The watch movement is then assembled and lubricated meticulously by hand to the manufacturer's specifications. PWR only use the finest Swiss lubricants ensuring the minimum amount of friction and wear ensuring your watch performs for years to come. Time keeping of mechanical movements is completed in 6 positions. Replacement of gaskets and tested for water resistance.

Pricing

Premier Watch Repairs combine low overheads with a modern workshop enabling us to offer an efficient yet affordable service.

When you have a watch serviced by PWR. You are assured that there are no hidden costs.

The cost of service and repair varies depending on the type of movement, its functions and the condition of the watch. With this in mind, it is therefore only possible to provide estimates having first inspected a watch.

PWR can normally provide you with a free-of-charge estimate with no obligation, for your approval, normally within 48hrs after receiving your watch.

PWR fit only genuine factory parts fitted using specialist equipment recommended by the manufacturers. PWR adhere to recommendations of all watch brands and their quality control guide lines.

If during the repair or service process, further unforeseen work is required, this work will not be progressed until your approval has been sought.

All work is carried out on the premises and is covered by 12-month guarantee.

Premier Watch Repairs is dedicated to building a long-term relationship with all of our clients by providing a quality service at a competitive price.

To have an estimate provided for your watch please fill in the Online Form or call the workshop on 0845 4900 057

Guarantee

What does your guarantee include?

The guarantee covers the service of the watch movement and related parts fitted and listed for a period of 12 months from date of invoice.

Not covered under guarantee

Original watch movement parts or case parts not supplied by Premier Watch Repairs ,case and bracelet, dial, hands, crystal (glass), crown (button/winder), stem, electronic failure, moisture damage, rust, condensation, water penetration due to worn or damaged crown or pushers, general wear and tear, accidental damage, misuse or abuse.

If the fault is covered by this guarantee, repair will be commenced and upon completion, the watch will be returned to you. We reserve the right to refund original purchase price rather than repair. If the damage is a result of excluded causes, we will provide you with an estimate to complete the work or we may return your watch un-repaired.

No claims for repair work will be entertained from any third party repairers.

Case Restoration

You also have the option of case and bracelet restoration to restore the watch to its original appearance.

The Modern Tag Heuer watch case and bracelets used on models such as Carrera, Kirium, Link and Aquaracer are superbly made but can quickly attract scratches and scuffs through normal wear. After a few years the bracelet starts to look "worn".

Refinishing of the case and bracelet should only be carried out by the qualified watchmaker. The process involves the skilled use of polishing wheels, mops, brush wheels to achieve the required high quality finish.

Tools used range from miniature hard felts in mini drills right up to large power driven wheels for heavy material removal. PWR also use special machine mounted abrasives to achieve the correct contrasting brushed and highly polished finishes.

Where the case or bracelet has very heavy damage such as deep gouges, it won't be possible to restore the surface to the same high quality. This would require the removal of a significant amount of surface metal which would result in the loss of the original case and bracelet design. In these cases we have no alternative but to reduce the damage where possible before applying the new brushed or polished finish.

Before Restoration

After Restoration

Premier Watch Repairs offer a case and bracelet refurbishment service for Tag Heuer, Cartier, Zenith, Tissot etc.

Dial Restoration

PWR highly trained dial restorers are able to restore a wide variety of dials ranging from Tag Heuer, Breitling Rolex and many more.

The dial restorer can customize almost any aspect of a dial ranging from simply changing the colour of the dial to having a personal message or name inscribed into the dial.

Examples of Dial Restoration

Before Restoration

After Restoration

Please contact us for further information about restoring or customising your dial.

Chronometer Rating

COSC aka C.O.S.C. is Contrôle Officiel Suisse des Chronomètres, the Official Swiss Chronometer Testing Institute, which is the institute responsible for certifying the accuracy and precision of wristwatches in Switzerland.

Founded in its current form in 1973, the COSC is a Swiss non-profit organization that tests Swiss-made chronometers .COSC testing generally applies to watches manufactured /assembled in Switzerland.

Three laboratories now test the movements submitted by individual watch manufacturers to be granted chronometer status. They are in Biel/Bienne, Geneva and Le Locle. The Geneva and Biel laboratories are almost entirely devoted to testing Rolex movements. Although not all Rolex watches are chronometers, Breitling has claimed that since 2000 all of its production is COSC certified. Omega also has much of its production certified. Thus, based upon the movements used by Rolex, Breitling, and Omega, the movement calibers that obtain most of the COSC certificates are the Rolex 3135 (since 1988) (and variants 3155, 3175, 3185, 4130) and 2235, the ETA 2892A2 (and variants) and Valjoux 7750, each of which operates at 28,800 beats per hour.

Standards and methods

Each officially certified COSC chronometer is identified by a serial number engraved on its movement and a certification number given by the COSC.

Testing criteria are based on ISO 3159 which defines a wrist chronometer with spring-balance oscillator. Only movements which meet the precision criteria established under ISO 3159 are granted an official chronometer certificate. Compare ISO 3158.

Each uncased movement is individually tested for fifteen days, in five positions, at three different temperatures. The movements are fitted with a seconds hand and the automatic winding mechanisms are disengaged for the tests. Measurements are made daily with the aid of cameras. Based on these measurements, seven eliminatory criteria are calculated, each of which must be met e.g. for movements of a diameter over 20 mm, the requirements, indicated in seconds/day, are noted in the table below. There is no ISO standard for quartz timepieces, but there is development in this field. ISO 10553:2003 specifies the procedure for evaluating the accuracy of quartz watches, individually and by lot, and the relationship between the accuracy tested and the accuracy classification given by the manufacturer. It applies to quartz watches having accompanying documents on which the accuracy classification is indicated. Nevertheless, COSC has also developed its own standard for testing quartz chronometers with eight eliminatory criteria, also noted in the table below.

  • COSC Standards

    • Mechanical
    • Average daily rate: -4/+6
    • Mean variation in rates: 2
    • Greatest variation in rates: 5
    • Difference between rates in H & V positions:
    • -6/+8
    • Largest variation in rates: 10
    • Thermal variation: ± 0.6
    • Rate resumption: ± 5
    • n/a
    • Quartz
    • Average daily rate at 23 °C: ± 0.07
    • Rate at 8 °C: ± 0.2
    • Rate at 38 °C: ± 0.2
    • Rate stability: 0.05
    • Dynamic rate: ± 0.05
    • Temporary effect of mechanical shocks: ± 0.05
    • Rate resumption: ± 0.05
    • Residual effect of mechanical shocks: ± 0.05;

      200 shocks equivalent to 100 G (981 m/s2, 3,217 ft/s2)

Measurements are compared with a time base established by two independent atomic clocks synchronized on GPS time. Not all chronometers are supplied with the report issued by the COSC as the reports are optional to the brand or maker. Each manufacturer may decide whether to reveal the results gathered during the certification process of the movement. For example, Breitling do supply all their watches with COSC Certificates (all Breitling watches since 2000 are Certified chronometers) however Rolex and Omega do not supply even their chronometer certified watches (not all their watches are certified chronometers) with the COSC certificates. Omega however can provide the COSC chronometer certificate if asked.

Observatory trials and standards before 1973

While competitive chronometer testing took place at the observatories in Neuchâtel (1866-1975) and Geneva (1873-1967), testing of large numbers of watches intended for public sale was conducted by the independent Bureaux officiels de contrôle de la marche des montres (B.O.s) established between 1877 and 1956. Between 1961 and 1973, "a chronometer [was] a precision watch, which [was] regulated in several positions and at different temperatures and which had received a certificate [from the ("B.O.)]." Collective certificates, rather than individual certificates, were usually issued. The 1961-73 standard required a mean daily rate in five positions of -1/+10. In 1973, the B.O.'s came under the C.O.S.C. which specified a daily rate of -4/+6 sec.

Meaningful test or marketing gimmick?

There is a debate among watch enthusiasts as to whether the COSC chronometer certification for a Swiss watch is a meaningful test or a simple marketing gimmick. On the one hand, when a watch maker intends to submit a movement for COSC testing, they frequently employ additional jewelling (i.e. to the barrel) and better quality" Ébauche " parts (i.e. higher quality hairsprings, mainsprings, balance wheels; regulators, etc.) all aimed at the coveted chronometer certification. On the other hand, it is likely that most good quality movements on the market today are capable of being tweaked, and timed to fall comfortably within the benchmark -4/+6 average daily rate criteria of the COSC. However, movements so submitted to COSC are more likely to be submitted with better quality parts in order to be confident of a successful test, and as a consequence may be more likely to maintain better timekeeping rates over the service life of the time piece.

Brands submitting to COSC

Rolex submit by far the largest number of movements to COSC followed by Omega SA, Breitling, TAG Heuer and Panerai. Breitling submit all movements for certification but other manufacturers only submit certain models.

Certification in perspective

Fine regulation and chronometer characteristics of a watch can be destroyed in seconds by a rough and inexperienced hand. Considering the fact that mechanical watches are almost never used for real timekeeping and navigation anymore, and that practically any quartz watch is vastly better in accuracy, certification may be considered a historic relic by some, but it verifies the accuracy and quality of a mechanical movement. Quartz movement is almost always more accurate however mechanical movements are preferred by some watch enthusiasts.

Water resistance classification

Watches are classified by their degree of water resistance which, due to the absence of official classification standards, roughly translates to the following (1 metre ≈ 3.29 feet):

    • Water resistance rating
    • Water Resistant or 30 m
    • Water Resistant 50 m
    • Water Resistant 100 m
    • Water Resistant 200 m
    • Diver's 100 m
    • Diver's 200 m or 300 m
    • Diver's 300+ m for mixed-gas diving
    • Suitability
    • Suitable for everyday use. Splash/rain resistant. NOT suitable for swimming, snorkelling, water related work and fishing.
    • Suitable for surface swimming, non-snorkelling water related work, and fishing.
    • Suitable for recreational surfing, swimming, snorkelling, sailing and water sports.
    • Suitable for professional marine activity and serious surface water sports.
    • Minimum ISO standard (ISO 6425) for scuba diving at depths NOT suitable for saturation diving.
    • Suitable for scuba diving at depths NOT suitable for saturation diving.
    • Suitable for saturation diving (helium enriched environment).
    • Remarks
    • NOT suitable for diving.
    • NOT suitable for diving.
    • NOT suitable for diving.
    • NOT suitable for diving.
    • Diver's 100 m and 150 m watches are generally old(er) watches.
    • Typical ratings for contemporary diver's watches.
    • Watches designed for mixed-gas diving will have the DIVER'S WATCH L M FOR MIXED-GAS DIVING additional

Water Resistant mark

Water Resistant is a common mark stamped on the back of wrist watches to indicate how well a watch is sealed against ingress of water. It is usually accompanied by an indication of the static test pressure that a sample of newly manufactured watches was exposed to in a leakage test. The test pressure can be indicated either directly in bars, atmospheres, or (more commonly) as an equivalent water depth in metres (in the United States sometimes also in feet).

An indication of the test pressure in terms of water depth does not mean a water resistant watch was designed for repeated long term use in such water depths. For example, a water resistant watch marked at 30 metres depth cannot be expected to withstand activity such as swimming, let alone continue to function at 30 metres under water. This is because the test is conducted only once using static pressure on some of the newly manufactured watches. The test for qualifying a diving watch for repeated usage in a given depth includes safety margins to take factors into account like ageing of the seals, rapidly changing water pressure and temperature, as well as dynamic mechanical stresses encountered by a watch. Also every diving watch has to be fully tested for water resistance.

ISO 2281 water-resistant watches standard

The International Organization for Standardization issued a standard for water resistant watches which also prohibits the term waterproof to be used with watches, which many countries have adopted. The international standard ISO 2281 Horology - Water-resistant watches defines the water resistance of watches. This standard was only designed for watches intended for ordinary daily use and are resistant to water during exercises such as swimming for a short period. They may be used under conditions where water pressure and temperature vary. However, whether they bear an additional indication of overpressure or not, they are not intended for submarine diving.

The ISO 2281 standard specifies a detailed testing procedure for each mark that defines not only pressures but also test duration, water temperature, and other parameters.

ISO 2281 water resistance testing of a watch consists of:

•   Resistance when immersed in water at a depth of 10 cm. Immersion of the watch in 10 cm of water for 1 hour.

•   Resistance of operative parts. Immersion of the watch in 10 cm of water with a force of 5 N perpendicular to the crown and pusher buttons (if any) for 10 minutes.

•   Condensation test. The watch shall be placed on a heated plate at a temperature between 40 °C and 45 °C until the watch has reached the temperature of the heated plate (in practice, a heating time of 10 minutes to 20 minutes, depending on the type of watch, will be sufficient). A drop of water, at a temperature of 18 °C to 25 °C shall be placed on the glass of the watch. After about 1 minute, the glass shall be wiped with a dry rag. Any watch which has condensation on the interior surface of the glass shall be eliminated.

•   Resistance to different temperatures. Immersion of the watch in 10 cm of water at the following temperatures for 5 minutes each, 40 °C, 20 °C and 40 °C again, with the transition between temperatures not to exceed 1 minute. No evidence of water intrusion or condensation is allowed.

•   Resistance to water overpressure. Immersion of the watch in a suitable pressure vessel and subjecting it within 1 minute to the rated pressure for 10 minutes, or to 2 bar in case where no additional indication is given. Then the overpressure is reduced to the ambient pressure within 1 minute. No evidence of water intrusion or condensation is allowed.

•   Resistance to air overpressure. Exposing the watch to an overpressure of 2 bar. The watch shall show no air-flow exceeding 50 μg/min.

•   No magnetic or shock resistance properties are required.

•   No negative pressure test is required.

•   No strap attachment test is required.

•   No corrosion test is required.

Except the thermal shock resistance test all further ISO 2281 testing should be conducted at 18 °C to 25 °C temperature. Regarding pressure ISO 2281 defines: 1 bar = 105 Pa = 105 N/m2.

In practice, the survivability of the watch will depend not only on the water depth, but also on the age of the sealing material, past damage, temperature, and additional mechanical stresses.

None of the tests defined by ISO 2281 are suitable to qualify a watch as a diving watch. ISO 2281 compliant watches are designed for everyday life and must be water resistant during exercises such as swimming for a short period. They can be worn in different temperature and pressure conditions but are under no circumstances designed for diving with underwater breathing apparatus.

ISO 6425 divers' watches standard

The standards and features for diving watches are regulated by the ISO 6425 - Divers' watches international standard. ISO 6425 defines such watches as: A watch designed to withstand diving in water at depths of at least 100 m and possessing a system to control the time. Diving watches are tested in static or still water under 125% of the rated (water)pressure, thus a watch with a 200 metre rating will be water resistant if it is stationary and under 250 metres of static water. The testing of the water resistance is fundamentally different from non-dive watches, because every watch has to be fully tested.

ISO 6425 water resistance testing of a diver's watch consists of:

•   Reliability under water. The watches under test shall be immersed in water to a depth of 30 cm ± 2 cm for 50 hours at 18 °C to 25 °C and all the mechanisms shall still function correctly. The condensation test shall be carried out before and after this test to ensure that the result is related to the above test.

•   Condensation test. The watch shall be placed on a heated plate at a temperature between 40 °C and 45 °C until the watch has reached the temperature of the heated plate (in practice, a heating time of 10 minutes to 20 minutes, depending on the type of watch, will be sufficient). A drop of water, at a temperature of 18 °C to 25 °C shall be placed on the glass of the watch. After about 1 minute, the glass shall be wiped with a dry rag. Any watch which has condensation on the interior surface of the glass shall be eliminated.

•   Resistance of crowns and other setting devices to an external force. The watches under test shall be subjected to an overpressure in water of 125% of the rated pressure/10 bar for 10 minutes and to an external force of 5 N perpendicular to the crown and pusher buttons (if any). The condensation test shall be carried out before and after this test to ensure that the result is related to the above test.

•   Water-tightness and resistance at a water overpressure. The watches under test shall be immersed in water contained in a suitable vessel. Then an overpressure of 125% of the rated pressure shall be applied within 1 minute and maintained for 2 hours. Subsequently the overpressure shall be reduced to 0.3 bar within 1 minute and maintained at this pressure for 1 hour. The watches shall then be removed from the water and dried with a rag. No evidence of water intrusion or condensation is allowed.

•   Resistance to thermal shock. Immersion of the watch in 30 cm ± 2 cm of water at the following temperatures for 10 minutes each, 40 °C, 5 °C and 40 °C again. The time of transition from one immersion to the other shall not exceed 1 min. No evidence of water intrusion or condensation is allowed.

•   An optional test originating from the ISO 2281 tests (but not required for obtaining ISO 6425 approval) is exposing the watch to an overpressure of 2 bar. The watch shall show no air-flow exceeding 50 μg/min.

Except the thermal shock resistance test all further ISO 6425 testing should be conducted at 18 °C to 25 °C temperature. Regarding pressure ISO 6425 defines: 1 bar = 105 Pa = 105 N/m2. The required 125% test pressure provides a safety margin against dynamic pressure increase events, water density variations (seawater is 2 to 5% denser than freshwater) and degradation of the seals.

Movement induced dynamic pressure increase is sometimes the subject of urban myths and marketing arguments for diver's watches with high water resistance ratings. When a diver makes a fast swimming movement of 10 m/s (32.8 ft/s) (the best competitive swimmers and fin-swimmers do not move their hands nor swim that fast) physics dictates that the diver generates a dynamic pressure of 0.5 bar or the equivalent of 5 meters of additional water depth.

Besides water resistance standards to a minimum of 100 metres (330 ft) depth rating ISO 6425 also provides minimum requirements for mechanical diver's watches (quartz and digital watches have slightly differing readability requirements) such as:

The presence of a time-preselecting device, for example a unidirectional rotating bezel or a digital display. Such a device shall be protected against inadvertent rotation or wrong manipulation. If it is a rotating bezel, it shall have a minute scale going up to 60 min. The markings indicating every 5 min shall be clearly indicated. The markings on the dial, if existing, shall be coordinated with those of the preselecting device and shall be clearly visible. If the preselecting device is a digital display, it shall be clearly visible.

•   The following items of the watch shall be legible at a distance of 25 cm (9.8 in) in the dark:

   ο time (the minute hand shall be clearly distinguishable from the hour hand);

   ο set time of the time-preselecting device;

   ο indication that the watch is running (This is usually indicated by a running second hand with a luminous tip or tail.);

   ο in the case of battery-powered watches, a battery end-of-life indication.

•   The presence of an indication that the watch is running in total darkness. This is usually indicated by a running second hand with a luminous tip or tail.

•   Magnetic resistance. This is tested by 3 expositions to a direct current magnetic field of 4,800 A/m. The watch must keep its accuracy to +/- 30 seconds/day as measured before the test despite the magnetic field.

•   Shock resistance. This is tested by two shocks (one on the 9 o'clock side, and one to the crystal and perpendicular to the face). The shock is usually delivered by a hard plastic hammer mounted as a pendulum, so as to deliver a measured amount of energy, specifically, a 3 kg hammer with an impact velocity of 4.43 m/s. The change in rate allowed is +/- 60 seconds/day.

•   Resistance to salty water. The watches under test shall be put in a 30 g/l NaCl (sodium chloride) solution and kept there for 24 hours at 18 °C to 25 °C. This test water solution has salinity comparable to normal seawater. After this test, the case and accessories shall be examined for any possible changes. Moving parts, particularly the rotating bezel, shall be checked for correct functioning.

•   Resistance of attachments to an external force (strap/band solidity). This is tested by applying a force of 200 N (45 lbf) to each springbar (or attaching point) in opposite directions with no damage to the watch of attachment point. The bracelet of the watch being tested shall be closed.

•   Marking. Watches conforming to ISO 6425 are marked with the word DIVER'S WATCH L M or DIVER'S L M to distinguish diving watches from look a like watches that are not suitable for actual scuba diving. The letter L indicates the diving depth, in metres, guaranteed by the manufacturer.

Diver's watches for mixed-gas diving

Diving at a great depth and for a long period is done in a diving chamber, with the diver spending time alternately in the water and in a pressurized environment, breathing a gas mixture. In this case, the watch is subjected to the pressure of the gas mixture and its functioning can be disturbed. Consequently, it is recommended to subject the watch to a special extra test. ISO 6425 defines a diver's watch for mixed-gas diving as: A watch required to be resistant during diving in water to a depth of at least 100 m and to be unaffected by the overpressure of the mixed gas used for breathing.

The following specific additional requirements for testing of diver's watches for mixed-gas diving are provided by ISO 6425:

•   Test of operation at a gas overpressure. The watch is subject to the overpressure of gas which will actually be used, i.e. 125% of the rated pressure, for 15 days. Then a rapid reduction in pressure to the atmospheric pressure shall be carried out in a time not exceeding 3 minutes. After this test, the watch shall function correctly. An electronic watch shall function normally during and after the test. A mechanical watch shall function normally after the test (the power reserve normally being less than 15 days).

   Test by internal pressure (simulation of decompression). Remove the crown together with the winding and/or setting stem. In its place, fit a crown of the same type with a hole. Through this hole, introduce the gas mixture which will actually be used and create an overpressure of the rated pressure/20 bar in the watch for a period of 10 hours. Then carry out the test at the rated water overpressure. In this case, the original crown with the stem shall be refitted beforehand. After this test, the watch shall function correctly.

   Marking. Watches used for mix-gas diving which satisfy the test requirements are marked with the words "DIVER'S WATCH L M FOR MIXED-GAS DIVING". The letter L indicates the diving depth, in metres, guaranteed by the manufacturer. The composition of the gas mixture used for the test shall be given in the operating instructions accompanying the watch.

Most manufacturers recommend divers to have their diving watch pressure tested by an authorized service and repair facility annually if used regularly in water.