Revision of a mechanical Watch

05/2019: How much care does a mechanical watch need?

Mechanical watches are a marvel of technology; most of the components are filigree and very small. Apart from the time, they can represent the date and the lunar cycle mechanically, there are alarm clocks and chronographs – just to name a few complications.

To keep these marvels functioning as long as possible, regular maintenance is required, despite the use of modern materials and lubricants. Regular cleaning of the case and bracelet are one of those things that you can do by yourself. If the watch is rarely worn, it should be wound once a month so that the lubricants do not thicken or segregate. A watch winder for watches with automatic winding is not necessary; it is only of advantage for watches with calendar function, which might be tedious to adjust again. However, a regular oil change has to be made even if you use your watch carefully. It would be nice to simply fill the watches with oil, then drain and refill easily. But, it would hopelessly clog the delicate mechanisms. Depending on the load, various lubricants are used, which must be applied precisely to the respective spot and remain there through capillary action and adhesion. Influences like temperature, air, and even the smallest amounts of abrasion force us to replace these lubricants regularly. To be able to clean and oil each lubrication point, the watch and the movement must be disassembled completely during the so-called ‚Äúrevision”.

 

In the instructions manual supplied with your watch, you will find the recommended annual frequency in which an inspection should be carried out by the manufacturer or a suitable service workshop.

For our watches, we recommend a cycle between 4 and 7 years.

What happens with your watch during a revision? Which work steps does the watch have to go through in our company?

  1. Optical inspection and functional testing

The first step is an external evaluation and functional test of the watch. Notes are made, whether there are scratches on the case, how deep they are, and whether the watch is still water-resistant. A broken seal may have caused oxidation. In this case, increased cleaning effort is to be expected; in worst cases also the reworking or even replacement of parts. If this exceeds the scope of a simple revision, the customer will be consulted and estimated costs will be done.

  1. Disassemble of watch

In the next step, the watch will be dissembled. Each component is individually tested for wear. High temperatures, in particular, can cause the lubricant to run away unnoticed or dry out, leading to premature wear. Even then, parts have to be reworked or replaced. Each time parts are reconditioned or replaced, a function check is carried out. All components are sorted thematically on assembly trays and are then ready for cleaning.

  1. Cleaning of movement

In the third step, the watchmaker cleans all the components. The parts are cleaned using a rotary cleaning machine in an ultrasonic bath and various rinsing baths. The oils and fats are removed, and stubborn residues of dried fat and abrasion are also removed mechanically by the watchmaker beforehand. The parts are factory treated with a layer called Epilam. It increases the surface tension and ensures that the lubricants remain in their place. After several cleanings, this layer can lose its effect and must be renewed in a special bath.

  1. Refurbish of case

The watch case is cleaned or refurbished according to the customer’s requirements. Some of our customers just want the case to be cleaned; in their view, deep scratches on it symbolizes life and thus shouldn’t be altered. Other customers, on the other hand, would like the housing to be refurbished. Slight scratches are polished out. Deep scratches can be closed beforehand using laser welding. This allows the housing to be almost completely restored to its original condition. Here we respect the wishes of every single customer. This step takes place parallel to the cleaning of the movement parts.

  1. Assembly

Once cleaning is complete, the watch will be reassembled. During this process, a function check of the assembled parts is carried out again and again. All lubrication points are supplied with fresh oil and grease. Finally, the movement will be readjusted.

Once the movement is ready, it will be inserted into the case again. All seals are checked for wear (crown) and damage. Now the watch goes to quality control for several days. The accuracy of the watch will be tested with an automatic – 24h position test on the timer, which provides a diagram of the rate and amplitude of the balance in all positions and thus uncovers unwanted fluctuations. Then the watch comes on a circulating device, is wound up every day and read off. This gives us a picture of the watch accuracy as it is perceived by the customer. If further readjustments are not required, it is subjected to a water resistance test at 3 bar. Once the watch passes all tests, a final visual and functional check is carried out by two persons.

  1. Return shipment to the customer

Once all checks have been completed, the wristband, if it was delivered, is reassembled and the watch is ready for shipment. A repair certificate documents all work carried out and any replaced parts in a way that is comprehensible for the customer. The watch will be now sent to the owner together with the documentation and can be used again for many years.

Our credo is to carry out service work promptly so that the customer receives his watch back quickly. Please keep in mind: the more complications a watch has, the longer and therefore more expensive a revision can be.

Next time: …

previous article: More than a wrist watch

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