In this article, Yutaro Iizuka, a watchmaker at Chrono Theory Tokyo, a watch shop in Ginza, writes about the importance of watch repair and maintenance through his own work. He explains that in many cases, problems cannot be identified without disassembly, and even if there are no actual problems, it is important to proceed with the work while identifying factors that may cause problems in the future.
Article published on June 2023, 4
A watchmaker explains maintenance
I, a Chronotheory watchmaker, have been asked to write about maintenance. I am extremely honored to have been given this opportunity.
I had never had the experience of talking to customers face-to-face before, but after coming to ChronoTheory and talking to them, I got the following impression: There are more people than I imagined who have questions about maintenance but don't have the opportunity to talk to the technician in charge, and are therefore unable to ask.
So, I would like to write about maintenance work through actual work, and also about the ingenuity and hardships of the technicians, in the hope that it will help deepen your understanding of maintenance.
Maintenance of Jörg Schauer Edition 9 "The Baton from Mr. Schauer"
The watch we received this time was Jörg Schauer's "Edition 9." The movement it was equipped with was the general-purpose caliber ETA7750, but the finishing details were a model with Schauer's unique beauty.
The machine appeared to be in good condition with only oil deterioration, so we took it in for regular maintenance, but of course it wasn't something that could be done by simply washing and reassembling it; there were problems that would require the replacement of major parts in the future.
Deterioration of oil is the beginning of problems
Oil deteriorates over time, but the degree and condition varies depending on the age and frequency of use. If oil is used frequently and for a long time, it can become viscous, like the grease stains on a kitchen stove, or dry out.
Continuing to use the watch in this condition will not only cause wear on the gear shafts but will also lead to malfunctions in the entire watch, so removing this dirt is an important part of maintenance. It is not enough to simply wash it in an ultrasonic cleaner and reassemble it.
It is necessary to determine the condition of the oil and then use a wooden stick as shown in the photo to scrub away the deteriorated oil from the gear shaft holes. This kind of mundane effort and time-consuming work is extremely important.
Schauer's philosophy is reflected in the movement's finishing
The plates of the ETA7750 caliber are usually silver, but by making them gold, the movement has a more luxurious feel.
In addition, Schauer also puts a lot of effort into the screws. The screw heads (the parts with the slits) of the original Caliber ETA7750 are flat, but not mirror-finished. They are all finished in different ways depending on the location: black polish (mirror finish), satin, or matte (sandblasted). This also conveys Schauer's aesthetic.
I was grateful to receive a request to maintain a watch that embodies his soul, and at the same time, I felt a sense of responsibility as a watchmaker to continue to convey the maker's thoughts to customers.
It's just a screw, but it's still a screw!
There is one area where my personal focus and Mr. Schauer's aesthetic overlap: screws.
Basically, screws tend to strip (or "screw") when opened and closed with a screwdriver. It is natural for a watchmaker to minimize this, but repeated overhauls inevitably result in "screws." It is unavoidable.
However, that doesn't mean we should just leave it alone, and we need technicians who can fix it. That's why Chrono Theory includes screw refinishing in our maintenance fees. We also share the overhaul process with our customers at the time of delivery (as we do at Chrono Theory), which makes them happy, so I'm happy to do the work myself.
This watch was no exception, and the screws, which are packed with Schauer aesthetics, had scratches and dents, so they were refinished. Since it is not possible to introduce all the screws that were refinished, I would like to introduce the method for refinishing the matte screws, which was relatively difficult.
It's hard to see in the photo, but you can see a slightly different way light reflects near the slit. This is when the screw is "smiling." First, remove that, then apply oil mixed with white alundum to the sapphire crystal, and rub it with tweezers to create a matte finish.
The skills and training required for repair and maintenance
Occasionally, screws inside the movement, screws that secure the movement to the case, screws on the case back, etc. break. There are various reasons why screws break, but whatever the reason, removing broken screws is a skill that watchmakers should master, even if they would rather not do it.
The cost of removing broken screws is rarely included in the maintenance fee unless it is known at the time of quotation. The current situation is that the more experienced the watchmaker, the easier and quicker the job is to perform, and it is difficult to explain the cause of a broken screw, so it is not reflected in the price.
This is a skill that can be acquired by thinking a lot, trying things out, making tools, and repeating this process until you reach a certain level, so we ask that customers understand when labor charges are requested.
This time, when I was disassembling the part, I tried to remove the screw but it broke just by turning it lightly. Screws can break if they are tightened too much, but this is the first time it has broken (when removing it). There's no point in thinking about the cause, so I came up with a plan, prepared everything, and started working on it. In the end, I was able to remove it cleanly, but it wasn't a matter of just replacing it; I had to make a finished screw.
