Dr. Ito's thorough analysis of mechanical watches!! Vol.40 - About the exterior finish of luxury watches

Good evening, everyone!

This column discusses mechanical watches from an engineer's perspective. For our 40th installment, we will be talking about:

"The Exterior Finishing of Luxury Watches"

I'll be discussing this topic.

Even if you handle your watch with care, scratches can accumulate without you noticing. Even if you're not aware of it, they can appear from a slight bump.

As long as you wear it on your wrist daily, some signs of wear are unavoidable. And sometimes, a watch with a few scuffs and a "worn" look can be more appealing than one that's perfectly pristine.

That being said, if it's too full of scratches, it can be bothersome, right?

So, this time, I'll explain the "finishing" process for luxury watches when they get scratched.

What is Exterior Polishing?

Scratches on luxury watches are typically removed by "polishing." Deep dents and dings cannot be completely removed, but they can be made less noticeable through surface polishing. This process, sometimes called "polishing," involves buffing with a specialized tool called a buffing motor.

Metal materials such as stainless steel and gold can have scratches removed by polishing. However, composite materials like carbon and ceramic, resin materials, or even metals that have undergone processes like PVD, cannot be polished.

By the way, we sometimes get inquiries about whether this polishing can be done "by oneself."

For this, I do not recommend polishing anything other than a plastic crystal. This is especially true for luxury watches.

The reason is that "it is extremely difficult to reproduce the finish of a new watch." I have seen many cases where the appearance was actually worsened instead of improved, so caution is advised.

The exterior parts of luxury watches are meticulously finished by the manufacturer, most commonly combining "mirror polishing" and "hairline finishing." These are done with specialized machinery, and each manufacturer has its unique techniques. If someone inexperienced attempts polishing, the grain of the finish can change or become distorted.

Also, in an attempt to remove a scratch from a mirror-polished surface, some people might accidentally polish the adjacent hairline finish, causing it to become shiny.

For these reasons, it is recommended to entrust the polishing of scratches on your watch to a specialist rather than attempting it yourself.

Is "Non-Polished" Best?

Have you ever heard the term "case thinning"?

Case thinning, as the name suggests, refers to the reduction in the case's surface area due to excessive polishing.

As mentioned at the beginning, exterior polishing is ultimately an act of "shaving." Of course, it's not literally shaving off large amounts, but rather a very fine polishing.

However, repeated polishing can lead to a reduction in the metal parts or rounding of the edges. This is what case thinning is.

Case thinning not only affects the appearance but also leads to reduced durability. When you send your watch for maintenance to the manufacturer, case replacement may sometimes be necessary. While scratches might be bothersome compared to a new product, it's important to know that overly frequent exterior polishing can lead to case thinning.

In recent years, with the trend of "non-polished examples being highly valued," many people believe that polished watches are less appealing. However, personally, I frankly prefer a watch expertly polished and beautifully finished by a skilled technician over a non-polished, heavily scratched one.

This depends on your perspective, but be careful not to be too fixated on "non-polished," as it might limit your options when purchasing a luxury watch.

What is Refurbishment?

As mentioned earlier, repeated polishing can lead to "case thinning," which can diminish the appeal and asset value of a luxury watch. Therefore, one finishing option to keep in mind is "refurbishment."

This term, meaning "restoration" or "renovation," refers to a method in luxury watch finishing where "deep scratches are repaired by welding, etc., and then the entire watch is finished to approximate a new condition."

This method eliminates the need to grind away surrounding areas to remove deep scratches, thereby minimizing case thinning. Since it requires high technical skill, it is only performed by some manufacturers and repair workshops, and the cost is high. If you've put a deep ding on your cherished watch, remember "refurbishment" as an option.

Summary

How was that?

For exterior polishing, not just for scratches but also to maintain the watch's original shape and finish, it's best to entrust it to a reliable professional. There are various options for who to commission, such as manufacturers or independent repair shops, so try to decide while considering your budget and the model you own. If you purchased the watch from a reputable dealer, consulting them about polishing and other maintenance might be the best approach.

I hope this article provided useful information for everyone and sparked even a little interest in luxury watches! Also, if you have any questions, please feel free to ask directly, and I will be happy to answer them thoroughly. We look forward to your visit and inquiries.

Stay tuned for the next installment! See you then!