Bronze watches can be seen as an interesting and niche segment of various watch categories, if you’d like. While not new, bronze casing for watches has gained renewed vigour in recent years as mainstream luxury brands, such as Panerai, IWC and Tudor, are embracing the material with open arms.

The spotlight of this piece is on patina development in bronze watches. We cast our eyes on bronze watches with a focus on providing insight to how oxidation affects the look of your bronze watch cosmetically. We will showcase the patina development on a watch that has been worn and one that has purely been on display (i.e., with minimal human contact except for regular maintenance/checks). Before that, let’s find out a little bit more about bronze. 

What’s special about bronze?

Bronze is essentially an alloy of copper, tin and other metals (aluminum, zinc or nickel) in tiny quantities. A unique characteristic of bronze is that it develops a layer of patina, which results in colour changes. The development of patina is a natural process in all types of bronze. The patina itself is the result of copper oxidizing from exposure to air, and is usually a combination of copper chlorides, sulfides, and carbonates.

Bronze Panels [Photograph by Tim Evans/Unsplash.com]

Bronze Panels [Photograph by Tim Evans/Unsplash.com]

There are various grades of bronze used for watchcases. The grade most widely used is marine-grade bronze, commonly known as CuSn8 bronze; aluminum bronze or other variants of marine grade bronze, such as CuSn12 bronze, tend to be uncommon as it has a lower hardness compared to CuSn8. CuSn8, an alloy of copper and tin, is long regarded as the industry standard for its evergreen usage in nautical applications because of its high resistance to corrosion. Hence, CuSn8 is more commonly used in watchcases. Aluminum bronze on the other hand uses aluminum in place of tin. It is similar to CuSn8 bronze in terms of strength and resistance to corrosion. An example of a watch that uses aluminum bronze is the Tudor Heritage Black Bay Bronze.

Ship Anchor [Photograph by Woodrow Walden/Unsplash.com]

Ship Anchor [Photograph by Woodrow Walden/Unsplash.com]

At Red Army Watches, some of the bronze watches we have, which are featured here, include the Heroic 18 M9100 and the Vostok Europe Almaz Bronze. Not only do both watches use CuSn8 bronze cases, they are both well-made pieces in their own right. Let’s dive in for a closer look at the watches.

Showcase: Heroic18 M9100

Heroic18 M9100

Heroic18 M9100

Heroic18 is a micro-brand that pays homage to vintage-inspired dive tool watches. The company prides itself for its workmanship and the attention it pays to minor details. The Heroic M9100 is a special edition piece cased in CuSn8 bronze and features a textured green gradient dial.

Despite looking a little daunting initially, the watch was anything but. My time spent with the watch was pleasant and filled with surprises. The construction and execution of the watch showed that much thought process was put in when the watch was conceptualised. Operation of the signed crown was buttery smooth (literally). The screwed-on crown guards were attached flawlessly; I couldn’t tell they were two different components until I saw the screws along the side. 

The case of the M9100 is polished and finely brushed-finished throughout. At the time of writing, the watch was given a round of polishing roughly two weeks before. A new set of patina is just about to develop and we’ll have a closer look at how the patina develops along the polished and brushed surfaces of the case. At this point, it is worth highlighting that the owner of the watch did not wear his M9100 on a daily basis.

Crown and crown guards with a more distinct set of patina

Crown and crown guards with a more distinct set of patina

Patches of patina seen on the M9100

Patches of patina seen on the M9100

M9100 lugs with bluish streaks M9100 lugs with bluish streaks

From the images above, you will notice patches of patina starting to develop along the case and on the bezel. Perhaps these patches had more contact with the owner’s hand, which caused a slightly faster pace of oxidation. The lustre and warmth of the bronze remain noticeable. Also, the watch crown is seen to patina faster as it comes into contact with the fingers quite frequently as a result of winding and date/time adjustment.

Showcase: Vostok Europe Almaz Bronze

Vostok Europe Almaz

Vostok Europe Almaz

The Almaz Bronze is Vostok Europe’s first watch in bronze. The Almaz may seem unassuming at first glance; but in terms of design, it is well conceptualised and executed. The hands and raised indices of the Almaz are lined with rose gold plating, giving some semblance to the original lustre of the bronze case. I like how the background of the date wheel is coloured black; even though this is a minor detail, I believe it will bring more smiles than frowns to owners of the watch. For me, the bezel of the Almaz stands out. The minute markers and hashes are relief engraved. The knurls lining the side of the bezel resemble little diamond facets, combining mirror and brushed polishes.

The BaselWorld 2015 novelty is generally brush finished throughout. It is worth pointing out that the copper content in the Almaz is slightly higher; therefore, it has a warmer shade of red compared to the Heroic18.

Patina on the crown of the Almaz

Patina on the crown of the Almaz

Bezel knurls

Bezel knurls

Patina developing on the bezel knurls

Patina developing on the bezel knurls

Looking at the images of the watch, it can be seen that the patina is more uniform on the Almaz as it rarely came into human contact. The patina is reddish brown, almost a dull maroon-like colour that complements the matte look of the Almaz. Again, the watch crown can be seen to exhibit a faster rate of patina for the same reason mentioned about the Heroic18.

Bronze watches are definitely an interesting choice of case material to own. You get to witness the evolution of your watch as it starts to develop patina over time. It truly is a unique piece, as no two bronze watches will resemble each other.

Heroic18 M9100 is sold out but other bronze Heroic18 models are available at Red Army Watches (Millenia Walk, Wisma Atria) and Krasnaya (ION Orchard). Vostok Europe Bronze Almaz Green is available on our e-store and at all our stores.