With many of us here in the States starting to prepare and decorate for a (socially-distanced) Fourth of July celebration, it seemed an appropriate time to shine a light on Rolex’s modern red and blue marvel: the Cerachrom red and blue bezel.
The Pepsi GMT, properly called the Bleu/Rouge (BLRO), first launched in 1954 to help long-haul Pan Am pilots manage multiple timezones. The now-iconic red and blue color scheme was developed to quickly show daylight hours (red) vs. nighttime hours (blue).
Except for an early initial run of Bakelite, these bezels were made of aluminum with the various color palettes applied onto the aluminum. Unlike the GMT Masters themselves, which can see decades of faithful service, the aluminum bezels were known to fade and scratch over time. Despite the panoply of multi-thousand-dollar faded bezel inserts on the secondary market, Rolex was unhappy with the continued use of legacy manufacturing processes and sought better options.
Photo credit @coldcasewatches
It was 2005 when the first Cerachrom-bezeled Rolex hit the market. The black ceramic GMT-Master II produced in 18kt yellow was the first and only ceramic rolex made that year. Subsequent to that release, several additional single-color bezels would follow including blue and green.
Cerachrom is the name for Rolex’s proprietary ceramic material, and it has proven to be an improvement over aluminum in many ways. The extreme hardness of Cerachrom makes it nearly impervious to scratches. Just as with an Everest rubber strap for Rolex, the Cerachrom is impervious to UV fading and a wide array of hard chemicals.
The manufacture of Cerachrom actually starts with green ceramic powder. This powder is mixed with a binding agent, heated, and then high-pressure injected into a mold to provide shape and numerals to the bezels.
After forming the initial shape, a second round of heat is used to remove the binding agents. This process (known as de-binding) leaves the ceramic absorbent and ready for color. The green parts are then submerged into a water-based solution which drives the final color.
Following that, a 1,600 degree celsius firing process fully-forms the ceramic (and its color) into the final hard bezel. This molecular bonding process is known as sintering. During the heat of sintering, the part itself can shrink between 25 and 30 percent.
Armed with an understanding of this process, it’s no wonder that a two-tone bezel would be so difficult to produce. Despite what one might think, the BLRO bezel of the ceramic Pepsi is actually a single-piece.
In 2014, Rolex finally unveiled to the world a single-piece two-tone ceramic bezel. As is commonly done, the first BLRO launched was only offered in white gold.
There’s a secret behind these dual-color pieces of ceramic, however. The initial production of a BLRO bezel is actually fully-red ceramic - a color once thought impossible in ceramic. Through compounds including alumina, magnesium oxide, and chromium oxide, a striking red bezel is produced. In fact, alumina is a key ingredient in the production of synthetic rubies.
Once a red bezel has been produced, half of the part is coated in a proprietary chemical mixture and then the part is again heated. It is the chemical reaction of this proprietary process that turns the top of the bezel blue.
An Everest Bands customer using a blacklight to reveal the red bezel on his BLRO prior to installing a red Everest Bands deployant strap.
The final step is to fill the numerals and other bezel elements with platinum or gold. To achieve such a flawless finish inside of the numerals, the entire part is actually coated using a process known as Physical Vapour Deposition (PVD). In the Rolex PVD process, precious metals are vapourized and then applied to the part, generally while held under vacuum.
With the entire part coated, all that remains is to polish off most of the PVD covering the bezel, revealing the beautiful two-tone color beneath.
While the finished product of a BLRO is an aesthetic wonder, it’s also the culmination of many proprietary steps. And should you want to brighten up your BLRO with even more red or blue, Everest Bands offers many colors of straps to complete your look which we explore here.