In the early 2000s, Rolex set up its own state-of-the-art foundry where it casts its gold. This unusual step for a watchmaking brand allows Rolex to ensure that only the ﬁnest of this precious metal is used in its luxury timepieces.
The exclusive 18 ct yellow, white and Everose gold alloys are cast by experienced foundrymen according to carefully guarded formulas, producing impeccable, noble metals that are as treasured for their radiance today as gold was in antiquity.
Bent over a crucible ringed with flames, protected from the heat by a heavy thermal suit, thick elbow-high gloves and a helmet whose visor reflects the blinding glow of molten gold, the foundryman’s cumbersome garb belies the finesse of his work. Strength, a careful hand and subtlety are needed in equal measure to pour the valuable liquid alloy through a sieve, creating droplets which, as they fall into a vat of water, are instantly cooled to become small beads of 18 ct gold.
At this moment, the foundryman is doing more than giving life to a sumptuous metal. He is ensuring the nobility of the raw material, which, many operations later, will form exceptional Rolex watches. The foundryman at Rolex is the first link in the chain that produces the middle cases, case backs, bezels and bracelet components of these luxurious gold timepieces.
In its pure, 24 ct state, gold is too malleable for everyday use on a wristwatch. To make it harder and improve its resistance, it must be alloyed with other metals, creating 18 ct gold. This princely alloy, composed of 750‰ (thousandths) of pure gold, is prized by watchmakers. Different types of 18 ct gold – yellow, white or pink – are obtained by adding a certain proportion of silver, copper, platinum or palladium.
The quality and properties of gold alloys can vary, depending on the rigour of the alloying process. For this very reason, Rolex developed its own foundry in the early 2000s, thereby mastering every manufacturing detail and ensuring that only the highest quality gold alloys find their way into its watches.
On the workbench of the foundry, carefully packaged and labelled metals are waiting to be mixed with each other: brilliant yellow pure-gold beads, grey-white silver bars, pink-red copper billets, and, depending on the desired alloy, platinum or palladium.
Meticulously, the foundryman pours the metals into a graphite crucible in a prescribed order, and in precise quantities measured to within one-tenth of a gram. The quality of the resulting yellow, white or Everose gold and its fineness (the percentage of pure gold that it contains) depend on his deft touch and strict respect for the proper proportions.
For the first fusion, in the crucible, the metals are brought to a temperature of 1,150 °C or more, uniting in an incandescent liquid. When the foundryman carefully passes the contents of the crucible through the sieve, a blowtorch spits flames on the flowing gold to protect it from the ambient oxygen, and therefore from oxidation.
The liquid falls in droplets into a vat of water thus forming small beads as the gold cools instantly and solidifies amid clouds of steam. The 18 ct gold is born. When the foundry man raises his visor, it is difficult not to notice his gentle smile, a quiet, outward manifestation of satisfaction with a first job well done. Yet, his work is far from over.
Once the beads are dried, they are scrupulously inspected by the experienced foundryman for potential flaws. Samples are also taken to verify the composition and fineness, while the rest is stored until the go-ahead is given for the second fusion, the continuous casting.
This machine process is less spectacular, but no less critical than the first fusion. Under the control of the foundryman, the gold beads are placed in the furnace of the continuous casting machine. Once melted, the gold is cast through a water-cooled die, in which it solidifies, producing the required shape: slabs for the middle cases and case backs, bars for the bracelet links, or rods for the bezels.
Although the two hours of continuous casting are carried out by machine, the skill and know-how of the foundryman are still crucial. He makes sure that the gold solidifies at the correct rate – necessary for the proper structure of the metal – and he watches that the dies are rigorously aligned to obtain the perfectly straight casting needed to optimize the subsequent forming operations. The machine tools, gold bath and cooling water all need to be at specific temperatures in order to guarantee the final quality of the solid gold. One single mistake during the operation and the entire 18 ct gold casting would be ruined. While they are still hot, the castings are inspected and sent for quality analysis. Afterwards the metal-forming workshops will take over the newly created 18 ct gold and shape it with the same sense of perfection and care.
The foundryman’s highly specialized task has come to an end, after drawing on a magical combination of the four fundamental elements of ancient philosophy and astrology: fire, air, water and, from the earth, one of the most precious metals: gold.