Favoured by brands like Luminox and G-Shock, we look at why polymer is such a popular material for watch cases.
Some major watch manufacturers have based their entire collections, and reputation, on models that do not use metal in the primary construction of the case. In its place they use some form of polymer or resin material. When we think of “plastic" watches, more often than not the first style to pop into our minds would be a very basic digital watch, akin to the venerable Casio F-91W. This model epitomises the ultra-light resin watch, with such an iconic design that it has managed to transcend decades of style changes and still be as popular today as it was at its launch 33 years ago.
The obvious advantages to the construction of the F-91W and its counterparts is the lack of weight and low price. Moving up a notch, and beefing up the concept, you'll find a fleet of G-Shocks which follow the same principle but are much more capable. I have been wearing a blue G-9100 Gulfman (3088 module) for decades and the watch has never lost any of its original capability. At the risk of sounding like an advertising soundbite, it seems to be indestructible, and the only weakness the watch has presented through a tough life is a little colour fading. It has been bashed and knocked, dived underwater, boiled in 50-degree deserts, and subjected to 99% humidity. The ability to shrug off such harsh treatment typifies the strength of a well-designed, high quality, resin case.
But what about polymer on analogue watches? Such designs have traditionally been the domain of companies like Luminox. Such watches tend to have a military design background, and many are based on 1980s spec for standard issue Army watches. However, most are carbon based and not resin as you would find on a G-Shock.
Luminox's 2022 edition cases are made from a propriety material which they have branded CARBONOX+ (a successor to their first carbon creation). This is an ultra-lightweight composite which creates a rigid, graphite grey, hard finish. CARBONOX+ is a high-performance carbon long bar material, in which carbon fibres account for 40% of the compound. Its strength and durability properties are impressive and a standard 46mm case weighs in at six times lighter than steel and three times lighter than titanium. CARBONOX+ is also anti-allergenic, anti-magnetic and has superior chemical resistance. Unlike metal, carbon shell cases are not affected by heat and cold.
Whilst holding a dominant position, Luminox are not the only players in this market with Marathon using a fibre shell construction process for their milspec Navigator and General Purpose series watches.
The Navigator range challenges conventional design and symmetry with the entire right-hand side of the case projecting to cover the crown. The 41mm cases weigh an astonishing light 40g and are made from a proprietary composite fibre shell material which is light yet strong. Hence, Navigators are issued to numerous military units globally.Each case has a quick access hatch for battery change and is easily opened with a flat screwdriver. The trade-off is that Marathon offer limited water resistance with the Navigator, rated at 6ATM (60m). This is a non-industry standard measurement, but generally when such a number is quoted it is for a good reason, i.e., the case and lens have been tested to that limit.
To compliment the super rugged fibre shell case, Navigators are powered by an ETA F04 High Torque movement which offers good accuracy and a clever mechanism to not only power the hands but deal with shocks more efficiently than a standard quartz.
The Marathon General Purpose is very much the quintessential field or outdoor watch. Based heavily on military watches of old it displays several nods to historic US army watches. This range of watches is however thoroughly new while retaining a classic no nonsense look. Available with three movement choices, hand wound (ETA 2801), quartz (ETA F06), or automatic dual-wind (Seiko NH35), and in several case finishes, the GP is cleverly designed to appeal to a very wide demographic of buyer. Although all the variants are based ostensibly around the same watch, they can give a very different look.
A GP's Fibre shell cases, exactly as found on the Navigator, once again shed weight without any loss of strength. These ultra-light case are available in sage (green) or matt black and are shaped in a bold reassuring design, reminiscent of an ingot of material with highly distinct and blocky features. The stainless-steel variant GP has a smoother case design offering a more sophisticated look which aspires towards the high-end Field Watch category.
Water resistance for the General Purpose range is capped at 30m. This makes them unsuitable for intense water borne activity but for everyday needs it will be more than adequate.
Finally, Traser are worth a mention as they also deploy an equally comparable polyamide case manufacturing process best shown on their latest P96 ODP models. Traser outer cases are Glass-fibre reinforced resin with a steel inner case. At 61g these may be a little heavier than the Traser but in watch terms they are still exceptionally light. We reviewed the P96 in the WatchGecko magazine, but there is so little to pick between the Navigator, P96 or Navy SEAL it ultimately comes down to personal choice and whether deeper water resistance is critical.
The upshot of this type of watch construction is that you get a super durable and highly resistant product, probably 200m+ water resistance, which weighs little more than a small plastic digital watch. Were any of these watches in steel they would weigh well in excess of 100g but thanks to the use of highly innovative materials they are often half that.
There is no good reason not to own a polymer/carbon construction analogue watch. These materials are not prohibitively expensive to produce so consequent prices for the finished product are relatively low. Sub- £500 will secure many models from the principal manufacturers in this genre. Realistically, this type of case material will never replace steel or titanium as a primary ingredient. It is highly unlikely that you will see a Rolex Explorer in compressed carbon, although we note with interest this month's release of the Omega/Swatch Speedmaster “Moonswatch", so I guess anything is possible. Is there a place for a polymer outdoor watch in your collection? Absolutely, and once you get your head round the fact that extreme light weight does not translate to a lack of strength, you could be converted.