The aging of the sealing ring is one of the main reasons for the decline in the waterproof performance of a watch. The mechanism and specific manifestations of this issue can be analyzed in depth through the following aspects:
I. Core manifestations of aging of the sealing ring and its impact on water resistance
Material hardening and loss of elasticity
Symptom: The rubber sealing ring gradually hardens and becomes brittle due to long-term oxidation or ultraviolet radiation, losing its elasticity.
Impact: The sealing ring is unable to fill the tiny gaps between the case and components, resulting in water infiltration. For example, a sealing ring that could be compressed by 20% before aging can only be compressed by 10% after aging, causing the sealing gap to increase and significantly increasing the risk of water resistance failure.
Cracks and fractures
Symptom: Fine cracks appear on the surface of the sealing ring, and in extreme cases, it may completely fracture.
Impact: Cracks become direct channels for water infiltration. For example, in a 50-meter water-resistant watch, a 0.1mm crack in the crown sealing ring may cause water to seep in when the water pressure exceeds 0.5 bar.
Permanent compression deformation
Symptom: The sealing ring cannot return to its original shape after long-term compression, resulting in an increase in the sealing gap.
Impact: For example, the rear cover sealing ring of a watch may lose 0.2mm in thickness due to long-term compression, potentially reducing the water resistance level from 100 meters to 30 meters.
II. Common factors accelerating aging
Environmental factors
High temperature: Long-term exposure to an environment above 40°C (such as in a car during summer) will accelerate rubber oxidation.
Ultraviolet rays: Direct sunlight causes cracking on the surface of the sealing ring, especially for transparent or light-colored rubber.
Chemical substances: Sweat, cosmetics, and salt from seawater may corrode the rubber material.
Usage habits
Frequent operation of the crown: Daily multiple adjustments of time or date will accelerate the wear of the crown sealing ring.
Not tightening the crown: If the screw-in crown is not fully tightened, water may seep through the gaps.