In the world of horology, the gasket is one of the smallest yet most essential components of a water-resistant watch. Often overlooked by owners, gaskets play a critical role in keeping moisture, dust, and debris out of the watch case, thus protecting the intricate movement inside. For modern sports watches, vintage timepieces, and high-end luxury models alike, routine gasket replacement is fundamental to preserving water resistance and overall watch longevity.

At Steven Hale Watch Restoration (SHWR) in London, we encounter many cases where a damaged or neglected gasket has led to avoidable — and sometimes costly — water damage. This article will explore what gaskets do, why they need replacing, and how SHWR approaches gasket servicing with the highest standard of care.

What is a Gasket and What Does It Do?

Gaskets are thin, ring-shaped seals typically made of rubber, silicone, nylon, or PTFE (Teflon), designed to prevent the ingress of water and air into a watch case. They are fitted into key access points of the watch:

• Caseback gasket – seals the back of the watch

• Crown gasket – located around the winding stem or inside the crown

• Crystal gasket – positioned under the watch glass

• Pusher gaskets – found in chronographs or digital watches with external buttons

• Helium escape valve gasket – for specialist dive watches

These components compress when the case is assembled, creating a tight seal that resists external pressure and prevents leaks.

Why Gaskets Deteriorate Over Time

Despite being made from durable materials, gaskets have a limited lifespan. Over time, several factors can degrade their elasticity and sealing effectiveness:

1. Environmental Exposure

UV light, heat, cold, sweat, and chemicals (like soap, perfume, or chlorine) gradually break down rubber gaskets. Outdoor exposure accelerates this process, especially for watches worn daily.

2. Natural Ageing

Rubber naturally hardens and loses flexibility over time. Even if a watch is seldom worn, gaskets can become brittle and form micro-cracks, especially in vintage models.

3. Mechanical Wear

Frequent winding, crown adjustment, or pressing pushers causes gasket compression and friction, wearing them out faster. Crown gaskets are particularly susceptible to this kind of stress.

4. Improper Storage

Leaving a watch in a humid or excessively hot environment can deform gaskets, while dry conditions may dry out rubber-based seals.

Once a gasket is compromised, even a splash of water or sudden humidity shift can lead to condensation or full water ingress.

Signs Your Watch May Need a Gasket Replacement

Although gaskets degrade gradually, certain signs suggest it may be time for a replacement:

• Moisture or fogging under the crystal

• Rust or corrosion on the caseback or movement

• Loose or unusually soft crown

• Unusual smell or residue around the case edge

• Past due for a service (gaskets should be inspected during each watch service, typically every 3–5 years)

Gasket Replacement: Why It’s Essential

1. Maintaining Water Resistance

The primary reason for replacing gaskets is to maintain the manufacturer’s stated water resistance level. Even watches rated at 200m+ are not immune — without functioning seals, their water resistance is no longer reliable.

2. Protecting the Movement

Modern watch movements contain dozens, if not hundreds, of finely tuned components. Even a few droplets of water can corrode bridges, gears, screws, and jewels. In high-end watches, replacing movement components can be costly — and in some vintage models, parts may no longer be available. Preventative gasket maintenance avoids these risks altogether.

3. Preserving the Dial and Hands

Moisture damage can cause dials to bubble, hands to oxidise, and lume to degrade. Replacing these components reduces originality and value, particularly in collector-grade watches.

4. Upholding Manufacturer Warranty

Many watch brands specify routine gasket maintenance as a requirement for preserving warranty coverage. Ignoring this could void your protection, particularly for newer watches.

SHWR’s Professional Gasket Replacement Process

At Steven Hale Watch Restoration, gasket replacement isn’t just a quick fix — it’s part of a broader watch health strategy. Whether your watch is a waterproof diver or a heritage dress watch, our approach follows a comprehensive, high-precision process:

1. Full Water Resistance Inspection

Before gasket replacement, we assess the current condition using pressure testing machines. This includes both dry testing (to detect case leaks via pressure differentials) and wet testing (to simulate immersion in water). These tools allow us to pinpoint failing seals and determine the exact water resistance level.

2. Gasket Identification and Selection

Using our extensive catalogue of OEM and aftermarket components, we match the exact gasket specifications. For rare or vintage models, we may custom-cut gaskets to size to preserve fit and function.

SHWR always selects high-quality materials appropriate to the watch type and usage. For instance, Viton gaskets may be chosen for chemical resistance in professional dive watches, while silicone gaskets are ideal for vintage pieces due to their pliability.

3. Cleaning of Housing Surfaces

All mating surfaces — case grooves, threads, and flanges — are cleaned and inspected. Residue or corrosion can affect the seal, so precision cleaning ensures the new gaskets seat properly.

4. Lubrication of Gaskets

Gaskets are lightly lubricated with silicone grease to enhance flexibility and sealing ability. This also prevents friction-related wear during movement (e.g., opening a screw-down crown).

5. Installation and Re-Sealing

Each gasket is installed with care to avoid twisting, stretching, or pinching — all of which can lead to future failure. We reassemble the case and re-check alignment.

6. Final Pressure Testing

After reassembly, the watch undergoes a final pressure test to ensure water resistance is within acceptable limits. Results are shared with clients, often accompanied by service documentation.

Case Example: Rolex Submariner with Worn Crown Gasket

A Rolex Submariner came into SHWR with mild condensation inside the crystal after a pool swim. On inspection, we discovered the crown gasket had compressed and lost its elasticity.

Our team replaced the crown tube gasket, the main caseback seal, and re-lubricated all seals. After reassembly and testing, the watch passed a 300m pressure test — restoring its dive-readiness and peace of mind for the owner.

How Often Should Gaskets Be Replaced?

There’s no one-size-fits-all rule, but general recommendations include:

• Every 1–2 years for watches regularly exposed to water

• Every 3–5 years as part of routine servicing

• Annually for professional divers or watches used in harsh environments

• Immediately if water ingress, fogging, or gasket damage is suspected

SHWR recommends an annual water resistance test to catch early signs of gasket fatigue — a quick, non-invasive service that could prevent major repair costs.

Gaskets and Vintage Watches: A Special Note

Vintage watches require extra care. Original gaskets may no longer be available, or cases may not conform to modern sealing methods. At SHWR, we offer custom gasket solutions tailored to vintage models, ensuring water resistance is preserved without altering originality. In some cases, we advise limited exposure to water and focus on creating a “splash-resistant” seal where full waterproofing isn’t feasible.

Conclusion: Don’t Let a Simple Gasket Fail You

Gaskets may be tiny, but they guard against one of the biggest threats to your watch: water. Regular gasket inspection and replacement is essential not only to retain water resistance, but to preserve the life and value of your timepiece.

At Steven Hale Watch Restoration, we combine traditional craftsmanship with modern techniques to deliver gasket replacement and pressure testing to the highest standard. Whether you’re a professional diver, a vintage watch enthusiast, or a luxury collector, SHWR ensures your watch stays sealed, safe, and secure.

Don’t wait for signs of water damage. If it’s been a few years since your last service, or your watch is showing signs of exposure, contact SHWR today for a professional inspection — because prevention is always better than repair.