A well-built Seiko mod is a precision instrument. Treat it with the same respect you'd give any quality mechanical watch and it will reward you with years — potentially decades — of reliable service. Neglect it, and even the best movement will let you down.
This guide covers everything you need to keep your ZJani Mods piece performing at its best.
Daily Wear: What to Watch Out For
Mechanical watches are robust, but they're not indestructible. A few habits will extend the life of your watch significantly:
- Avoid strong magnetic fields. Mechanical movements are susceptible to magnetisation, which can cause erratic timekeeping. Keep your watch away from speakers, magnetic closures, and MRI machines.
- Don't wind the crown while wearing the watch. Remove it from your wrist first to avoid putting lateral stress on the crown stem.
- Screw down the crown before water exposure. This is the single most important step for maintaining water resistance. A crown left unscrewed will allow water ingress regardless of the watch's rated depth.
- Avoid extreme temperature changes. Moving rapidly between very hot and very cold environments can affect the lubricants inside the movement.
Cleaning Your Watch
Regular cleaning keeps your watch looking sharp and prevents the build-up of salt, sweat, and grime that can degrade gaskets over time.
The Case and Bracelet
After exposure to saltwater or sweat, rinse the watch under fresh running water with the crown screwed down. Use a soft toothbrush to work into the bracelet links and case lugs where debris accumulates. Pat dry with a lint-free cloth.
For a deeper clean, a small amount of mild soap can be used on the case and bracelet. Avoid harsh chemicals, solvents, or ultrasonic cleaners unless you're confident the gaskets are in good condition.
The Crystal
Sapphire crystals are highly scratch-resistant but not scratch-proof. Clean with a soft microfibre cloth. For minor surface marks, a small amount of watch crystal polish can restore clarity — apply sparingly and buff in circular motions.
The Dial
Never attempt to clean the dial yourself. It's delicate, and any contact risks damaging the printing or lume. If the dial needs attention, it should go to a watchmaker.
Crown and Gasket Care
The crown gasket is your watch's primary defence against water ingress. Over time, gaskets compress and degrade — this is normal, and it's why water resistance ratings are not permanent.
As a general rule:
- Have gaskets inspected and replaced every 2–3 years if you swim or dive with the watch regularly.
- Have gaskets inspected every 3–5 years for watches worn primarily on land.
- After any crown service or caseback opening, always have the watch pressure-tested before water exposure.
Storage
When you're not wearing your watch, store it properly:
- Keep it away from direct sunlight. UV exposure can fade dials and degrade rubber straps over time.
- Store in a cool, dry environment. Humidity accelerates gasket degradation and can cause condensation inside the case.
- Use a watch box or roll. This protects the crystal and case from scratches and keeps dust out.
- For automatic watches not worn daily, a watch winder will keep the movement running and the lubricants distributed. Alternatively, simply wind the watch manually before wearing.
Service Intervals
A mechanical movement requires periodic servicing — cleaning, lubrication, and adjustment by a qualified watchmaker. This is not optional; it's the equivalent of an oil change for your car.
For NH35A and NH36A movements (the most common in Seiko mods), a service interval of 5–7 years is generally recommended under normal use. Signs that a service is overdue include:
- Timekeeping accuracy has deteriorated significantly
- The rotor feels rough or gritty when the watch is moved
- The watch stops unexpectedly despite a full power reserve
- Visible moisture or condensation inside the crystal
Strap Care
Straps take more wear than any other part of the watch and need their own attention:
- Leather straps — avoid prolonged water exposure. Rotate straps regularly to allow drying between wears. Condition occasionally with a leather balm.
- Rubber/silicone straps — rinse after saltwater exposure. Inspect for cracking or stiffness, which indicates the rubber is degrading.
- Metal bracelets — clean regularly as described above. Check clasp function periodically and have a watchmaker tighten any loose pins.
When to See a Watchmaker
Some things should always go to a professional:
- Any moisture inside the case
- A damaged or loose crown
- Significant impact (dropping the watch on a hard surface)
- Timekeeping that's suddenly off by more than 30 seconds per day
- Any caseback opening — always have it pressure-tested afterwards
Built to Last
Every watch from ZJani Mods is assembled with quality gaskets, pressure-tested before shipping, and built to be worn. Follow this guide and your piece will serve you well for years to come. If you have questions about caring for your specific build, don't hesitate to get in touch.
