Watch Care Guide



In this guide


The importance of watch care

Although we take it for granted, watches are sophisticated instruments that you wear on your wrist every day. Like jewellery, looking after something as delicate as a watch is important to keep it looking good and keeping time.. Water resistance, material and technical features can all be very different between watch brands.

This is why we advise you to view the operating manual and manufacturer recommendations as well as seeking help from professional jewellers & watchmakers where possible. Having said that, there are plenty of effective care steps you can perform at home to keep your watch working and looking like new.



Is my watch water resistant?

On a watch case-back you will often see a reference to its water resistance/waterproof rating shown as ATM, Bar, or written on the dial such as ‘100m’. If a watch does not have this on the case-back it is not water resistant.

ATM is an abbreviation of the word atmospheres, and is the scale used to denote the water resistance of a watch. There are different ATM ratings, but they can be misleading. To provide a rating tests are conducted to measure the water resistance of a watch, but are performed in 100% still water.

In theory 10 atmospheres means the watch can withstand 10 times the pressure at sea level without allowing water in - this is equivalent to being 100m underwater. However, moving water exerts more pressure than still water, so you couldn't safely dive to 100 meters with it a 100M resistant watch.

Swimming at the surface of a swimming pool could subject a watch to 3 atmospheres of pressure but jumping or diving in would add more. Below is a helpful guide to tell you what your watch would be suitable for.

Water resistance ratingAccidental splashing from washing hands, rain etc.Showering or swimmingSwimming or snorkellingSwimming, snorkelling, skin divingScuba diving
'Water Resistant' or 30m (3bar) No No No No
50m (5 bar) No No No
100m (10 bar) No No
300m (30 bar) No
500m (50 bar)

Watch Crystals/Glass

The crystal or glass of a watch can be made of a few different substances so they can wear differently from one another. Certain brands have their own names or special types of crystals they fit to their watches but the most common crystal types are; mineral crystal, sapphire crystal and plexiglass.

  • Mineral crystal – probably the most popular of watch crystals. A cost effective hardwearing substance. Mineral crystal can scratch and chip through daily wear and tear just like anything else, but the good news is that it is cheaper to replace than other crystals.
  • Sapphire crystal – most commonly found in higher end watches. The sapphire crystal is the least prone to scratching and chipping of any watch crystal, but it is not impossible to do! Sapphire crystal can be repolished when scratched so can last a lifetime.
  • Plexiglass – usually found in more vintage/domed style watches. Plexiglass is a light weight plastic which can be scratched but is very unlikely to break due to its added durability.




How to clean your watch case


How to clean your watch strap


Battery and Mechanical care

Watch Servicing

  • A good watch is an investment, and so we recommend regular servicing to maintain all the moving parts and ensure your timepiece will keep working at it’s best, and become an heirloom to pass down through generations.
  • You should schedule a maintenance service every few years, although that is dependent on the model and your personal use. Servicing a quartz movement will generally involve replacing most internal parts as well as the battery to get it back to pristine working condition.
  • For automatic and mechanical wind watches a service will generally involve replacing the crown, gaskets, and a general quality check of all the moving parts, replacing any that are worn or cause the movement to run slowly.
  • Most service centres will only maintain the internal movements when it comes to servicing. Glass, straps and casing are not generally covered so, if any of this needs work, it will be in addition to the standard service. Straps, bracelets and glass won’t be covered by a service or any warranty.
  • We recommend a full service every 5 years on average - again, you may feel this needs to be more often. The more in-depth service will include all of the above, as well as the movement undergoing a full dismantling, cleaning, oiling, recalibrating and reassembly. This may sound extreme, but when you consider that over those 5 years, the minute hand will travel over 5000 miles round the dial, a full tune-up will ensure it will keep ticking for the next 5000!


Things to avoid

Prolonged sunlight exposure can affect battery life and fade colours, and so when your watch is not on your wrist, make sure it is kept in its box away from direct light sources.

Extreme temperatures (over 60°C and under 0°C) can cause major damage to the mechanisms.

Chemicals such as perfumes, detergents, cosmetics and solvents (can tarnish metal and damage leather).

Although some watches have some impact resistance, knocks and bumps can still damage the delicate mechanisms and case.

Magnetism - magnetic fields can affect how well your watch keeps time, making it run fast, slow, or stop completely. Magnetic fields are given off by electronic equipment such as computers, smartphones, and speakers, as well and fridge magnets and handbag clasps.


Frequently asked questions

Can you help with watch parts?

For all our brands listed on our website, we keep up-to-date repair price lists, and so can easily quote for parts and services in store. For vintage models or for brands we don’t stock, we can send off for estimates for repair work required.

Do you provide a guarantee?

James Porter & Son are an authorized dealer for all brands stocked so any repairs come with a certificate of workmanship and a new guarantee period of any repairs carried out on our behalf.

Can you help with pressure testing?

In store we can fit replacement batteries. We cannot carry out pressure testing, so we only work on watches that do not require being resealed for immersing in water. For utility watches like G-shock, Seiko Prospex, and Luminox we always advise returning these to the authorised service centres to have the proper pressure testing carried out.

Do you stock replacement watch straps?

For replacement straps, we keep a stock in store in various colours and sizes. For branded straps we can replace and fit in store.

Get in touch

Contact us by phone at 0141 221 5855 or by email at We love our work and will be happy to help you with your query, we can also book a convenient time for a consultation to find the exactly what you need.

Simon Porter

Simon Porter

Director, James Porter & Son

Simon is the 5th generation Porter to look after the day to day running of the James Porter & Son store since its inception in 1858. Working alongside his father since 1995 and eventually taking over the reins full time in 2007.

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