Quartz Watch Maintenance and Repair

At Joyería Sendra, we want to help you understand watches in a way that's both professional and approachable, which is why we're bringing you a series of blog posts to answer your questions and help you learn a little more about these beautiful precision timekeeping instruments.

This time we're covering maintenance and repair services for a quartz watch.

1.- Basic Battery Replacement:

Quartz watches are precise and affordable, and they only need a small amount of maintenance, which is usually very quick. In most cases, that maintenance simply means replacing the battery, and this can normally be done correctly in under 5 minutes. But even though it's quick and inexpensive, it's a process that should be carried out by a qualified, trained watchmaker; and so that you don't think this is just a throwaway line meant to discourage you from doing it yourself, let us explain that there are real reasons behind it and that the specialist's work is genuinely justified — let us walk you through what's involved and why it should ideally be done by a certified watchmaker. That way, if you do decide to try it yourself in the end, at least you'll know exactly what you're getting into.

Even though quartz movements are, for the most part, genuinely inexpensive and extremely common today, it's worth remembering that they are instruments of extreme precision. A day has 86,400 seconds, so a watch that gains or loses 15 seconds a day still keeps an accuracy of 99.9826%, and quartz watches rarely gain or lose more than 2 seconds a day (the usual tolerance being 15 seconds a month), although real-world accuracy is estimated at around 30 seconds a year. This is because the accuracy of quartz can vary with temperature, but since temperature fluctuates throughout the day and from one day to the next, these variations tend to cancel each other out, so real accuracy is actually higher when measured over a full year than day by day.

Because of this precision, watches are extremely delicate machines, although the case makes them far more resistant to knocks, vibration, temperature changes, magnetic fields, and so on. In fact, unless the watch is a mechanical piece with major complications, the case and other external components are the main focus of attention and the clearest expression of the watch's quality and the justification for its price — although this is a secret watchmakers rarely admit to.

So, once we understand that a watch is a delicate instrument, it becomes clear why it's so important to leave it in good hands if we value it, and if the watchmaker is trustworthy, the price we pay is a fair one for the work involved. Here, we'll help you understand why.

To start with, let's look at some of the most serious and common problems we see in our shop with work carried out by other watchmakers or by people without much expertise. This isn't meant as criticism — it's simply a statement of fact:

• Wrong battery: There are many different watch movements. Some are very common, while most movement references are fairly specific. For example, some have moon-phase complications, but very few watches actually use them. Some movements are modified versions of others, mainly for space reasons or to change the position of the date window. But every movement requires the exact battery it was engineered for — engineers put real work into that — which is why each of the several dozen button-cell battery references out there comes in a different size. Almost all watch batteries run at 1.55V, but each one can deliver a different amperage, so if the wrong one is used, it will eventually damage the movement by putting strain on the coil and other components, and each subsequent battery will drain faster and faster. This is a natural process in quartz watches, since the electronics eventually fail due to the ordinary entropy of physical materials, but it usually takes a long time to appear — somewhere between 12 and 20 years of continuous use. Using the wrong battery, on the other hand, is enough to shorten that process to as little as 2 years, and the damage is irreversible. Fitting the wrong battery can also mean using one that's thicker than it should be, putting strain on the gear train, or one that's too small and shifts around, causing poor contact — both of which harm the watch's performance and can leave lasting damage. Most watches use 364 and 377 batteries, which also happen to be by far the cheapest (probably because their high demand keeps manufacturing costs down), and that's why many \"battery-swap shops\" only stock those two to shave off a few cents. This is a serious mistake, and the only way to guarantee a proper service is to go to a genuine specialist.
• Fingerprint marks: A very common mistake, even among old-school watchmakers, is touching the battery directly with a finger. This isn't about the extreme cases of real damage — we'll leave those aside — but on some watches that come into our shop, you can see a fingerprint smudged across the entire movement, left by whoever previously changed the battery without really knowing what they were doing, even if they'd done it thousands of times. This might sound trivial, but the small amount of natural oil left behind by a finger can eat away at the battery's protective coating over time and allow micro-corrosion to start forming. Remember that every time the battery is changed, fresh air gets into the watch, and where you have an electrical current and oxygen together, corrosion is eventually going to appear. You can never be too careful. Battery changes should be done without ever touching the battery or the inside of the watch with bare fingers. Batteries should be handled with proper tweezers, and if pressure needs to be applied to seat them, you use the back of the tweezers or a finger fitted with a silicone finger cot — sometimes called a \"thimble\" — designed specifically for this purpose, and only specialized workshops tend to have this tool on hand, simple and inexpensive as it is. And if there's ever accidental contact, or if the watch's design makes it unavoidable to use your hands to fit the battery, the area should be cleaned with a leather stick tool known as a crampon. The important thing is to leave no lasting marks on the watch at all, or to minimize the impact if any occur.
• Removing or mishandling the gasket: On a water-resistant watch, the gasket needs to be in perfect condition, but even when it isn't, it's still an essential part. If a plastic gasket isn't in good shape, it will end up completely deformed once the case is opened. Before the watch is opened, a worn gasket can still do its job because it's held under pressure in its housing, but if it's not in good condition, opening the case will leave it deformed and no longer fit to be reused — in some cases the deformation is very obvious, or the gasket may even be broken in several places. The watchmaker should inspect the gasket even during a routine battery change, even if the customer hasn't asked for anything else, since gaskets are inexpensive and professional watchmakers usually keep a full stock of the many sizes needed. If the gasket isn't in good condition, the watchmaker should replace it (we do this at no extra charge to the customer) and let the customer know exactly what work was carried out on their watch.

2.- Basic Maintenance Service:

Whenever a customer would like it, we can offer their watch a basic maintenance service to ensure it keeps working properly. This usually consists of:

• Basic battery replacement
• Gasket replacement and water-resistance testing
• Checking the watch's power consumption and accuracy

It's essential that the battery be replaced every time the case of a battery-powered watch is opened. To properly assess the condition of a watch, it helps to know, at least approximately, how long the current battery has been in use, so whenever possible, let your watchmaker know when the battery was last changed, since this can be a useful diagnostic clue — and the best way to keep track is simply to remember the date of the last replacement for your watchmaker. If we bring a watch in for servicing and the battery isn't changed because it seems to be in good condition, that's not only inefficient, we also run the risk of forgetting and later assuming the battery was replaced when it wasn't. Once the case has been opened, the battery should be changed even if it was replaced only a few months earlier, since opening the watch repeatedly should always be avoided.

Gasket replacement covers the case-back gasket, cleaning the crown and pusher tubes (where fitted), cleaning the inside of the case, and replacing the gaskets on those tubes, and can occasionally also involve removing the crystal, replacing its gasket, and resealing it if the watch is a few years old or shows scratches on the crystal or case. Crystals are fitted using a special adhesive that cures under ultraviolet (UV) light, so a UV lamp is required to seal them properly, and this type of lamp isn't available in every workshop (although it's the same, or a similar, lamp to the ones used for curing nail gel polish).

Water-resistance testing consists of replacing these gaskets as described above, greasing them with a silicone-based grease, and then carrying out the well-known vacuum test. Some customers mistakenly believe the watch itself is placed under pressure during sealing, which is incorrect. We've even had customers insist they've seen a watch \"sealed\" by placing it inside a hyperbaric chamber. That is a serious misconception. It's the testing, not the sealing, that's carried out under pressure — both negative and positive — and these tests simply study crystal deformation or condensation inside the watch to determine whether it's fit for contact with water. Sealing a watch \"under vacuum\" or under pressure could seriously damage it if the watch were later exposed to conditions noticeably different from those under which that botched job was done, for example leaving it in the sun or taking it off on a very cold night. The physics involved is simpler than it sounds.

Power consumption is checked with the battery removed from the movement, by connecting a specialized watchmaker's tool (in our case, our timing machine handles this) to the circuit's contact points at the specified locations — usually the same contacts where the battery sits. This tool gives us the peak current draw, which we then compare against the manufacturer's specified consumption range and tolerance. If the movement draws more current than the manufacturer specifies, the customer should be informed, along with a repair quote, so they can decide how to proceed. In quartz watches, the best fix is usually a full movement replacement, although for a small number of watches it can make more sense to service the existing movement, which involves the classic \"clean and overhaul.\" Replacing the movement is usually the better option, since it's inexpensive, quick, and gives you a brand-new mechanism — identical to the original but potentially with improvements in performance or accuracy.

Checking the movement's accuracy is also done with the tool called a \"timing machine,\" which uses high-precision sensors to \"listen\" to the watch as the seconds-hand motor runs. After a few seconds, the timing machine gives us the average rate, with a reasonable tolerance of ± 15s/day, although a quartz watch rarely exceeds ±2s/day.

3.- Full Maintenance Service:

The full maintenance service includes everything covered in the basic service, and can additionally include the following work:

• Case polishing: The case is polished to a matte finish that's less prone to showing scratches
• Bracelet polishing: The bracelet is polished to bring it as close as possible to its original finish, in either matte or polished finishes
• Bracelet cleaning: Bracelets can build up grime from everyday wear and the natural oils in our skin. Some people wear their watch in the shower, which we don't recommend, and cleaning the watch with warm soapy water helps offset this, although this isn't great for the watch itself — beyond that, though, it's a completely normal process that has nothing to do with a lack of hygiene. The bracelet is removed and cleaned in an ultrasonic cleaning machine using water and special soap-based solutions designed for the purpose.
• Strap and spring bar replacement: If the watch comes on a leather strap, it may be quite worn and need replacing. This can also be done as a separate service, since leather straps typically last 1 to 4 years depending on the type of strap and how it's used, but if we notice during a maintenance visit that it's due for a change, we can go ahead and take care of it at the same time, finishing the job with a watch that looks \"as good as new.\" In the same way, the spring bars used on both straps and bracelets contain springs that eventually rust. A thorough maintenance service includes replacing these, even if there's no visible sign of wear. The replacement strap can be the original model or a compatible one, and there are some excellent domestically-made options out there. Joyería Sendra's advice is that if you find a strap you love in terms of design, colors, or materials, go ahead and switch it out rather than insisting on the exact original. Unless you're really attached to the original, changing the strap can make the whole watch feel brand new again — it's a genuinely satisfying feeling, and some replacement straps are actually better than the originals.
• Link and clasp inspection: On bracelets, the links are usually held together with screws (on higher-end watches) or, more commonly, with cotter-pin or similar link pins. We carry out a routine check to see whether any of these pins have worn excessively or rusted and need replacing. Similarly, bracelet clasps can have metal springs or fixed parts that loosen and lose tension with use. This can usually be fixed, but customers should understand that metal fatigue makes it progressively easier for a clasp to lose its original firmness — much like bending a thin metal rod, where each bend leaves it a little softer until eventually it snaps. In some cases the clasp itself may need to be replaced, although this isn't very common.
• If the watch has a magnifying crystal over the date window — very typical on Rolex watches — this small crystal is glued in place. Extra maintenance can include removing it, thoroughly cleaning both surfaces, and re-gluing it to keep this component in the best possible condition.
• Dial restoration. On rare occasions, we come across very old watches that were stored in poor conditions — usually due to humidity — leaving the dial darkened or even corroded. As mentioned, this is normally only done for very old watches: the classic \"grandfather's watch\" or a father's watch that holds special sentimental value, or in cases of very visible damage from long-term exposure to water. In these cases, we can offer a dial restoration service, done by hand by specialized companies — of which there are probably only 2 or 3 in all of Spain — that produce truly spectacular results. It isn't cheap, but it's absolutely worth it if the watch needs it.