Watch Care and Repair

Copyright © David Boettcher 2005 - 2023 all rights reserved.

This page is about maintaining (caring for) and repairing a mechanical watch. The object of routine maintenance, cleaning and oiling, is to prevent wear and damage. If this is not done, repairs can be very expensive or even impossible. The subject of watch care falls broadly into three categories:

1. Servicing: Like all mechanical things, watches need cleaning and oiling from time to time.
2. Water Resistance: Water resistant watches don't remain water resistant forever.
3. Don't Drop It: Older watches don't have Shock Protection so can break if you knock or drop them.

You also need to be careful when buying a watch, so I discuss precautions to take so that you don't get stitched up.

Like all mechanisms with moving parts, a mechanical watch movement needs lubricants, oils and greases, to reduce friction between parts that slide against each other. Over time these lubricants dry up and stop doing their job. Or even worse, they absorb dust from the atmosphere and turn into a grinding paste. Because of this a movement needs servicing from time to time to clean out the old oils and greases and replace them with fresh. If you don't have a watch serviced, it will continue to run for quite a long time, but friction will be causing internal wear. When the watch does eventually stop, which it inevitably will, it will be very expensive, or even impossible, to get it repaired. See Watches Need Servicing for why this is.

If you are simply looking for a reliable repairer, the best place to start is the list of accredited repairers on the web site of the British Horological Institute. However, not all the repairers listed are interested in old watches or capable of working on watches more than twenty or thirty year old. I have had some reported to me who have said that old watches are “not worth repairing”. This is not true and highly unprofessional; if someone says this to you, move on to someone with a better attitude, and please let me know. For more information about how to find a reliable repairer please read the section Finding a Repairer.

Water resistant watches don't remain water resistant forever. Seals and gaskets age and perish, and the manufacturers recommend service intervals because of this. If you don't pay attention and just assume that your watch is water resistant, then water might get in and can cause serious, or even terminal, damage to the movement. If you haven't followed the manufacturers service recommendations you can't blame them.

A favourite phrase of vendors to suggest that a watch that isn't working doesn't have much wrong with it is “over wound”. However, you can't stop a watch by winding it up (although if you are extremely careless or clumsy you might break something). A watch that isn't going might have any one of a myriad of faults, ranging from something very trivial that can be easily fixed to something terminal, but being “over wound” is not one of them. See “Over Wound”??? for the reasons why this is.

Most modern watches, watches made after WW2, have shock protection and will withstand being dropped. But watches from before the war usually do not have shock protection; I explain why in Shock Protection.

If you have any questions or comments, please don't hesitate to contact me via my Contact Me page.

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Watches Need Servicing

A watch needs to be cleaned and oiled every so often because the oils and greases used to lubricate the moving parts thicken then dry out. Oil or grease that is dried out cannot lubricate the moving surfaces adequately and they wear or, even worse, over time oil can mix with dust from the atmosphere to form a grinding paste that wears parts. Spare parts for old watches are often not available, so a worn out part can mean that an old watch cannot be repaired economically or at all; such damage can be terminal.

Modern watches with fully sealed waterproof cases can go longer between services than older watches with less well sealed cases. Case joints that are not well sealed allows dust and fluff into the case. Fluff is a nuisance, but dust is worse because it can combine with oil to form a grinding paste that quickly wears components. Old watches with less than fully waterproof cases should be cleaned and oiled every three or four years, more modern watches with fully waterproof cases can go longer, five or six years.

Watches that are not fully jewelled are more prone to wear of the bearings in the plates, which is where the extra jewels are fitted in a fully jewelled movement. With a watch that has less than 15 jewels, you need to be more alert to the need for regular cleaning and oiling to avoid wear in the plates.

If you wind up an old watch and it seems to be running OK, bear in mind that a watch will continue to run for a surprisingly long time without being serviced, but by continuing to run a watch that has not been serviced you will be building up wear and damage inside the watch that you can't see – see the section below about damaged stem bearings to see the damage that winding a watch everyday can do if this mechanism is not adequately lubricated. This will become apparent when eventually the watch stops, at which point the damage might be so bad that it cannot be repaired.

Replacement parts for old watches are usually no longer available. In theory all the parts can be made for a mechanical watch by a skilled watchmaker, but this is expensive and might not be economic. And some parts are easier to make than others - I wouldn't fancy trying to make a balance spring, and these are now getting in short supply for older watches – even stocks of some mainsprings are running down. And I still haven't repaired the damaged stem bearings shown in the section below. I know how to do it in theory; bore out and sleeve. But in practice, accurately boring and sleeving a bearing in a wristwatch plate a few millimetres thick is not an easy operation without expensive equipment that most watch repairers don't have.

Remember that these old watches have survived through many years and events until now, and it is your responsibility to take care of them and make sure you pass them on in good working condition. A mechanical watch that is regularly serviced could still be working just as well in centuries from now as the day it left the factory; you can't say that about electrical or electronic watches.

Regular servicing is particularly important for old hand wound watches because

• The cases tend to be not very well sealed, especially if they are jointed (hinged), so fluff and dust can get in and mix with the oil form either a sort of gum that can stop the watch working, or worse, a grinding paste that wears the moving parts.
• The keyless mechanism (the mechanism that winds the watch or sets the hands when you turn the crown) of a hand wound watch takes a lot of stress through being used every day, and can wear badly if not adequately lubricated - see the discussion about this in the section below, and the picture of a badly worn bearing.

There are two methods of cleaning and lubricating a movement:

1. The first method places the complete movement in the cleaning machine through a wash and two rinses, the second rinse containing a lubricant, and that's it. There are two problems with this method. It seems to me that the cleaning fluid will not be able to clean difficult to reach places such as the jewel holes with the pivots in them, although I understand that the end or cap stones are removed before cleaning. These need to be cleaned thoroughly to remove congealed oil. Perhaps a powerful ultrasonic machine can do this. I am sure that a single, necessarily very fine, lubricant cannot be ideal for all the different duties of each part of the mechanism, from the fast moving but lightly loaded balance staff to the slow moving but heavily loaded keyless mechanism. This method is certainly quick and cheap, but the downside is probably that it needs to be repeated more often than a full strip and oil.
2. The second method, and the only valid one in my view although it is more expensive, is a full strip, clean and lubricate, where the movement is completely dismantled, the parts are cleaned and rinsed in a specialised watch cleaning fluids, each component then examined for cleanliness and further cleaned if required, e.g. the jewel holes are "pegged out", which means a sharpened piece of special wood is pushed into the hole to remove any last traces of dried gummy old oil, and the movement then reassembled with the correct lubricant applied where it is needed. I use at least four different lubricants depending on the duty of each component, ranging from a grease for the keyless mechanism and barrel arbor pivots where there is high torque and low speed, through to a light oil for the pivots of the faster train wheels, and a thixotropic grease for the escape pallet faces. These specialised oils and greases are very expensive, the grease that is used only on the pallet faces works out at well over £100,000 per gallon! (fortunately I don't buy it by the gallon.)

Before committing your watch to be serviced it is always best to ask which method will be used, simply for the avoidance of doubt. I once purchased some equipment from a watchmaker who used to work for the principal jewellery retailer of a reasonable sized town and an Omega agent. He told me that he used the first method on Omega watches for many years. I was astonished. There is no doubt that a quick dunk like this will get a watch going, but the lubricant carried in the final rinse has to be very thin because it has to go everywhere in the movement without gumming it up, so it doesn't last very long, and it can't adequately lubricate bearings under heavy load such as in the keyless mechanism for winding and setting. More wristwatches are scrapped because of worn out bearings in the keyless mechanism than due to any other reason - see the section on keyless mechanism below.

Stem Bearings

Stem wound and set watches, that is the type of watch that you wind up by the crown and set the time by pulling crown out away from the case, incorporate a "keyless mechanism". It is called this because you don't need a separate watch key to wind or set the watch, hence the watch is keyless. The most common "shifting sleeve" form of keyless mechanism was invented in 1845 by Adrien Philippe, who later joined the Geneva company of Patek to form Patek Philippe. You can read more about the various forms of keyless mechanism at Keyless Mechanism.

The action of turning the crown to wind the watch or set the time is carried into the mechanism by a metal shaft called the "stem". When you pull the crown out to set the time, the stem is drawn out and the keyless mechanism, a system of levers, disengages the winding mechanism and engages the time setting mechanism.

If a watch is manual winding, then it has to be wound every day to keep going. Although the stem winding keyless mechanism is a clever piece of design, the bearings are small and not jewelled and there is no adequate provision to ensure that they remain lubricated. The keyless mechanism is truly the Achilles' heel of a keyless watch.

If a watch is not regularly serviced and grease in the stem bearings renewed they can wear heavily. It is not unusual that a watch that otherwise runs perfectly well becomes impossible to repair because of wear in the stem bearings and keyless mechanism, so it pays to be aware of this potential problem.

Wear in the stem bearings is the Achilles heel of manually wound watches. Automatic watches that wind themselves as the wearer moves around do not suffer anything like as much from this problem, because the stem is only used occasionally.

The picture here shows the outer stem bearing in the bottom plate of a watch. It is very badly worn - the tops of the ridges standing up from the bearing surface give an idea of where the original surface was and how much wear has occurred.

This degree of wear has been caused by the wearer winding his watch while it was on his wrist. Although it is physically possible to slide a finger between the crown and your wrist to wind the watch, this picture shows you why this is a very bad idea. Jamming the finger between the wrist and the crown causes excessive side force on the crown and the stem, which has to be carried by this bearing. And as you can see, the bearing is not adequate to withstand this treatment and wears badly.

The moral of this is: always take off your watch to wind it, avoid applying sideways force to the crown, and have the watch serviced regularly to get the stem bearings lubricated. If you wait until your watch stops running or you can no longer wind it, it might be too late!

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Spare Parts

Sometimes people try to identify a movement because it needs repair or they are trying to find spare parts. This raises the question of what spare parts might be available for an old watch.

Manufacturers usually try hold complete stocks of parts for movements for 15 to 20 years after the movement ceases to be made. After this, the availability of spare parts starts to decrease as the stock of parts is used and not replaced. This sounds like bad news for watches made more than 20 years ago, and indeed it can be, but some parts are more difficult to replace than others.

For watches made after the second world war (WW2), there are quite good supplies of spares available, although these are often “New Old Stock” (NOS) found at trade fairs, specialist markets and on internet auction sites. It helps that movements of this age are usually marked with a manufacturer's trademark and calibre reference.

Some generic parts are frequently available for even older watches. These are parts that would be expected to be changed during the life of the watch. These were often also made by third parties such as staffs and stems by Ronda. Because these parts were regularly replaced, large numbers were made and new old stock can often be found. These components are:

• Crystals
• Mainspring
• Balance staff
• Winding stem
• Jewels: bearing holes, end stones, impulse pins, pallets

Parts of a watch that are difficult or impossible to replace if the manufacturer's stock has run out are the plates, cocks and bridges, and the mobile components that sit between them such as the mainspring barrel, wheels and arbors, the escape lever, the balance and balance spring.

If parts are no longer available off the shelf, one option is to source them from another movement. Depending on the part, you might need to find an identical movement, or parts from another movement of the same size and similar date made by the same manufacturer might be interchangeable. Components made by third party manufacturers, such as mainspring barrels, are also sometimes interchangeable.

For watches made in the 1930s and before, often spares were not made available by the manufacturer at the time, so the possibility of finding New Old Stock is vanishingly small. Another problem is that the movements were not identified by calibre reference, and often even working out who made a movement can be difficult. When this is the case, finding parts is doubly difficult, because even if someone has an identical movement with good parts, they don't know what it is either, so they don't know what to advertise it as and you don't know what to search for. The chances of you finding that movement are pretty well zero.

If the balance spring is damaged, it can be replaced with a generic replacement. But this needs to be “vibrated” to the balance, which means finding the exact length of spring that gives the balance the correct frequency of vibration, then cutting the spring slightly longer than this so that it can be fitted to the stud. This is job that requires a lot of practice; it is easier to take a balance and spring from a movement of the same size and vibrations and replace the balance and spring as an assembly. This often requires a new balance staff to be made that fits the bearings of the watch and the hub of the balance.

If parts cannot be found, then the only alternative is to make them, or have them made. Any part can be made, but this will be expensive and economic considerations may dictate whether this is an option.

People sometimes ask whether an old watch is “worth” repairing. If this is because the watch is to be sold, then the answer is usually no; the cost of the repairs will be more than any increase that might be achieved in the sale price. But if it is a treasured item of family history that holds valued memories of people no longer alive, then it is worth more than money. It is down to the owner to decide how much money they want to spend.

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Finding a Repairer

I have learnt to service, repair and restore my own watches. It takes time and a little money to accumulate the skills and tools to do this, but if you have inclination, patience and good dexterity you can learn to do it. There are two ways to learn, either by trial and error, best done on scrap bare movements which can be bought cheaply from e.g. ebay, or by taking instructional courses. Taking courses is the quicker route, you will be shown how to work effectively and avoid mistakes. I can recommend the courses run by the BHI at Upton Hall. In either case you should get a good book and read it thoroughly, one of the best is Hans Jendritzki's “The Swiss Watch Repairer's Manual”. Sorry, I don't have the time to work on watches for other people.

If you don't want to do your own servicing and repairs, you need to find a competent watch repairer. Before you hand over your treasured watch you must, and I can't emphasise this strongly enough, you must make sure that the person who is going to work on it is competent in servicing and repairing the type of watch. You might think that all mechanical watches are much the same, but there is a big difference between post-WW2 watches, which are easy to work on and where spares and spare movements can be available, and watches made before WW2, which almost inevitably require that replacement parts are custom made. Watches that are older still, e.g. from the Great War era, or the nineteenth century, present their own challenges.

A local watch mender who can change wrist straps and batteries is very unlikely to be familiar with old mechanical watches, despite what they might say. Even someone who is capable of servicing a modern, post WW2, mechanical watch may be only used to fitting manufacturer's replacement parts, which are simply not available for older watches. I have seen some real disasters from going down the high street route. If you do choose to try a local person, or someone recommended or used by a high street shop, be on your utmost caution, and do not automatically believe everything they say. Here is an amusing anecdote from one of my customers.

If you can find a “trusted local jobbing watchmender” like this, then you are in luck and do let me know their details! On a typical high street you are more likely to find the first type of place.

Many years ago I entrusted a watch of mine to a jewellers in a nearby upmarket town who describe themselves as specialists in elite jewellery and prestige Swiss watches. They persuaded me that it was not necessary to send the watch to the manufacturer's service agent because their own service department could do it just as well, and more quickly and cheaply. They didn't change the case seals before testing the watch for water resistance, which it naturally failed and they noted on the invoice. But in the process water had got into the case and that evening I saw droplets of water condensing inside the glass. Even though I immediately took the back off and pulled the movement out, the dial, hands and movement were all ruined. They were replaced by the manufacturer's service agent, who also changed the case seals and guaranteed that the watch was waterproof. It was a very expensive lesson.

Watch repairers who are prepared to spend the time and have the necessary skills to work on older watches are few and far between. Make sure you ask questions and are confident in the abilities and willingness of the person to take on the job. Don't be afraid to post your watch to somebody qualified and competent using a tracked service such as Royal Mail Special Delivery.

If you have had a good experience with a repairer, especially with a trench watch, an old wristwatch (by which I mean at least pre-WW2) or a pocket watch, please let me know so that I can add them to this section.

BHI Registered Repairers

A good source of qualified and competent watch repairers are the lists of accredited wristwatch and pocket watch repairers to be found on the BHI Web Site (they keep moving the page so I can't link to it directly – look for the link ‘Find a Repairer’). However, although all the repairers on the BHI list have taken and passed exams at the BHI, not all of them have experience of, or are willing to work on, very old watches like trench watches, or even much more recently made watches.

The BHI courses and exams are mainly about modern watches for which there are spare parts available, which usually means watches made in the last twenty or thirty years. Parts for older watches, aside from generic items such as crystals and mainsprings, are often no longer available. This makes some people reluctant to even attempt to service an older watch, although in many cases such watches can be serviced perfectly easily.

It shouldn't happen with members of a professional body, but I have had reported to me BHI listed repairers who have told people that their treasured watch or inherited heirloom is “not worth repairing”. As a Fellow of the BHI I am always trying to stamp out this sort of behaviour; no one in the profession should pass such an opinion on a customer's possessions. It is usually given because it is not worth it to the person giving the opinion rather than to the owner of the watch, or because they don't have experience of repairing older watches and don't want to risk trying.

If you contact someone on the BHI list, make sure you ask whether they have experience and are happy to work with watches like yours. If they don't pass muster, or they tell you that it is not worth repairing, move on to another person on the list and also please let me know. You will find someone; any watch can be repaired.

The BHI lists covers all areas of the UK as well as some other countries, but don't just try to find someone local to you. If you restrict yourself to someone local you might not be using the best person for the work.

USA

I have not used many watch repairers in the USA, but I have had good service from Denis Carignan at Carignan Watch Company, and John DiDonato at Farfo.

If you can recommend any other watch repairers in the USA, or anywhere else, please let me know.

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Water Resistance

The term “waterproof” is not used for watches today, recognising that such an absolute standard cannot be achieved. Instead it is replaced by “Water Resistant” along with a pressure rating in atmospheres and metres or feet of water, which gives an idea of just how water resistant the watch is. There are two international standards that regulate the testing of watches, ISO 22810:2010 Horology - Water-resistant watches, and ISO 6425:1996 Divers' watches.

The normal pressure of the atmosphere atmosphere at sea level is about 14½ pounds-force per square inch (psi) or 1 bar - a standard atmosphere is 1.01325 bar. This is equivalent to a column of mercury in a barometer of 29.92 inches or 33.9 feet of water, which is about 10.3 metres of water. So one bar pressure is equivalent to about 10 metres water gauge or depth under water.

A watch that is described as water resistant might be less waterproof than you might think. A watch rated at 3 atmospheres (3 atm) or 30 metres / 100 ft water depth might seem at first sight to be more than adequate for swimming or showering. After all, you are hardly likely to get 100 feet deep in a swimming pool! However, this rating is a static pressure that the watch was tested to when it was new. There are all sorts of reasons why a watch of this rating is not suitable for swimming, such as the pressure is increased by movement - diving into water, or the jet from a shower create a much higher dynamic pressure. And that pressure rating was recorded when it was new - over time the seals deteriorate and need to be renewed. Unless a watch has been tested for water resistance within the last year, you should assume that it is NOT water resistant. If it has been tested, the certificate will tell you its level of water resistance.

1. Watches rated at 3 atmospheres / 30 metres are resistant to rain or splashes from hand washing, but are not suitable for swimming or wearing in the shower.
2. A watch rated at 5 atmospheres / 50 metres will tolerate gentle showering, but not power showers or jumping or diving into water.
3. For swimming, water resistance of at least 10 atmospheres / 100 metres is required.
4. For sub-aqua, water resistance of at least 20 atmospheres / 200 metres is required.

Watches don't remain water resistant for ever. Before a watch described by the manufacturer as water resistant left the factory, it was tested and carried a time limited guarantee. When it was subsequently serviced at the specified interval, the water resistant seals should have been renewed and the water resistance tested and guaranteed again. A factory licensed watchmaker would do this, but they are expensive and people often shop around for a cheaper price.

Machines for testing water resistance are relatively expensive, and one of the easiest things to leave out that doesn't appear to affect the going of the watch is changing the seals. Both of these factors make the job cheaper, and the receipt usually has “water resistance not tested or guaranteed” stamped on it so there is no mistake. Such a watch must never be exposed to water, even when washing hands it should be taken off first.

Many years ago I entrusted a valuable watch of mine to a swanky jewellers in a nearby posh town, who described themselves as specialists in elite jewellery and prestige Swiss watches. They persuaded me that it was not necessary to send the watch to the manufacturer's service agent because their own service department could do it just as well, and more quickly and cheaply. They didn't change the case seals before testing the watch for water resistance, which it naturally failed and they noted on the invoice. But in the process water had got into the case and that evening I saw droplets of water condensing inside the glass. Even though I immediately took the back off and pulled the movement out, the dial, hands and movement were all ruined. They were replaced by the manufacturer's service agent, who also changed the case seals and guaranteed that the watch was waterproof. It was a very expensive lesson.

If you are concerned about the water resistance of your watch, a very simple test is to place an ice cube on the glass and, after a while, look for signs of condensation on the inside of the glass. A very small amount of condensation is acceptable, after all, all air contains some moisture in the form of humidity which will have been trapped inside the watch when it was closed up. But more than a small trace is a cause for concern and you should get it professionally checked.

The bottom line: water getting into a watch can be a disaster. The steel parts rust and the watch can quickly become unrepairable. Economy here can easily turn out to be false economy! If your watch is not highly water resistant, or you are not sure how water resistant it is, don't take chances, keep it dry. If you want to splash about in the shower, swimming pool, or in the sea, get a properly water resistant 100m+ watch, get it tested and the seals checked and replaced regularly, and then don't worry about it.

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Shock Protection

The pivots of the balance staff of a watch are made very thin to minimise friction, and are therefore delicate. If a watch is dropped or knocked, the shock can cause the balance staff pivots to bend, or more usually to break because they are very hard and brittle, causing the watch to stop or run inaccurately. Pocket watches and early wristwatches were both subject to this problem. It was not so much of a problem for pocket watches, which were normally kept in a pocket and only received a shock if accidentally dropped, but wristwatches are in a vulnerable position at the end of the arm, where they are very prone to getting knocked. Broken balance staff pivots were a common occurrence in early wristwatches and every watch repairer kept extensive stocks of spare balance staffs. Today the situation is different: broken balance staffs are rare and most watch repairers cannot or will not replace a balance staff.

The picture here shows a cross section through the balance assembly of a watch. The gold coloured item is the balance, the thing you see oscillating backwards and forwards as the watch runs. The green coloured item is the shaft on which the balance turns, called the "balance staff". The red items are four "jewels" that provide hard and low friction surfaces for the staff to turn on. The two jewels that the pivots of the staff pass through are called jewel bearings or "jewel holes", and the two that the ends of the staff bear on are called "end stones" or "cap jewels". The pivots of the balance staff, the reduced diameter portions at the ends, are made very small in diameter, just a few hundredths of a millimetre, in order to minimise friction, and are hardened to minimise wear. They are therefore very delicate and dropping a watch or knocking it against a hard surface can cause them to break.

Many shock protection system were devised to overcome this problem. Around 1790 Abraham Louis Breguet invented a spring suspension for the end jewels of the balance staffs of his watches, which he called the "pare-chute" or parachute. But the first commercial and widely used shock protection system was Incabloc, invented in the 1930s by Fritz Marti.

Most modern watches, watches made after WW2, have built in shock protection like Incabloc and will withstand being dropped. But watches made before WW2 do not usually have built in shock protection. You have to be the shock protection for these watches, make sure that they are not knocked hard, dropped or otherwise given sharp shocks.

In the days when all watches were mechanical and before shock protection came along, all watchmakers kept stocks of replacement balance staffs and would change a broken staff cheaply. Today, because it is done so rarely, replacing a balance staff can be very expensive.

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When Buying a Watch

If you buy a watch without a warranty that it has been recently cleaned and oiled, you should get it serviced. If you run it you risk causing wear such that when the watch eventually does stop, as it inevitably will, it is impossible or uneconomic to repair. Read the section on this page about what servicing a mechanical watch entails, and why it is important.

Any watch purchased without a guarantee that it is water resistant should be treated as if it is not water resistant, simply on the precautionary principle.

Be very careful of watches that are not going. If the vendor says that the problem will be easy to fix, ask him how he knows this, and why he hasn't had it fixed; watches that are going sell for more than watches that are not. If it is not worth him fixing the problem, this might be because it would cost more than the watch is worth.

Caveat emptor means "let the buyer beware" and if you are the buyer it is in your interest to be very aware. The remarks below about why a watch described as being “over wound” might actually have stopped apply equally well to any watch that is not running.

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“Over Wound” ? ? ?

One very common description is that a watch is not going because it has been “over wound”. This description is used when the watch crown can't be turned. However, being unable to turn the crown doesn't mean that the watch has been wound too much.

Don't believe stories like this; that being “over wound” is some sort of fault, or that a watch won't go because it has been fully wound.

The reason that the crown won't turn is because the mainspring is fully wound. But saying that this is the reason that the watch doesn't run is nonsense. It is like saying that a car won't start because the petrol tank is full.

Just like a car with a full tank of petrol that won't start, the reason a fully wound watch won't go is because there is something wrong with it. This might be something simple that is easy to fix, and it might be something serious that could be very expensive, or even impossible, to fix.

It is really quite difficult to damage a watch by winding it – unless you have a grip like a vice, muscles like a gorilla, and no sense of feeling. Watches are built to be worn by normal human beings. You can't actually stop a watch by “over winding” it, although if you keep trying to turn the crown when the watch is fully wound this can cause the balance to swing too far and might cause damage.

To wind a watch manually, turning the crown in the clockwise direction winds the spring, turning it anticlockwise does nothing. There is a ratchet in the keyless mechanism that allows the crown to turn in the anticlockwise direction which makes winding easier; you don't have to release the crown and re-grip it at each turn. You should be able to feel that the crown turns in the anticlockwise direction more easily, and feel and hear the little clicks as the ratchet works. When you feel that the crown stops turning in the winding direction as easily, the spring is fully wound so just let go. Do not keep pressure on the crown when the mainspring is fully wound.

If you have had a watch for a few years and it doesn't wind easily, varies in its timekeeping or stops unexpectedly, then it most likely needs a service. All mechanical watches need a service every few years to clean out old gummed up oil and replace it with fresh. You wouldn't run a car for years without changing the oil, would you?

If you are thinking about buying a watch and the seller describes it as over wound, then you need to be extremely cautious. It is possible that the seller might actually believe that this is the problem, or they might be trying to hide the fact that there is something seriously wrong with the watch; caveat emptor, buyer beware.

If it was your watch and it stopped working, then you would know its history and whether you had done something to it, such as dropped it. But with an unknown watch you don't know what has happened to it in its lifetime. It may be that the watch has not been serviced and the oil has gummed up; a simple service would sort this out fairly cheaply. But it could also be that there is a more severe problem, such as a broken balance staff or some internal wear or damage. This would be more expensive to rectify, quite possibly much more expensive, and sometimes even impossible, to fix – or impossibly expensive.

Once you get to know a bit about watches you will be able to make a judgement on this. If the balance is swinging freely and doesn't wobble on its pivots, and there is no obvious damage, then you can be fairly sure that a service will sort out the problem. But if you are not confident in assessing this, it may be better to pass on until you have more experience.