Dismantling and Reassembly

These instructions are limited to operations that can be done with the minimum of tools: a selection of jeweller's screwdrivers and some watchmaker's pliers. It is best to have three of the latter – one with fairly blunt jaws for picking up small parts, one with very long slender points for probing into otherwise inaccessible areas, and one with sharp but relatively short points which will exert a good grip but can also manoeuvre in tight places. Most people will also need a loupe (a simplified low-power microscope that can be gripped in the eye-socket, leaving both hands free).

These are all operations that I have successfully done myself. This means that they are very elementary and do not in any way replace the more refined techniques described by writers such as Britten and de Carle. Similarly, I do not touch on the making of new parts, since this is beyond my own resources. Despite these restrictions, I hope that these pages will bring a certain level of watch work within the grasp of people who may have regarded it as an inaccessible mystery.

1 If the watch is pair-cased, remove the outer case by pressing the release button (usually at 3 o'clock). On a single (consular) case, open the glass (crystal) by levering with a finger-nail under the lip which will be found between 1 and 2 o'clock; the glass need not be removed.

2 Position the watch with the movement hinge (normally at 12 o'clock) towards you.

3 With a suitable tool (sharp-nosed pliers, or an opened-out paper-clip will serve), push against the right-hand end of the brass pin which passes through the hinge; this pin is tapered and will move only in one direction. Once started, the pin can be pulled out with pliers from the other end.

4 If the glass shares its hinge with the movement (as in most pair-cases), lever it off and put it aside. Then release the movement from the case by engaging a finger-nail in the transverse slot of the steel clip at 6 o'clock and pushing the clip inwards. Lift the movement out of the case.

1 Remove the movement from the case (section A). If there is a dust-cap, leave it in place for the moment.

2 Beginning with the minute-hand, remove the hands by gently levering under the central boss with the points of a pair of long-nosed pliers (there are also special tools for removing hands, but it is not difficult to manage without them). Never apply even the lightest force to the shaft of a hand as it will bend very easily. For the second-hand, you may need a thin knife-blade to get under it.

3 Remove the dust-cap, if present; push the curved blue steel catch clockwise as far as it will go and lift the cap away (fig. 1). Turn the movement dial-downwards. Find the three dial-feet, each of which extends through the front plate near one of the pillars. Each foot should have a brass pin passing through it (although one or two may well be missing). Pull out these pins with pliers. If a pin is difficult to start, you can carefully push outwards against its inner end with a screwdriver blade, using something - a pad of cotton-wool or a lump of Plasticine, perhaps - to prevent the pin from flying away across the room when it does give way.

4 Turn the watch back over so that the dial is upwards. Lift off the dial. If it is reluctant to come away, do not lever it at any one point on its edge - this is likely to cause a hairline crack - but run a thin blade round between dial and front plate so that the dial is released evenly and gradually.

5 With the dial removed, lift off the two motion-wheels (fig. 2); they are not fixed in any way and are sure to drop off and lose themselves on the floor if not safely removed at this point. If the set-up wheel is not held by the tension of the mainspring (i.e. if the fusee-chain or the spring itself is broken), this wheel too should be removed.

1 Remove the movement from the case (section A).

2 Remove the dust-cap and look to see if a set-up wheel and pawl, like those shown in figure 2 above, are visible on the barrel bridge. If so, go straight to step 3. More often, however, the set-up assembly is hidden behind the dial, which must be removed (section B).

3 [This section will not apply if the chain is broken; you can take off the set-up wheel (if it is still present) and then go straight to step 4.] Release any tension in the mainspring. There are two ways of doing this: -

(a) (Preferred method) Remove the dial and motion wheels (section B). Immobilise the winding-square, where it projects through the back-plate, by holding it in a pin-vice or clamping a small locking-wrench on it; in the latter case, line the jaws of the wrench with a bit of cloth to prevent it from scratching the square. Now turn the movement front-plate upwards and hold it firmly in your left hand, taking care not to press on any of the wheels. At the same time, loosen the two screws holding the L-shaped bridge which locates the third wheel (visible in fig. 2). Remove this bridge and, keeping a firm hold with the left hand, draw out the third wheel. This will release the barrel/fusee assembly from the locking effect of the escapement and it will try to run; however, the pin-vice or locking pliers will prevent this and instead it will be the body of the movement that revolves. The purpose of the left-hand grip is to restrain this action so that the tension of the mainspring is released at a safe and controlled speed. Carefully let the movement slip through your fingers until all tension is gone and the fusee-chain becomes slack.

(b) Hold the movement in your left hand (or fix it in a vice) with the set-up wheel facing upwards. With the forefinger of the left hand, turn the spring-barrel towards the fusee-cone so as to introduce some slack into the chain. Still holding the barrel in this position, use the other hand to insert a screwdriver blade between the set-up pawl and the wheel and push the pawl outward until it disengages from the wheel. The barrel will suddenly stop resisting the pressure of your forefinger and the chain will fall slack. The drawback of this method is that the release of the spring tension is very sudden and may possibly jar the spring off its spindle; however, I have used it many times without ill effects. Unlike (a), it does not involve meddling with the train.

The set-up wheel can now be removed from its squared arbor and put away safely.

4 The chain must now be unwound from the fusee-cone. Generally you will find that almost all the chain is wound onto the cone, so that you need to begin at the narrowest (and most inaccessible) part of the cone, just under the back-plate. Having positioned the movement with the back-plate uppermost and the barrel and cone edge-on towards you, you need to pull the chain towards the right; sometimes this can be done by gripping it with a very slim pair of pliers, but more usually there is not enough clearance and you will need to drag at the chain with a thin pointed tool (a craft-knife blade, perhaps, or your smallest screwdriver) (Fig. 3). The chain will tend to drag the cone round with it, but if you concentrate on freeing just a few links at a time you will soon have a half-turn clear. Work the tool round the back of the cone as far as you can reach to push as much as possible of the chain out of its channel before returning to the nearer side and starting on the next turn. This can be a frustrating job, but it is guaranteed to grow easier as it progresses. — Check frequently that the free length of the chain hangs clear of the side of the movement and cannot catch itself among the train-wheels. — When almost all the chain is free, rotate the cone with the winding-key until you expose the slot into which the chain hooks. Use long-nosed pliers to grip the chain as near the hook as possible, and carefully work it towards the right until the hook disengages from its brass post within the slot and the whole chain can be drawn clear.

1 With the old chain removed, take a piece of white cotton thread at least a foot long and attach it to the fusee-cone at the slot for the hook. If you are lucky you may be able to feed the thread behind the tiny brass pillar within the slot and tie it there; failing this, wedge it into the slot with something fairly soft that will not damage the fragile brasswork of the cone, such as a sliver of matchstick.

2 Turn the winding-square with a key to draw the thread onto the cone, holding it taut and ensuring that it stays in the channel. When the thread has filled the channel from bottom to top, lay its outer end against the spring-barrel so as to go about a quarter-turn round it. Cut off the thread at the point thus reached and unwind the thread from the cone. It should give you a serviceable template for the length of chain needed.

If this procedure cannot be applied for any reason - e.g. because access to the cone is restricted because of the way the movement is designed - then you will be dependent on trial and error to find the right chain. As a rough guide, the length of a 19th-century chain will be about 4.5 times the diameter of the movement.

1 Turn the fusee-cone so that the slot for the hook faces outward. Ideally it should be just to the right of centre.

2 Position the movement with its edge towards you, the spring-barrel nearest, and the back-plate uppermost. Find the end of the chain which has a spike projecting from its hook and fit this hook into the small hole on the barrel. (There is often a larger rectangular hole near the rivet which marks the outer end of the spring; this is not the one to use.) Lightly press your left forefinger on the hook to hold it in place.

3 Start turning the barrel itself to the left, keeping your forefinger on the chain to guide it straight and ensure that the hook does not slip out of its hole. As you go, frequently check that the chain has not acquired any kinks or loops, and that the part of it which you have wound onto the barrel does not cross over itself or stray too near the lower edge of the barrel. A screwdriver will be found useful to prod the barrel along, so that the two hands do not get in each other's way.

4 As the free end of the chain draws near to the slot in the cone, make sure that the chain is in line with the slot. When the hook at this end is about 1/8" to the right of the small pillar within the slot, use a screwdriver or pliers to coax the hook into the slot. Push it well in. Now resume turning the barrel until the chain is taut. Wedge a piece of card between the barrel and one of the plates to keep the chain firmly in place.

5 Fit the set-up wheel to its squared arbor. Note that it must be fitted the right way round; the angled teeth point to the right if it is in the usual under-dial location, or to the left if it lives on the barrel-bridge. Push the pawl into engagement with the teeth. While holding the pawl firmly in place with the left forefinger, use a screwdriver held in the right hand to push the wheel round anti-clockwise (under-dial type) or clockwise (barrel-bridge type) until you feel a strong resistance from the mainspring (see animation above, fig. 4). You have now reached the point where the tension of the spring will keep the chain tight, so that the wedge can be removed from under the barrel.

6 If possible, turn the set-up wheel a few more notches - keeping up the pressure on the pawl so that it re-engages with the teeth as soon as possible - until the watch will run for a minute or so without any actual winding. Do not be greedy, though; if the pawl fails to catch the teeth at any stage, the wheel will fly back to its starting-point and the chain may slip off the barrel, forcing you to detach it and start again!