| Oils. |
Any mechanical device needs to lubricated to ensure correct efficient operation. This is especially important with a watch movement. The power generated by a standard mainspring is considerable, equivalent to that of foot pump. The power has to be transmitted to the escapement in a smooth flow, if this is not achieved the timekeeping will be compromised. Lubrication is the key to this.
On finer watches some of the train wheels turn in self contained oil traps, for this explanation we will concentrate on a standard manual watch.
There are 5 oils required to lubricate a manual watch: -
Mobius 9415
Mobius 9010
Mobius D5
Mobius 8141
PML 8200
Once the movement has been stripped and clean, it is ready for re-assembly.
Just putting the movement back together would serve little purpose.
Next to the mechanical knowledge, and the finer adjustments, oiling is one of the watchmakers hidden arts.
The mainspring is housed in a barrel, this must turn freely on its arbor, and the arbor turn freely between the bridge and main plate. The oil used for this is 8141, a heavy oil. The same oil is used on the centre wheel pivots, this wheel can be said to take the brunt of the force of the spring, therefore it must be lubricated heavily, this oil is also used on the 3rd wheel.
The 4th and escape wheel pivots are lubricated with 9010. The pressure on these wheels is a lot less, too heavy an oil at this stage would cause drag.
This moves us onto the escapement and balance assembly.
The face of the pallet stones are lubricated with 9415. This is a light grease to allow the escape wheel teeth to pass between the stones easily. A grease may sound drastic, but in watchmaking, the grease is very fine. A grease is basically a lubricant suspended in a gel.
The pallet pivots are not oiled, although they are constantly moving the pressure on them is negligible. Oiling them would again cause drag, at this delicate stage of the watch, this would be fatal.
The balance wheel pivots run in a shock resisting assembly designed to absorb any accidental damage caused by the wearer. It also acts as an oil trap.
The jewel hole is a steel cup with a jewel pressed into it, the hole is large enough to accept the pivot and allow it to turn freely, its face is convexed.The endstone fits into the rim of the jewel hole, its face is flat.
The oil used at this point is 9010 and holds the two pieces together by capillary action. When viewed from above, the oil forms a circle, its size should ideally be 2/3rds of the diameter.
Oiling is also important on the dial side of the movement. All of the pivots are oiled as before.
The handset, winding and motion work must now be oiled. Most of this is oiled using 8141. However there are some components which require heavier lubrication.
The winding work generates a lot of pressure, consequently 8200 grease is used.
The return bar, setting lever, stem, clutch wheel and winding pinion must be greased to ensure correct operation. The clutch wheel and winding pinion have beveled teeth, to allow them to run backwards against each other. {backwind}. Consequently they must move up and down the stem. If they are not greased correctly, they will bind and the normal back and forth winding operation will not happen.
The setting lever and spring must be greased to allow the handset function to operate.
Finally the canon pinion is greased, again to allow the hands to be set. The canon is a friction fit onto the centre wheel. In normal use the wheel carries it, but when the handset is engaged it must be able to turn to adjust the time.
The movement is now lubricated.If the other adjustments have been completed, the watch should run correctly.
Oil generally lasts for about 2/3 years before it starts to break down. When this happens, friction is increased and the watch will begin to behave erratically.
Time for another service.
Please note: This is not an exact description of the actual oiling procedure.
We have tried to make this accessible to the reader as possible.
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