This chapters deals with disassembly of the mainspring barrel and mainspring cleaning and lubrication.
Before you undertake disassembly of the mainspring barrel note the following:
- If you are working on a brand new watch then your mainspring is FINE and
it does not need re-lubrication. Therefore information provided here is for educational purposes only
and you are NOT required to do any disassembly.
- If you are working on a 5-10 year old watch then you have two options:
to replace the barrel completely (recommended by Seiko) or to clean and lubricate the existing mainspring.
Should you opt for the latter, follow the instructions in this chapter.
- If you are working on a 20+ years old watch then it is strongly recommended to replace
both barrel and mainspring. Unfortunately, for some Seiko calibres, spare parts are no longer available
so you should at least clean and re-lubricate the existing mainspring.
Information provided here will enable you to do the job properly.
Clean and properly lubricated main spring is the key to a movement's overall performance.
Gummed-up and dry spring, worn barrel and barrel cover are main reasons
for lack of power reserve, poor auto-winding and poor amplitude of balance wheel.
Therefore it is absolutely essential to clean and lubricate the mainspring as part of a general overhaul.
In the case of a Seiko Cal 7S26, new mainsprings are lubricated with a mix of grease and graphite powder.
As watch repairers have found, such mixture allows adequate lubrication for many years.
Unfortunately, original Seiko S4 lubricants are not easy to source and it is very messy to apply.
A good alternative is Swiss-made lubricant Moebius 8200 (or 8141).
However, at the end of the day, the point is not necessarily in the type of lubricant
but how it is applied. Too much lubrication is not only unnecessary, but will cause unwanted effects
to the overall performance. The trick is to apply lubrication in a very fine film on both sides
of the mainspring, over it's entire length and to lubricate inside the barrel wall as well.
Unlike wheels and bridges, a mainspring should NOT be cleaned with benzene or alcohol based
cleaning solution. Proper cleaning consists of removal of old grease and dirt
and it is best done with paper tissue or fine cloth.
IMPORTANT: do not bend or kink the mainspring. Bent mainspring will not perform as designed!
Also avoid putting too much pressure on the beginning of the spring (coiled area in the centre of the barrel).
The shape of the curved end is designed to allow the spring to "hook" onto the barrel tightly.
Use 'the gum' to clean fingerprints and excess lubricant.
