a watch long time no use
Lot of guys said if a watch wasn't used for a long time,it must be winded at least once each of them think the oil will be dry if not you agree with them?Why?
New synthetic oils
dry up at the same rate whether the watch runs or not. With any mechanical device it is wise to move it internally periodically. New watches actually sit in dealer's cases for years, in many cases, with no issues.
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Hairspring, is still largely made of metal ( except few silicon based ones), however light it might be is still subject to gravitational pull , so if left sitting idle for extended period of time, it can be VERY slightly pulled out of shape and affect acc...