Timepieces/Education & Repair
Repairing Mechanical Watches, Part 1
Understand the differences between mechanicals and quartz models
Accepting a watch for repair can be an intimidating experience. It can be particularly problematic if the watch is an automatic or other mechanical timepiece and your experience has centered on quartz watches and battery repair.
Mechanical watches are powered by a mainspring rather than a battery. Instead of a quartz crystal oscillator to control the timekeeping accuracy, mechanical watches use a balance wheel as the frequency oscillator (see illustration). This system has been developed by the finest scientific and technical minds for over 400 years.
This complex and delicate functioning can be affected by moisture, dirt, old lubricants, rough handling by owners or errors by incompetent repairers.
Shock is less a concern than it once was. Most watches made in the past 40-50 years are protected against the shock of rapid arm movement or accidental strikes against an object while still on the wrist. But a free-fall to the floor will likely break some of the fine parts inside the mechanism.
Mechanicals are far more durable than quartz watches in other respects. Because of their design, technology and the power of the mainspring, a mechanical watch can endure a certain amount of lint, dirt and aging lubricants that would cause a malfunction in a quartz watch.
However, accumulated contamination in a mechanical watch combines with lubricants and wears out the moving parts. Moisture leaking through deteriorating gaskets causes rust that flakes off into the movement and adds to the problem.
Symphony of Motion
The mechanism of a well-running mechanical watch is a delicately balanced symphony of motion. The circular motion of the gears, transmitting power from the mainspring, is changed to the angular, oscillating motion of the balance wheel, resulting in a constant oscillating time/frequency standard.
The biggest threat to the proper servicing of this mechanism is errors by watch repair specialists who dont understand the science involved and dont have the skills necessary to do the proper repairs and fine adjustments. In next months issue, well examine how to avoid these concerns with proper take-in procedures for mechanical watches.
By David A. Christianson, Certified Master Watchmaker
David Christianson is fourth-generation owner of Christianson Jewelry, Kendallville, IN. He is past president of the American Watchmakers-Clockmakers Institute, a certified master watchmaker and a fellow of the British Horological Society. He discusses watch repair for the sales staff in this column each month. Send questions, suggestions and comments to Professional Jeweler, 1500 Walnut St., Suite 1200, Philadelphia, PA 19102; email@example.com.