Seth Thomas 18s T&M Special Pocket Watch Repair and Service

Balance Staff Repair and Restoration of an Antique American Pocket Watch

Introduction

If you own an antique pocket watch in need of repair or restoration, feel free to contact me to discuss your watch, or visit getting started. Each timepiece is individually evaluated to determine the most appropriate repair and preservation approach.

This case study documents the service and repair of an antique Seth Thomas 18 Size Lever-Set Pocket Watch. This large American pocket watch arrived after being dropped, resulting in damage to several critical components of the movement, case, and dial. Despite the damage, the watch remained a good candidate for restoration due to the overall condition of the movement and originality of the piece.

Damage from Impact

This Seth Thomas pocket watch had clearly suffered a fall, resulting in multiple issues throughout the watch:

• The balance staff pivots were broken
• The seconds hand pivot was bent and required careful straightening
• The dial feet were bent, causing the dial to shift out of position

Damage of this type is common when heavy antique pocket watches are dropped, as the balance staff pivots are among the most delicate components in the movement.

Balance Staff Fabrication and Repair

One of the most significant repairs involved replacing the broken balance staff. New old stock balance staffs are difficult to find for Seth Thomas pocket watch movements, so a new balance staff was turned on the watchmaker’s lathe and fitted to the movement.

This process included:

• Machining and fitting a replacement balance staff
• Verifying proper pivot dimensions and endshake
• Reinstalling and truing the balance wheel

The bent seconds-hand pivot was also carefully corrected to restore proper hand clearance and operation.

Dial and Crystal Restoration

The bent dial feet were straightened and adjusted to properly reposition the dial within the case. In addition, a new glass crystal was custom fitted to restore both protection and original appearance.

Custom fitting glass crystals is often necessary on antique pocket watches, as many original dimensions are no longer commercially available.

Full Service Procedure

In addition to the repairs above, the movement underwent:

• Complete disassembly and inspection
• Ultrasonic cleaning of all components
• Polishing and inspection of pivots and jewels
• Proper lubrication using modern synthetic oils
• Reassembly and regulation for reliable timekeeping

Despite the impact damage, the watch was otherwise in very good condition and is expected to perform well after service and repairs are completed.

Conclusion

Antique Seth Thomas pocket watches remain an important part of American horological history. Careful restoration of damaged examples helps preserve both their mechanical function and historical character.

For additional information on watches we work on please visit these pages:  Vintage Rolex repair— Vintage Breitling repair —Vintage Omega repair — Vintage Heuer repair —Bulova Repair, and Pocket Watch Repair. See my FAQ for additional information, and visit Watch Repair Case Studies.

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Brief History of Seth Thomas Pocket Watches

Seth Thomas Clock Company was one of the best-known American clock manufacturers of the 19th century. Although primarily recognized for clocks, the company also produced pocket watches during the late 1800s and early 1900s.

Large 18-size lever-set pocket watches such as this one were designed for reliability and ease of use. Lever-setting mechanisms were commonly used on railroad and higher-grade watches because they reduced the risk of accidental time changes when winding or handling the watch.

These watches are appreciated today for their substantial construction, traditional American movement design, and historical significance.