Some watches carry their history on the outside; this one carried it on the inside. A Lemania 5012 chronograph, military-issued to the South African Air Force, arrived at our Seattle workshop for a full service — its inner caseback engraved "AF 12189." A pilot's instrument, built to be read at a glance and trusted under load.

The dial, case, and inner caseback — engraved "AF 12189," marking its Air Force issue.

A serial tag worth protecting

As we disassembled the movement, we noticed the serial tag on the three-quarter bridge was showing early signs of detaching. It was still in good condition, and we intended to keep it that way: rather than send that bridge through the ultrasonic cleaner, we hand-washed it to avoid disturbing the tag. Small decisions like this are how original details survive a service.

The three-quarter bridge, stamped "5012," with its delicate serial tag.

Burrs in the calendar works

A small intermediate pinion in the calendar setting had developed burrs, and those burrs had scored both the mainplate and the yoke the pinion rides against. Left alone, that scoring only deepens. We burnished the burrs and gouges smooth to arrest the wear and protect the surrounding parts.

The calendar setting works, where a burred pinion had scored the mainplate and yoke.

Resetting the escapement

The shellac securing one of the pallet stones was chipped. We cleaned the old shellac from the pallet fork and applied fresh shellac to resecure the stones — the tiny, heat-set bond that keeps the escapement honest. A loose brass head on the mainspring-barrel arbor was also re-riveted while we were in there.

The pallet fork with its stones reset in fresh shellac.

A stop, a diagnosis, and a fix

With the movement cleaned, rebuilt, and freshly oiled, we set it running on the timer — and overnight, it stopped. Rather than guess, we tore it back down, investigated, made adjustments, and re-cleaned. This time it ran well for over 24 hours, and we continued the build with confidence.

Back on the timegrapher after the fix — running steadily again.

Cased and tested

The case was ultrasonically cleaned, the refinished dial and hands refitted, and the chronograph cased up. It then entered a ten-day timekeeping and quality-control test, passing timing, power reserve, and QC before heading home.

The finished Lemania SAAF chronograph, serviced and cased.

This is the kind of work we do every day: complete, documented vintage watch restoration on mechanical watches and Accutrons of every make. If you have a military or vintage chronograph in need of service, start an intake and tell us about it.