TYPICAL REPAIR PROCESSES

1. EXAMINE AND DOCUMENT:

These days it involves taking digital photos, but back in 1993 it was necessary to make a detailed sketch. Sometimes the fault is evident, such as a broken main spring, but it can also just be the accumulation of dirt, corrosion and rust that is causing the problem.

2. DISMANTLE:

Safety is a consideration at this point because of the potential energy stored in the spring or springs. First, this energy has to be released using a ‘let-downkey’, which restrains the spring tension. Next, the retaining pawl is disengaged and the spring is allowed to run down in a controlled release of energy. Springs sometimes break during this procedure and hurl missiles out of the works, so it’s wise to always wear safety glasses and gloves for this task.

3. CLEAN:

This involves removing corrosion or rust and cleaning all the parts using a commercial clock-cleaning agent. Next, it’s rinsed with water, dried and polished. Then, if the reason for the stoppage wasn’t found in step 1, the clock is reassembled and tested. If it now runs and keeps time, the job’s done.

4. CLOSE SCRUTINY:

If, however, the clock still won’t run, it’s time to exercise extreme patience. Each tooth in every wheel and pinion in all the wheel trains must be examined for damage. Each arbor bush and bearing surface must be examined for wear, which can cause wheel-tooth misalignment and jamming. The escape mechanism and its springs, levers and latches must also be scrutinised until the fault is found.

5. REPAIR ALL FAULTS:

Now it’s time to replace worn bushes and arbors, insert bushes if the arbor holes in the front or back plates are worn, replace broken springs, or replace worn wheels or broken wheel teeth. This is time-consuming (and meticulous) work.

6. BACK TOGETHER AGAIN:

After reassembling the clock, it’s time to wind the mainspring, or wind all weights to the top (horologists do not call them mass pieces, by the way), set the clock in motion, and then check the ‘beat’. The beat is the ‘tick-tock’ action that must have equal spaces or time between the tick and the tock. A defective clock mechanism will ‘tick---tock-tick---tocktick’, and soon run to a stop again unless the cause is found (the problem will usually be found somewhere in the escapement mechanism).

7. TESTING:

Finally, the clock is tested for several days and the pendulum adjusted each day until it keeps accurate time to within a minute a day.