The Broken German Seth-Thomas Clock
Repairing the broken German made Seth-Thomas clock by replacing the movement with a new one. Seth-Thomas went out of the clock business as of about 40 years ago. The movement has lived its long after its life expectancy of 25 years just by having the name ST. The Seth Thomas from WW2 and prior used American movements, but after 1950 used German made units. So they did not make any movements themselves after the 1950 date, instead they were mostly made by Hermle. The Hermle clock movement is alive and well, so the movements are still available.
What happened to the old one
After 25 years the oil becomes a solid instead of a liquid. This will cause too much resistance in the movement for it to run and it will end up a not working. Just having the name Seth Thomas on the clock means it is about 40 years old at best. There are two choices if saving the clock, restore the old movement or get a new one if possible. The choice is an obvious one, the new unit costs a fraction of the price of restoration. It ships today instead of waiting up to 6 months for the restoration to be completed. A new one will last another 30 yrs without much complaint.
After 25-30 years this happens
Why does age effect the operation of the German clock movement? The clock oil that is put on the movement back when it was new, has solidified with age. What was once a lubrication to the Seth Thomas movement has now turned to a sticky black abrasive substance. This creates both resistance and wear on the movement and it ends up broken. This wear and resistance will ultimately stop the clock from functioning properly because the pivots that ride in the holes of the movement's brass plates will not be able to spin as freely as they did in the past. The holes have become oblong instead of round so the pivot is pinched inside of the hole that it's supposed to spin inside of, and the oil is an abrasive rather than a lubricant.
So now you see the choice is pretty clear. The new movement, when available from clockworks.com is the best choice by far. The movement will be the same movement for a fraction of the price, brand new, oiled, tested, and last decades longer than even the best restoration. The broken German made Seth-Thomas clock can be back up and running in a week.