If your clock has stopped working and you think it is “wound too tight”, DON’T TRY TO UNWIND IT! You will just break it worse.
I just received a Schatz 400 day anniversary clock that was made in April 1953. Someone pushed on the “click” (the device that clicks as you wind the mainspring). It unwound with a big bang, and damaged the barrel and broke one of the pivots (the small ends of the gear shafts. This added at least $70 to the repair bill!
In most cases, your clock did not stop because it was “wound too tight.” It stopped because it needs to be taken apart, cleaned, and other necessary repairs made.
DO NOT TRY TO UNWIND YOUR CLOCK! BEING “WOUND TOO TIGHT” IS NOT THE PROBLEM.
I repaired a Schatz standard 400 day clock made in August 1952. The next day, the hour hand did not align correctly with the minute hand. As I turned the minute hand forward, I saw that the hour hand was getting further and further behind. The hour hand was losing 1/4 hour every 12 hours, or one hour every 2 days!
I removed the hands and dial, and counted the number of teeth in the motion work gears. The minute wheel had 49 teeth instead of 48! I remembered reading about this problem years ago in the Horolovar 400 Day Clock Repair Guide (question 15 in the question and answer section). This is the first 400 day clock I’ve had with this problem. It probably baffled its owners, as it would seem to lose 1 hour every 2 days! I’m surprised that this problem wasn’t fixed years ago. The current owner bought it at a flea market and it wasn’t working, so he couldn’t observe the hour hand problem.
To correct the problem, I replaced the minute wheel with one having 48 teeth.
One interesting thing about repairing 400 day clocks, is that they almost NEVER need bushing. The few that have come into my shop with bushings installed by a previous repairer, would have been better off if they had not been bushed (because the bushings were installed off-center and were too tight on the pivots)!
The gears in 400 day clocks turn so slowly that the pivot holes wear very little. A 100 year old 400 day clock that has been running for many years might possibly need a bushing or two, but it is a bad idea to routinely bush 400 day clocks.
Many 1950′s 400 day clocks (especially the Schatz) can benefit by having some of the pivots smoothed and burnished. Take a close look at the pivots after cleaning, and quite often the the second, third and fourth wheel pivots will show slight pitting. Smooth broaching the pivot holes (using an oiled round broach) is also a good idea.
I recently overhauled this Seth Thomas tambour mantel clock with enamel dial. The case is 21 inches long. The movement is No. 89AL, a version of the popular No. 89 movement with solid back plate and active striking on the half hour (as opposed to passing strike).
Both mainsprings are original Seth Thomas springs and are 3/4 inches wide and 0.017 inches thick. They provide plenty of power to operate the movement.
Here is a movie of the clock, showing it operating and striking:
I recently repaired this Kundo miniature 400 day clock with a pretty gold colored metal dial. The movement needed cleaning and a new suspension spring. The pivots and pivot holes were in good condition.
Here is a movie of the escapement in operation:
Here is a slide show showing the complete clock, and the gears in place before the back movement plate was put on:
A recent repair job on a Kundo oval base 400 day clock reminded me that the upper suspension block must fit properly in the saddle.
I cleaned the movement and replaced the suspension spring. It did not need any pivot polishing. After assembly, the clock ran, but the pendulum made a small rotation even when fully wound (about 3/4 of a turn with small overswing or supplementary arc).
The upper suspension block had some play in the direction of rotation of the pendulum, causing energy loss. I closed the slot in the saddle slightly, just enough to remove the play, but still allowing the block to pivot freely about the suspension holding screw. The swing of the pendulum increased to about one full turn. Now I am satisfied that this clock will run well.
1) Early Golden Hour clocks (made around 1953 and 1954) don’t use nylon pads to support the rotating gear ring. Instead, they have three slightly raised metal areas. When these wear down, the friction increases and can cause the clock to be unreliable. On 3-31-08 I repaired one by applying several pieces of black plastic electrical tape near the raised metal areas. Time will tell how long this repair lasts.
2) The same job as above had a groove worn in the metal retaining ring, causing the the gear ring to bind in places. I used abrasive paper to remove the grove. Now the gear ring turns much more smoothly.
