Corydon Clock - The Blog

By Bud Fisher
February 1947

Cleaning a clock is frequently the only repair required to restore it to service. It is a simple process, as you may find out for yourself by practicing on your alarm clock the next time it stops.

If, for example, you have one of the popular large alarm clocks, first loosen the three small screws at the back near the rim, and twist the movement in a clockwise direction until the screws slip through the enlarged portion of the slots. Next, remove the two winding keys and the four slotted nuts on the back, and slip the movement from this part of the case. Slip a pair of diagonal cutting pliers under the minute hand and pry it off. Then remove the other two hands in the same way.

The dial is removed by straightening the ends of the four lugs that pass through holes in the frame of the movement. Now pull out the small brass wedge that holds the end of the hairspring on the balancing whell, and turn the wheel until the end of the spring slips out of the slot, and also out of the slot in the regulator lever. Loosen one screw at either end fo the balance-wheel staff until it can be removed.

Dissolve some mild white soap chips in water, add ammonia, and suspend the movement in the solution from a wire for about five minutes. Then rinse it thoroughly in gasoline. Brushing with a small paintbrush will remove any remaining dirt. The balance wheel should be cleaned in the same manner, but be very careful not to bend the hairspring. It is a good idea to dry off the gasoline with a fan, or by placing the movement in the sunshine.

If the points of the balance wheel pivots are dull or rounded off, they should be sharpened. The shaft can be placed in a chuck, if a small lathe is available, and the pivots ground to a fine point with an oilstone. An alternative method is to place the balance staff in a pin vise and rotate it with one hand while grinding with the stone in the other hand. A small slot can be filed at the edge of a bench, and the end of the shaft rotated in the slot, with enough of the point protruding to grind. It is also well to clean out the depressions in the two screws in which the pivots rotate.

To reassemble the parts, first replace the balance wheel, making sure that the pin on the wheel slips into the slot in the lever. Then thread the end of the hairspring through the slot in the regulator lever and through the slot where it is clamped with the small brass wedge. Before clamping the end of the spring, hold the wheel so that the pin and the slot are in a straight line with the balance-wheel shaft and the lever shaft. Allow the spring to move freely, and then clamp at this position. If the clock does not tick evenly, the end of this spring should be moved a very little in either direction until it does.

A few drops of light machine oil should be placed on the mainspring and on the alarm spring, and a small drop of very light oil, preferably clock oil, on each bearing. Also put a drop on the balance-wheel pin, and a drop on each arm of the escapement. Use a piece of wire, about No. 22, for applying the oil to the bearings. Now the other parts may be assembled in the reverse order from which they were taken apart.

In order to get the alarm set at the correct position, put on the alarm-set hand first. Then turn the minute-hand set knob on the back in the backward direction until the alarm-set hand begins to turn backward. Turn until it is at some convenient position, such as three o’clock; then put on the hour and minute hands at the three o’clock position. The clock now can be placed in the case and will be ready for use.