This example looks similar to that in the photo labeled “1924″ in Tran Duy Ly’s Seth Thomas clock book. The case is dark mahogany, 31 inches tall, 15 5/8 inches wide, and the dial has a 10 3/4 inch time track. The movement is 8-day time only, no. 123 E. I first overhauled this clock in 1999 (polished pivots and installed 5 bushings). It ran until 2009, when the click broke (an uncommon occurrence).

I cleaned the movement and did the following repairs:

• Installed a new click;
• Installed a new mainspring, as the old one had a squeaky action even after cleaning and oiling. I installed a Merritt’s P-1956 3/4 x 0.0165 x 96 inch mainspring (the new spring opened up to 5 1/4 inch diameter after being wound and unwound 5 times).
• The pivots, which I had polished during the last overhaul, were still in excellent condition.

This movement has stopworks for the mainspring, I set it up so that it stops the winding when the spring is one turn from being fully wound. The case has a beat plate, and the motion of the pendulum measured on the plate is as follows:

• Escape arc:  + and – 0.75 degrees
• Wound up: + and – 3.3 degrees
• Rundown 3 days: + and – 3.2 degrees
• Rundown 7 days: + and – 2.8 degrees

The paint on the dial was flaking badly, and the customer wanted it restored. I had it repainted by The Dial House in Dallas, Georgia.

Here is a slide show of the clock and its movement:

Repair job 1891.

This example has an 8-day time only movement driven by two mainsprings. The mainsprings are the original thick, roughly finished springs. They are in good condition and provide plenty of power to operate the clock. They are narrower than standard 8-day mainsprings, only 3/8 inch wide. They are quite thick, 0.022 inch.

The escapement is a club tooth deadbeat (or semi-deadbeat, as there is slight recoil during locking). The escapement was patented by B. B. Lewis on August 31, 1870, patent number 106,843.

The dial on this example was repainted by The Dial House, Dallas, Georgia. The second hand is a replacement.

Besides cleaning, the movement needed the following repairs:

• Tighten the click rivets;
• Polish pivots;
• Install 7 bushings;
• Replace one bent pinion wire in the second pinion;
• Replace the pinion wires in the escape wheel;
• Increase the hand set tension.

Here is a video of the escapement:

Here is a video of the case:

Here is a slide show of the clock and movement:

Repair job 5023.

Historical reference: NAWCC Bulletin Supplement Number 12, February 1978, “The Welch, Spring and Company”, by Owen H. Burt and Jo Burt.

Before repair, the clock would run for several minutes and then stop. While running, it would go in and out of beat (the ticking would sometimes be even and sometimes uneven).

The movement was taken apart and cleaned. The major problem was that some of the escape wheel teeth were non-uniform. I used the Webster escape wheel tooth straightener to ensure that all the teeth were at the same angle. The wheel was mounted in the lathe and the teeth bought to a uniform height, then the burrs were removed. The pallets were polished, the worn pinion wires in the escape wheel pinion were replaced, the pivots polished, and bushings installed in the worn pivot holes.

The following video shows the escapement action before and after repair:

The following video shows the movement in the case and shows the hour striking:

It is possible that the movement is not original to the case. We suspect this for two reasons:

• The pendulum bob is quite low in the case;
• The end of the center arbor touches the glass when the door is closed.

The movement is labeled “Plymouth” which means that it was made in 1865 or earlier when the town where Seth Thomas was located had the name “Plymouth Hollow”. It 1865 the town name was changed to Thomaston to honor Mr. Thomas. The case label says “Thomaston” so this could be a transition clock made around 1865, or it could be a later case with a older movement. The reverse painted glass is not original to the case, it appears to be a New Haven multicolored glass.

The weights are replacements, weighing as follows:

• Time weight: 8 pounds 1 ounce
• Strike weight: 6 pounds 9 ounces

Repair job 5064.

The clock had its original mainsprings, both of which were marked “W. Barnes Patented Nov. 27, 1866″. The strike spring was quite thick (0.02 inch). Both springs were stiff and very hard to remove from the mainwheels. I installed new Merritt’s P-1956 mainsprings that are 3/4 by .0165 by 96 inches. They provide a good escapement action and striking speed. Gilbert clocks of this type take a large pendulum swing with a small amount of supplementary arc (overswing) due to the design of the recoil escapement. I slanted the back of the mainspring arbor hooks to make the mainsprings easier to remove for future cleaning.

The video below shows the escapement action with clock fully wound and then run down 8 1/2 days, then shows the movement and then the entire clock.

Repair job 4957.

The mainsprings appear to be original (they match in color and style and look old).

Time mainspring: 3/4 inch wide by 0.0172 inch thick. This spring provides sufficient power, as the escapement motion is excellent.

Strike mainspring: 3/4 inch wide by 0.0142 inches thick. This spring is very thin, yet the striking speed is fine.

I retained both original mainsprings in this clock. They were in good condition, operated smoothly, and provided enough operating power, so there was no reason to change them. A good old mainspring is no more likely to break than a new one. (Some repair shops install new mainsprings in every clock they repair, I disagree with this practice.)

The case is 33 inches tall, and the minute track diameter is 11 inches.

Repair job 4955.

A previous repairer had very badly bushed the front time second wheel pivot hole, and mutilated the pivot and shortened the arbor in the process. I added on to the arbor to restore it its original form, and installed a good bushing.

The time and strike mainsprings were old replacements that were too strong (0.0184 inch thick) made by Usibel, France. I replaced them with Merritt’s P-1956 3/4 by 0.0165 by 96 inch mainsprings.

Here is a video showing the escapement. The motion is excellent, even with the thinner mainspring. The mainspring is unwound about 8 turns (8 days of running) in the video.

Job 4962.

The round 8 day movement is 3 1/4 inches in diameter with open mainsprings. It has rack and snail strike on the hour and half-hour. It has a strip recoil escapement.

I did not do a complete repair job on this movement, per customer request.  I cleaned it and replaced the strike click, which had failed. I also replaced the time mainspring, as the existing one was providing at least twice the necessary torque (it was not original). It was 7/16 x 0.018 by 60 inches, and I replaced it with 3/8 x 0.014 by 60″. A longer and thinner spring would have been even better, but not readily available.

The original strike spring is only 0.0125″ thick and is 7/16 inch wide, and 8 feet long. The original time mainspring was probably similar.

Here are movies of the rack and snail strike mechanism and the escapement.

Here is a slideshow.

Repair job 4990.

The escape wheel had two teeth that were too short due to damage by a previous repairer. The slide show below shows that the damaged teeth were removed, a brass plug inserted, and then 2 teeth filed to shape.

Both mainsprings were original Seth Thomas springs, one .0177 inch thick and the other .0165 inch thick. I don’t know for sure which one was originally on which side (time or strike). The .0177 inch thick spring was too strong. The thinner spring did not unwind smoothly. I replaced both with Merritt’s P-1956 springs 3/4 inch wide x 0.0165 inch thick x 96 inches long.

One thing strange about the case is that one end is mahogany Adamantine, but the other end is black! (see slide show below). It appears to have been made this way.

Repair job 4830

One of my Chauncey Jerome 30 hour OG clocks was missing its weights when I bought it, and so I experimented with weights. I found that the time train of the clock would run reliably on 1 pound! (Normally these clocks have about 3 to 3.5 pounds on the time side). The strike weight usually weighs around 2.5 to 3 pounds.

I recently repaired an early Seth Thomas 30 hour Ogee. The weights that were with the clock when I received it are 2 pounds 9 ounces and 2 pounds 10 ounces. They look old and match each other in appearance, but there is no way to know if they are original to the clock. The strike sounds fine with this amount of weight, and the pendulum and escapement take an excellent motion. Here is a video showing the escapement in operation. Note the generous amount of overswing or supplementary arc (how much further the verge moves after an escape wheel tooth lands on one of the pallets):

This clock will run for a short time with a 7 ounce weight on the time side, with almost no overswing. There is noticeable overswing with 9.8 ounces of weight, and with 1 pound weight the overswing is small, but enough. With 1 pound, 12 ounces, the overswing is quite good. Of course, a clock movement must be in excellent condition to run with this little weight.

The striking sounds a little slow, but acceptable, with 1 pound 12 ounces of weight. The striking will run with 1 pound of weight, but it sounds WAY too slow.

I plan to wind this clock daily (it is on a workbench at my clock shop), and will run it with a 1 pound time weight and a 1 pound 12 ounce strike weight, to reduce wear in the movement.

Update

From June  30, 2009 to February 10, 2010, it ran continuously on the 9.8 ounce time weight. Then, it would occasionally stop around 10 minutes before the hour (when the strike levers are lifting). On February 13, I started running the clock with a 15.6 ounce (440 gram) weight.

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:

Here is a slide show:

Repair job 4819.