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 particular example has thin, original mainsprings.

Time Mainspring: 3/4 x 0.0167 inch.

Strike mainspring: 3/4 x 0.0163 inch. (Unfortunately, I had to replace the strike mainspring because it had a rough action when nearly wound, typical of springs that may break soon. I used a new Merritt’s Antiques P-1956).

Many examples of the No. 89 movement have thicker springs, quite often around 0.0175 inch thick, sometimes thicker. After proper repair, this movement will run well with thin springs.

Here is a video of the escapement motion, first run down 6 1/2 days, then fully wound:

Repair Job. 4970.

This beautiful mahogany Adamantine clock came into my shop recently with a broken time mainspring. Nothing too exciting about that, but I think this clock is so nice looking that I decided to show it here. I had previously repaired it 11 years ago, overhauling the movement and polishing the case and bezel.

I replaced the broken time mainspring with a Merritt’s P-1956 3/4 by .0165 by 96 inches (the original spring was 0.0172 inch thick). The pendulum takes a superb motion (almost too good) and so an even thinner mainspring would work. During my previous overhaul, I replaced the way too strong strike mainspring (an incorrect replacement) with a spring about 0.016 inch thick.

Repair job 4981.

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.

The original mainsprings seemed too strong. The time spring was 0.0182 inch thick, and the strike spring was 0.0178 inch thick. I replaced both with thinner mainsprings, Merritt’s Antiques P-1956, 0.0165 inch thick, to reduce future wear to the mainwheel teeth. The escapement takes an excellent motion.

Repair job 4949.

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.

Time mainspring: The original time mainspring was broken, and measured 3/4 inch wide by 0.018 inch thick. The replacement is 3/4 by 0.0165 by 96 inches, Merritt’s P-1956.

Strike mainspring: The movement came into the shop with a 3/4 by 0.0142 inch mainspring! It may have been original, but it had a jerky action after cleaning and lubrication. The replacement spring is 3/4 x 0.0155 inch thick (Merritt’s P-1496 in the orange and red box).

The video below shows the escapement action when the time mainspring is run down 7 1/2 days and then fully wound. The motion is sufficient but not excessive.

Repair job 4926.

The first video below shows how good the escapement motion is with the thin time mainspring. It is run down 9 days in the video. The second video shows the entire movement in the case and then a closer view of the clock striking the hour and half-hour.

Repair job 4899.