This Waltham pocket watch required a service and crystal replacement. It was running, but not very well at all, timekeeping was out by several minutes a day and the balance wheel had very poor amplitude.
It was approximately 81 years old at the time of writing: Production dated year 1936, according to the Waltham “Gray Book” List.
The watch is in very good condition given its age. It is cased in a gold filled case by British maker Dennison. This particular case is made of a base metal sandwiched between two plates of 0.036mm thick 9 carat gold. It is their “star” grade which at the time was guaranteed for 10 years. The quality of the plating by Dennison has stood the test of time as it is still in good condition, with very little base metal visible.
I really like these old Waltham pocket watches, more often than not they have a lot of decoration on the movement. A real pleasure to look at, and they always feel special to work on.
I start by de-casing the movement and carefully removing the lovely blued steel hands from the dial. The enamel dial also needs a lot of care, as they are prone to cracking, especially when there is already a damaged area like on this one.
I start disassembly with the dial side
There is not a lot to it: hour wheel, minute wheel, cannon pinion. The intermediate wheel is held in place with a screw and a washer.
I can then move onto the other side, starting by removing the ratchet and transmission wheels.
I then remove the barrel bridge and click spring assembly.
As I move on to the train wheel bridge, a significant issue becomes apparent. This picture below is of the fourth wheel bush. As you can see the hole is far too large for the size of the pivot. I actually suspect this was a jewel setting which was added at some point during the life of the watch, and the jewel has gone missing.
The pivot is completely free, the movement will never perform correctly with that amount of side shake and end shake on the fourth wheel.
This movement is 9 jewels, so a jewel here would make it 10. The fourth wheel was clearly meant to be mounted on brass bushing rather than an extra (missing!) jewel. I will get back to that later, for now I carry on with the strip down of the watch.
Years of dirt and grime visible here on the balance wheel jewel (it should be a nice pink/ purple colour)
With the train bridge removed I can start stripping the train wheels.
And this is the movement left with just the balance wheel, and keyless work.
Note the lovely blue Breguet overcoil on the balance. You only find this type of hairsprings on high end watches nowadays.
I also strip the mainspring.
And this is the movement fully disassembled.
I now need to address the issue associated with the rogue bushing. I first pop it out of the bridge.
I take all the necessary measurements – Diameter of the bushing using a Vernier gauge.
And diameter of the the fourth wheel pivot using my pivot gauge.
With these dimensions in hand, I expected it to be straightforward, order the necessary part and complete the project. Unfortunately none of the materials supply houses I normally use have a suitable generic bushing: the diameter of the bushing is either too small to have the correct hole diameter, or the hole diameter is too big to have the correct bushing diameter.
I could use a friction fit jewel, but I would rather return the watch to its intended, 9 jewels design. In the end I decided to make the required part myself, and use my watchmaker’s lathe to turn the correct size bushing.
I start with a 3mm brass rod. I first drill a 0.30mm hole in it, and then turn the rod to the required diameter. I will adjust the exact hole diameter later with cutting and smoothing broaches, to ensure a perfect fit around the pivot hole.
I create a small chamfer to make it easy to press the bushing in the bridge hole. A recess is also required to act as an oil sink. I then start cutting the bush to the required thickness.
The bushing is made, but the surface finish is not yet good enough for the intended function.
So after deburring the hole, I polish the bushing face with very fine emery sticks, until I am happy with the finish. I then finish the hole with cutting/ smoothing broaches to get the perfect fit on the pivot. With this done, all I need to do is press the new bushing in the bridge, and adjust its height with the jewelling tool to have the correct endshake.
With all of this out of the way, I can now proceed with the more straightforward part of re-assembly. Starting with the mainspring and barrel assembly which has been cleaned and lubricated.
I then lubricate the balance end stones, and fit them to both sides of the movement.
On this movement, the keyless work fits under the barrel bridge, so I need to install this before I go any further.
I can now fit the barrel bridge and train bridge.
Ratchet and transmission wheels are installed, as well as pallet and pallet cock. Note the new bushing on the fourth wheel, it does not look much does it, considering I spent a few hours making it!
And after installing the balance wheel, I can now complete the assembly of the movement by finishing the dial side.
My last job on this watch is to replace the crystal which had a few scratches.
The watch is now a remarkable timekeeper, with excellent amplitude. I normally finish articles on my blog with a photo of the watch face, in this case I think it is appropriate to show the other side in all its beauty now that the job is done!