This is a Mickey Mouse watch made by Bradley from the 1970’s. Like most of the watches I’ve worked on it is a manual wind movement (quartz movements still being a bit pricey at the time of manufacture). The movement is a Baumgartner 134 which is Swiss made, but instead of using a Swiss Lever escapement, this movement utilizes the cheaper Pin-pallet escapement.
I picked this piece up from eBay in non-working condition and when it arrived in the post it was clear why. The crown wouldn’t budge even a bit and the telltale sign of liquid ingress was visible on the dial.
Eager to discern the extent of the damage, I went to work straight away. The case was a beast to get open but it finally gave in and released the movement following a bit of coaxing from my Swiss army knife.
The dial was secured with two screws which pass through the face and thread into the bottom plate. Most watches aren’t assembled this way, but the screws are hidden beneath the bezel.
I knew I was in trouble as the dial lifted away from the movement- the bottom plate was clearly stained with rust.
It really doesn’t take much rust to ruin a mechanical watch. The pivots for the gear train and balance wheel are quite small and will oxidize in a heartbeat. Even if the pivots are salvageable with burnishing, the pivot holes will need to be re-bushed to accept narrower pivots without excess play; in most cases that just isn’t a economically feasible solution.
The top plate looked a bit better. Perhaps when the water entered this watch it was left sitting face down?
Despite being a children’s watch, the movement is quite robust and well engineered. There is not a single wire spring inside and I was particularly impressed with the design of the keyless works. All the parts are large and easy to work with when compared to a typical service piece.
I began my disassembly by removing the ratchet and crown wheel from the top plate.
Next off was the balance cock then the top plate. Beneath I found more rust.
Removal of the barrel uncovered the worst of the damage.
This was not pleasing, but the pivots on gear train seemed to be okay and the escape wheel was unaffected so the parts didn’t go into the rubbish bin just yet.
Other gremlins hid inside the mainspring barrel. I’m not sure how the tail of the spring became so damaged.
Before sending the parts off for cleaning I snapped a picture of the pallet and escape wheel for this piece next to the same parts from a Swiss Lever escapement. The simplicity of the Pin-pallet design is apparent.
The bits and pieces cleaned up nicely so I began assembly.
The mainspring in this movement is particularly long, a replacement was readily available from Cousins.
With the new mainspring installed and the gear train in place it was time for the top plate.
It was now time to deal with the cap jewel. This movement is a single jewel movement; the pivots for the balance wheels rest on brass bearings and the lower pivot is capped with a disk of polished steel. The top pivot is capped with a standard ruby cap jewel, but the shock spring is a pain to replace. Fortunately harsh language seemed to do the trick.
It was time to fire up the engine. The results on the timegrapher were not spectacular but there really isn’t a compelling reason to revisit the work; I can live with the watch gaining or losing a minute or two a day. Hopefully as the lubricants are distributed the amplitude will rise a bit. I’m not sure I can fix the jittery beat.
A replacement dial and case were sourced from a donor which was internally in worse shape. The dial is much prettier and the plating on the case is free of wear. I like the silver color as well.