[clockworks]

I'm cleaning my first 7S36B in my ultrasonic tank, using L&R Ultrasonic cleaning fluid. The first part I cleaned was the main plate. After 5 minutes in the tank, I pulled out the plate, and noticed that it was covered in a sticky substance. While leaving it to drain before it rinsed it, I had a look at the fluid in the jar. At the bottom of the jar were small globules of brown sticky stuff, which looks very similar to the dissolved lacquer than I've seen after cleaning lacquered brass clock plates.


Has anyone else come across this, and is it really lacquer from the plate? I've never seen anything like this with older Seiko movements.

 

[rileynp]

When was the last time you changed your solutions? How many and how dirty have the watches been that you've cleaned since? Both (time and filthiness of movements) can contaminate the solution, causing this type of brown gunk. Watch movements in the 20th and 21st century are not lacquered as a general rule, so this is my suspicion.

 

[clockworks]

I did wonder about this, Noah, so I used brand new fluid when I cleaned the movement for the second time - still loads of this browny/gold gunk. I had to clean it 4 times, with fresh fluid each time, before the gunk stopped appearing.
On closer inspection of the gunk, it was soft, like grease, but separated out from the fluid as if it was water-based.



I've been cleaning very small clocks and a few watches this way for several years (sometimes starting with much dirtier fluid), and never seen anything like this.
I wonder if a previous "repairer" had used some unusual fluids or oils? The watch was secondhand, and had been worked on by a rather careless person. The dial was badly scratched, and one of the applied indices was missing. Even after cleaning, the watch was running very fast - about 4%. The problem was the with the balance spring, which was binding on the outer coils. I guess the previous "repairer" had messed this up as well. I straightened the terminal curve of the spring slightly to centre the spring, and all now seems well.