Accumulation of rust-like crud on balance after cleaning.

[MrRoundel]

Well, this is interesting. I used my Watchmaster/Bulova ultrasonic to clean a GP movement this morning. After pulling the jewels, I cleaned the pillar-plate with the balance in place. When I pulled it out, it had rust-like stuff on the balance rim. The cleaner wasn't old, but there may have been something at the bottom of the container before I started. I had no idea it would leap up and stick to the balance rim, but it seems like it may have. It's like it was debris that was super attracted to the gold balance. I just wiped out the cleaning jar with denatured alcohol to remove the varnish buildup and ran the plate/balance through another cycle. While I wait for it, does anyone have any idea what it may have been, and why it happened, and perhaps how to make it "unhappen" if it's not gone after the second cleaning? Any help is appreciated. I'll take a picture if it's still hanging on after the second run. Thanks ahead of time.

 

Edited December 20, 2017 by MrRoundel
spelling correction in title

[MrRoundel]

I ended up removing the balance, which I was loathe to do, as the watch is an 8 3/4 ligne AS 1240. Not that I have anything against A.S., it's just that we're getting into rather uncharted, size-wise, territories for me. This is getting on the small size for what I like to mess with. I'm now using pegwood and scraping off the accumulation of crud from the balance. It was even caked on the regulator pins. WTH? Oh well, live and learn. I hope I get through this watch without too many more issues. It's a rather nice ladies version of the GP Seahawk, that may be called a Mermaid. Nothing on it is marked so, but it has the same case as the vintage Seahawks in which the movement presses out of the bezel through the back, etc.

There was rust on this movement in the winding arbor and setting areas, so maybe it was on the balance already, but that seems odd that rust would accumulate with some sort of man-made help, i.e. ultrasonic energy. And I believe I would have seen it before. I, and the solution, seem to be to blame. Cheers.

Edited December 20, 2017 by MrRoundel

[Ishima]

I wonder if the balance hasn't become magnetised and attracted the corroded metal particles. 

[rodabod]

I’ve had that happen with magnetised parts in the cleaner. But it’s obvious when that happens as it’s only loosely attached due to magnetism. 

[MrRoundel]

Thanks for your responses. If it was a magnetism issue, it would seem that the crud would be on the hairspring, not the, what looks like gold, balance wheel and brass regulator pins. (I thought I had mentioned the balance LOOKING LIKE it's gold, but apparently did not. Sorry.) There was none on the hairspring. That said, I will demagnetize and re-clean to see if the particles will drop off once the parts are free of that attractiveness. Thanks again. Cheers.

 

[canthus]

I thought it was inadvisable to ultrasonically clean plated items as the plating can lift, especially if old and the u/s intensity is high/long.  Doubt if balance wheel would be plated but others may know.  I am also wary of putting fitted balance (in plate/cock with jewels) into u/s as I think the rapid impacting of the pivots with the jewel cannot be a good thing and may damage the jewels.

[MrRoundel]

I'll keep that in mind about the old plating vs. ultrasonic cleaners. Thanks.

I get what you're saying about the possibility pivot pounding against the balance jewels. While I didn't think of that, I had removed them prior to cleaning. Of course, that may be a worse idea because now the pivots can bang against the large hole in the balance cock, but it doesn't appear to have done any damage to the pivots. I guess there are varying schools of thought on cleaning with the balance in place on the pillar-plate.