Corrosion on pocket watch case

[dwhite]

I have an Elgin pocket watch in a gold filled swing out case.  Where the gold filled is brassed through I have deep green caked on corrosion.  For wrist watch cases I just soak in hot vinegar and this does the job but I'm worried about the hinge in this case.  I would like to gold plate it.  To do this I would normally run it through an ultrasonic with Magic Green cleaner, briefly dip in a hot Sparex solution (an acid pickle) rinse in distilled water then plate.  The Sparex really preps a piece for an excellent plate but here again I'm worried about the acid action against the hinge pin and swing out ring.  I don't want to take the case apart.  Anybody know if this will damage the case or have any suggestions?

[vinn3]

Quote

 

a watch repair book might tell you the right way to polish a case.

[dwhite]

I tried another case that did not have a hinge pin in Sparex.  It was deeply corroded also and while it didn't have a hinge pin, it did have a steel stem in it.  It stripped all the corrosion off in about 2 minutes with a warm, not hot, solution.  It doesn't appear to have hurt the stem at all.  I rinsed it off and put it into a hot solution of Magic Green in an ultrasonic cleaner and the dirt and crud exploded off the case.  I'll need to hit it with a buffing compound and repeat the procedure in reverse but I think it will work fine for the hinged case.  It did separate the glass crystal from the ring which I assume I can glue back in.  Now if I can get the movement put back together with no parts left over so it doesn't join the collection of watches I've ruined I'll be good.

[Stymied]

I was going to say "just polish it" but then I started thinking about so many of my silveroid cases that have corrosion on them.

The Ultra-sound took off the dirt well enough, but the corrosion is really tough. Is "sparex" a brand name and where does someone 

usually run across it. 

Best Wishes, 

Bruce