"Record" pocket watch case back opening

[AshF]

Hi all,

I've got this pocket watch and I can't get the back off.  From my research it's a screw back.  The front screws off nicely but the back is stuck.  I've applied quite a bit of force but any more and I'll break the stem.  I've searched the forums and seen some people use hot glue, and WD40.  I don't have got glue but will try WD40 later.  Any other tips or suggestions?  There are no grooves or hinges at any point on the case.

 

Many thanks,

Ash.

[watchweasol]

Hi  You can either use a sticky ball and try that or superglue a large nut to the back and use a spanner to turn the back off. The nut can be removed using acetone (nail polish remover).  Never had a problem with this method on stubborn back .

[Tudor]

The trick with this one is holding that case to do the "unscrewing".

Is it a silver case? If it's brass, or better plated steel, you might be able to hold the case (with aluminum shims for protection) in a lathe chuck while you get medieval on the back gluing the nut does work, although I have not ever reached that pinnacle of watch repair (yet).

Another consideration: IF the threads on the cover are female, heating the cover gently (alcohol lamp) should expand it enough to use the sticky ball. If the threads are male, you need to shrink the cover, which you can do by inverting a can of "air" used for cleaning keyboards etc. and spraying it with the freezing cold liquid.

Perhaps consider a strap wrench, since it's smooth. (just an idea)

When the cover and midcase are the same material, and especially when it's soft, the threads can gall and be nearly as strong as a weld. I did the 'freeze trick' with a Titanium back on a Titanium mid case not too long ago and it worked surprisingly well, considering the force exerted (using the correct tool) prior to freezing, which did not budge it. After freezing, the sticky ball took it right off like butter.

Then, once it's apart, you need to clean, perfect and polish the threads on both sides, and apply a few drops of your favorite grease so next century, the next guy can get it open.

Good luck.

[eezy]

Suction cup off my satnav windscreen mount works for me. Twist it gently don't snatch.

[AshF]

I never thought that superglue and a 13/16 inch spanner would be such useful watchmaking tools...

Thanks again for all your suggestions.

 

[Tudor]

Superglue fixes a great many things...