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Howdy gang,

Need help with a little problem I'm having.  Working on a 1930 Elgin 12s pocket watch that had a broken balance staff pivot.  I need to remove the cap jewel so I can test the fit of the new staff in the jewel hole.  I've removed the screws but have been unable to get the cap off.  Looks like it may have been a tight fit from the get go and someone pressed it in before inserting screws.  I included the dime in the picture to show scale of what I'm working with.  There's no gap that I can find to pry on and rodico doesn't work.  I tried some sticky tape but no luck.  Any suggestions on how I can grab it?  Not sure how much effort it's going to take to dislodge it. Don't want to damage it.

capJewel.jpg

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These are a light press fit, along with a setting below holding the hole jewel. It should be pressed out from the underside. They used to sell star shaped tools with different diameter brass pieces  that were used for pushing out these jewels. If you have a jeweling tool that's perfect.  But pegwood works fine except for very stubborn ones

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Be very careful. I've broken one before. Your staking tool must rest on the brass chaton, not on the jewel. If you have a Seitz jewelling tool, that's even better.

Over tightening of the 2 retaining screws could have deformed the chaton but I believe that the brass chaton deformed over time due to molecular creepage and became stuck. Some of these pocketwatches are over a hundred years old! 

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43 minutes ago, HectorLooi said:

It varies. Sometimes the screws are on the underside of the balance cock and you'd have to unpin the hairspring and remove the balance wheel to get to it. It's a real PITA. Never understood why they were designed that way.

Except for really cheap and/or cylinder movements you can release the stud, no need for unpinning the hairspring. Most non-shockprotected watches have the hole jewel in the cock, cap jewel set in a disc that holds the regulator, screws from underneath. Really old and pocket watches, screws from the top sometimes; American and Swiss emulators, with screwed down settings for both cap and hole.

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Just to update the group, I was able to remove the jewel set by pushing from the hole side.  Both popped out without incident.  I found an Elgin Watchmaker class PDF on line that showed how it's put together.  I want to thank nickelsilver for pointing me in the right direction.

elgin.JPG

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  • 7 months later...

I had to remove a cap jewel today and only found this thread after the fact.  In my case, the cap jewel was not so stuck, but it was stubborn.  I wondered about pushing from below as described in this thread, but ultimately was successful popping out the cap jewel.  In the future, I will put my Seitz to work and press the whole thing out.

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  • 7 months later...

I had my first of these today. I assumed I'd be able to just lift it out with Rodico and & was very disappointed to find that didn't work. I really hoped I wouldn't have to remove the balance from the balance cock, as I had already messed up another one last weekend in that operation (though the 18s Elgin hairspring stud is far bigger and easier to work with).

Anyway I couldn't get it out, found this thread and removed the balance. The jewels pushed right out with pegwood. I cleaned them, and reinserted the cap jewel upside down. This had two noticeable effects: 1) one of the screws sheared off half its head and the other wouldn't catch threads because they could not drive in flush, and 2) the balance would only run dial-down, visibly falling a solid half-mm when flipped into dial up. This would have been a 5 minute job if I had put it together right the first time. Instead it was 25min and I learned some things.

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I was just going to start a new thread to ask a similar question, but since you've already got one, I hope it's okay to piggyback.

I have an Incablock style shock setting from a Bulova movement, and the cap stone is stuck firmly to the hole jewel. It's gunky enough that it stops the balance from turning!

If I don't have anything thin enough to poke through the hole jewel, any other options for prizing them apart? I've tried soaking in solvent and a run through the ultrasonic, then Rodico, then sticky tape.

Sure looks neat, though.

eye.thumb.png.65dd94c28a36dfdd5b93b8d5b0531f6b.png

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16 minutes ago, ManSkirtBrew said:

 I don't have anything thin enough to poke through the hole jewel, any other options for prizing them apart? I've tried soaking in solvent and a run through the ultrasonic

How about the pivot of a scrap balance?    

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13 minutes ago, Nucejoe said:

How about the pivot of a scrap balance?

I just tried--turns out the only scrap balance I have lying around is from a large pocketwatch, and the pivot doesn't fit in the jewel hole 😕

Turns out the answer was "lots and lots of poking and prodding on a Rodico blob."

Looks more like shellac than oil. I did see a Youtube video the other day where someone used CA glue to hold a cap jewel in place, so very little would surprise me.

But that sure explains why the balance didn't move!

2080421275_RawPhoto.thumb.jpg.1f805a35c9c81d44156787c021f94c76.jpg

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    • Somewhere in the back of my mind i thought you had the jewelled seitz pivot gauge, i was just asking if you had this scaled pin gauge as well. I might have just made up that thought  H. 😅
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    • Yes, I understand that indeed.   Which is exactly what I am lacking, as I said. That's why the ring diameter matters to me.   That matches my anecdotal observation indeed. It could be the material or the modern backward curve that provides more power.   This is an interesting topic!  While these old oils were maybe thinner, their friction-reducing effect may still actually be lower than modern (even thicker oils), no? I man, some old, thin, organic oil may be less effective in reducing friction than a modern, thick HP1300 or so. What do you think?
    • Here are a couple of pictures of the tool that I mentioned in my first reply: Got the picture from here: https://klocksnack.se/threads/hobby-hörna-hemma-verktyg-tips-och-trix.163821/#post-4291582
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