Replace base plate balance jewel (or not?)

[bsoderling]

Hello friends,

 

I’m (again) working on an old no-name movement, probably from the 30’s as it’s got a tank case with an art-deco style dial.

 

Looking closer, I realize that the balance jewel is slightly flaked off on the outside but the hole seems fairly ok, possibly a bit enlarged.

 

Checking the pivot, I see that it tapers off, I guess due to wear, towards the end which in combination with the possibly enlarged jewel hole ends with significant side shake.

 

I found a replacement jewel in my small stash of jewels that seems to fit nicely on the pivot (as can be seen in the photo).

 

I can’t make up my mind if the best approach is to leave things as they are or fit the replacement jewel and hope that works...

 

Any thoughts or experiences from wear and tear like this is appreciated.

 

 

 

 

 

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[clockboy]

If the jewel hole is damaged I would change it. 

[nickelsilver]

You should definitely replace the jewel, preferably with a convex jewel with olive holes. But anything is better than a chipped jewel. The pivot really needs refinishing too but the jewel is critical.

[bsoderling]

I’m beginning to see where this is leaning... :-)

The jewel I have is indeed of the convex type and hole diameter just 9/100 mm so I think the pivot diameter has gone down quite a bit due to wear.

You mention refinishing of the pivot. Is work on the existing staff/pivot really possible or did you mean swapping out the staff?





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[nickelsilver]

The pivot could be refinished somewhat but would be pretty loose in the jewel, possibly leading to clearance problems with the escapement. Either a smaller jewel could be fitted or the staff replaced. The latter being best.

[yankeedog]

clean the pivot, replace the jewel.see how it works.

[bsoderling]

An update...

Decided to follow advice and swap out the bad jewel.

The replacement jewel fitted nicely and for the 2nd time I made use of the old Seitz set I bought a while ago.

After a clean and lubrication the movement started up nicely with an amplitude at 270 with the old main spring, which must be a good thing on an oldie like this.

Re-lumed the hands and may try to color the lume a bit as the new stuff stands out a bit too much.

Dial and casing is not on the fancy side but I like the art-deco number style.

Photos attached.

Thanks for good advice and support!




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