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Old style rubbed in jewels

TimFitz

By TimFitz
in Watch Repairs Help & Advice

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TimFitz WRT Addict

TimFitz

Posted
Posted

I am ready to tackle replacing a rubbed in jewel on a Hamilton  18s #934 pocket watch movement. I have done the other kinds, but have been waiting until I have been working on watches for a few years before I try this. Many people say don't buy those old watches with rubbed in jewels, why work that hard, buy more modern ones with the screws holding them In.

Well I like a challenge,  so I have an old school set of tools to do the job. (photo attached )

Does anyone have advice on the pitfalls or tricks I need to know? Maybe a link to a video?

I would be much obliged

tool.JPG

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BUSAKAZ WRT Addict

BUSAKAZ

Posted
Posted
On 01/11/2017 at 8:13 AM, oldhippy said:

Tim, theres a thread on this forum about rubbed in jewels. If you use the search you should find it. Good for you in having a go at something different.

Mark has done a video on rubbed in jewels

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  • 3 years later...
nickelsilver Distinguished Member

nickelsilver

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The thing with rubbed in jewels is everything is wonky. The original jewels had a specific form usually quite domed with a distinct bevel on the underside. If you have a stock of antique jewels you might find one that fits your pivot _and_ fits the plate/bridge diameter. Provided you have that, often the material of the bridge/plate has become quite fragile, from time as well as being work hardened from the original burnishing. So sometimes the material that you want to reburnish crumbles apart.

 

If you don't have antique jewels, friction jewels lack the pronounced bevel that takes the burnished over material. They can be modified but it's a process with diamond paste and lathes and grinding gear. Sometimes though you get lucky and a Seitz jewel will seat and hold. You also have no adjustment for height, where the jewel seats is it.

 

On many antique pieces I will bore out the whole jewel area, including the dome often cut into the plate/bridge outside the jewel. Then make a bushing that fits well and will take a friction jewel. The bushing gets its concave dome, finished properly,  jewel gets fitted, all pressed in and you have at least a few hundredths of adjustment as well and if you use german silver on a grey bridge it's invisible (for gold plated best to plate the bushing). If it's not a Breguet or other historical piece this is often the best possible repair. For a Breguet you make the jewel, period. No boring out of that stuff.

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