Elgin 16S Grade 312 Pocket Watch – Service

My good friend David gave me this Elgin 16S Grade 312 Pocket Watch for a service and a bit of TLC. It was manufactured by Elgin which was an American company based in Illinois. I was able to date the production to 1921 from the serial number. This would have been a very good quality watch (and expensive at the time). The case is 9 carat solid gold.




What I love about old watches is that they always come with a story, although sometimes untold.



In this case, Dave had a paper written by his mother documenting the whereabouts of the watch in the family, what a lovely touch.

The story so far…


I open the watch which uncovers a stunning movement, with beautiful decoration.


I need to remove the bezel to take the movement out, and encounter the first minor issue. The bezel crystal was the wrong size, and came out of the bezel with the slightest of touch.



You can see there is also evidence of adhesive having been used to fix it in the past to compensate for the poor fit. Adhesive is not required, provided the crystal has the correct fit. The crystal was also a bit cloudy and scratched, so I will be replacing it as part of the service.

The beautifully preserved enamel dial is now off, exposing the dial side of the movement. Everything looks in order.


This is a view of the upper side of the movementELGIN-16S-Grade-312


I soon have the movement fully stripped down. Note the old mainspring which is carbon steel, possibly original to the watch, so being more than 100 years old I will be replacing it as part of the service.



During disassembly I noticed a cracked jewel, which will need replacement.







Note the beautiful blue hairspring, with a breguet overcoil. The breguet overcoil allows a more concentric development of the hairspring as it “breathes” compared to flat hairsprings. You would only find them in higher end watches nowadays.




Unfortunately, when looking a little bit closer I find another issue: one of the balance staff pivots is bent, the watch must have been dropped at some point in its life. The balance will need to be re-staffed, otherwise the watch will not perform correctly.



I start re-assembly by replacing the mainspring with a new one, made of a modern alloy.




I now need to address the main issue, the damaged balance staff. I managed to source a replacement. Before I do anything else, I check that the staff I procured has the correct dimensions as there would be little point in doing any more work if it was not.


All ok, so I can carry on, first I remove the hairspring from the balance.


I then remove the roller on the other side.


Here is the new balance staff next to the old one, believe it or not this is actually quite big as balance staffs go… they are much smaller in wristwatches.




The new staff is riveted in place.






I then check the poise of the balance after fitting the roller back on the staff. I use a balance tool with ruby jaws, and gently let the balance roll along the edges to identify any heavy spots. All is good here so I can carry on, I will do a final dynamic check of the poise on the timegrapher. 



With all the movement issues resolved, I now turn my attention to the cosmetic side of the restoration. The dust cover in the case is heavily scratched.








Now much improved!





The case was cleaned and very lightly polished by hand, just enough to remove the tarnishing you get on gold over the years.


The movement is now back in the case.


This is a close up photo of the regulator. A very ingenious design where the regulator arm is held by a screw travelling on a curved threaded rod, allowing great precision during adjustment. It also looks rather nice I think.



And finally I replace the badly fitting crystal with a brand new replacement.




The work is done, the watch is performing great again, and it does look fantastic.  It is ready for the continuation of its story in David’s family.ELGIN-Pocket-Watch-Service

3 Replies to “Elgin 16S Grade 312 Pocket Watch – Service”

  1. Olivier I love what you did with my watch and the care you gave to a treasured family hierloom

    David ( the custodian for now ) of that lovely watch

  2. I love the story.. I think Grandpa would be proud that someone is taking care of his watch!

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