Adding jewels where there are not

[aac58]

Hi guys:

I know there are people that add jewels on vintage watches in areas where there are some wear, one example can be the holes were the barrel arbor sits, or other holes for wheel pivots with no original jewels. I work with Seikos and the 6309 doesn't have jewels in the train bridge for the 2nd and 3rd wheels, it would be nice to add jewels there.

I know it's far from my habilities, so I'm not planning to do it in the near future, but just out of curiosity, how is it done? What tools are needed to add a new jewel? Anyone here have done it?

[Tmuir]

You need a jeweling tool, the name really says it all.

A complete tool has reamers to ream the hole out to 0.01mm smaller than the jewel you want to fit and then has pushers you use in the jeweling tool to fit them. How to correctly use a jeweling tool is a whole other topic though.

Main brands are Seitz, Favorite or Bergeon but there are other brands.

This is a pretty typical example.

https://www.ebay.co.uk/itm/FAVORITE-Delux-Jeweling-Tool-Watchmakers-bench-Tool/223723978922?hash=item3416fd00aa:g:r0gAAOSw50VdqTT9

 

I have done it before, but on valuable watches its considered bad practice to change the watch, the correct thing would be to bush back with brass is it didn't have a jewel before

[vinn3]

Quote

 

  ALSO in the case of exsesive wear,   the brass hole may be elongated.  that may require advanced math. to find the original hole location.   best to close up the hole as mentioned above.    vin

[nickelsilver]

In my experience opening a hole much more than one or two jewel sizes (0.10- 0.20mm) runs a real risk of losing the original hole location. It may drift just a hundredth of a millimeter or two, which for a barrel or center wheel might not matter too much, but for smaller wheels with finer teeth and closer pitching it can cause issues. As vinn3 mentions the hole can be elongated too, which requires at the least "drift broaching" back to approximate true center before continuing. I personally wouldn't try to open a hole that was unjeweled up to a size suitable for a jewel with reamers, I would do it in a faceplate. There are numerous techniques for centering, the classical being a long piece of pegwood and more modern using optics. I won't get into the entire process as it's covered in numerous books but the pegwood technique is fairly simple but hard to explain clearly without getting long winded.

[aac58]

Thank you for your answers, as I thought this is a task for very experienced watchmakers, but it is interesting to know.

[jdm]

4 hours ago, nickelsilver said:

I won't get into the entire process as it's covered in numerous books but the pegwood technique is fairly simple but hard to explain clearly without getting long winded.

Any book recommendation is welcome. My library is so scarce. 

[nickelsilver]

2 hours ago, jdm said:

Any book recommendation is welcome. My library is so scarce. 

Henry Fried's Bench Practices for Watch Repairers and Daniels' Watchmaking are two off the top of my head.