Repair Rub In Jewel Setting

[margolisd]

So, I was somewhat cavalier trying to replace a rub in jewel. I don’t have the correct tools but thought I could expand and close the hole with nothing but my jeweling tool, some peg wood and my wits. It didn’t go well. I’ve taken a big. chunk out of the thin metal that wraps around the jewel. To be fair, the jewel still sits in the hole and feels relatively secure with only 200 degrees of metal holding it in place. But I just can’t close the watch knowing it’s been bodged. So is there a technique for replacing a rub in jewel setting if it’s damaged? I’m guessing it needs drilling out and soldering in a new setting. Which would be beyond me for now. Is there another way?

[rduckwor]

Possibly sending it off for laser welding?  Seem extreme, but that may well be one answer.

Good Luck,

 

RMD

[oldhippy]

Watchmakers shellac is the only way I know of that would prevent the stone from moving. I don't like using modern glues, as you never know what reaction to watch parts it might have. 

[margolisd]

Thanks both. Could this help me create a new larger hole? And I'll just find a suitable jewel to fit? I've never seen one of these before and I have no idea how they work.

https://www.ebay.co.uk/itm/Vintage-Watchmakers-Jewellers-Brass-Jewel-Hole-Cutting-Tool-Set-Boxed/383062301696?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

[vinn3]

glue (shelac) is only going to work if there is a "minium" space between the hole and the stone.   send it out.  i tryed epoxy one time,  it dint work good.     vin

[nickelsilver]

8 minutes ago, margolisd said:

Thanks both. Could this help me create a new larger hole? And I'll just find a suitable jewel to fit? I've never seen one of these before and I have no idea how they work.

https://www.ebay.co.uk/itm/Vintage-Watchmakers-Jewellers-Brass-Jewel-Hole-Cutting-Tool-Set-Boxed/383062301696?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

That's for making a new setting. I haven't used one either but it's a neat looking tool.

A big problem when replacing bezel set (rubbed in) jewels is that the brass or german silver is often quite brittle. If it's a regular commercial grade watch and you don't mind altering it, the easy route is to ream the setting to the closest friction fit jewel that will go. In some cases you can use the "walls"of the old bezel set jewel. If it's a nice piece, like an old LeCoultre or something, I will open up the bridge or plate in a faceplate. There is almost always a polished sink around the setting; I'll open up till that is gone. Then make a new setting that frictions in, which gets the polished sink on the visible side, and the repair is effectively invisible.

[oldhippy]

I did see that tool on ebay the other day. I have never seen it before, so I don't know how to use the thing. 

[margolisd]

Well I purchased that tool. Just because it looks really interesting. I'm not sure how it works but I have plenty of scrap movements to practice with.

I might see if it helps me make a new setting. But more likely I'm going to ream out a friction fit hole as suggested by Nickelsilver above.

The question is, what stone should I buy?

The jewel is for a pallet fork (lower). The fork pivot is 0.141 according to my super accurate micrometer. If it's anything to go by the upper jewel hole looks to be around 0.2mm. But it's tricky to measure. Would a 0.2mm hole be correct for a pivot of this size? I'm not sure what the ratio of pivot diameter to hole diameter should be for a pallet fork.

I measure the jewel setting diameter 1.51mm. But it's also difficult to measure.

I was thinking of going for a Seitz flat jewel 1.6mm with a 0.2mm hole. (Seitz don't make an olive jewel in this size.) Does this sound sensible?

[nickelsilver]

You want about 0.01mm of freedom in the jewel, so a 0.15 would be great, 0.16 probably still fine, 0.20 would be way too big.

[margolisd]

I went for 0.15. It worked great

[margolisd]

So, here is the interesting jewel cutting tool from eBay. Just arrived today. It's really nifty. I can't find anything about how to use it so I'm making this up as I go along.

Let's define some technical terms.

1) Turny bit

2) Spiky thing

3) Edge gougers

4) Locking screw

5) Size guide

6) Maybe thing for a bow

It appears that you place the spiky thing into your desired jewel hole on the size guide. You turn the turny thing until the edge gougers fit into the guide edge of the hole. Then you lock the spike with the locking screw.

The edge gougers are clever. Each one is split. So I think the inner gouger carves out the floor of the setting for the jewel to sit on. And the outer one creates a wall that you can later use to bend over the jewel and secure it. Because am I right in thinking this is producing a rub in setting?

I had a couple of gentle attempts on a thin scrap piece. I used it to ream an existing hole. I would presume you need a pilot hole to start with close to the correct size. I wouldn't like to use this to make a hole from scratch.

I am using this freehand. But would you agree that 6 could be a thing to use a bow? Like you would with a jacot tool? But then the tool needs to be held on some kind of stand or device to keep it vertical and steady. So I'm not sure. It certainly doesn't feel very ergonomic using it freehand.

And why are both ends spiked?

 

[nickelsilver]

The rear point would have fit in a divot in a vice to support it while it was worked with a bow. The plate would be handheld. Yes you need a premade hole to begin with.

Watchmaker's vices used to come with the little divots in the jaws for the many bow powered special tools.