Argh. Breaking pallet pivots

[WpgRob]

Beginner here. Of about 60 watches I’ve serviced and repaired, I’ve broken a pallet pivot on three, always during disassembly, and usually when the old oil has transformed to glue. Each watch was Swiss, in case that makes a difference. Here’s what happened in each case:
- unscrewed the pallet bridge or cock

- gently inserted a screwdriver in the  slot under the pallet bridge or cock

- gently but firmly rotated the screwdriver, avoiding a forwards force on the screwdriver. If alignment pins stick, the cam action is alternated back and forth between back corners of the plate.

- heard a small but horrible click.

Is there a special tool or technique for safely lifting the pallet bridge? Should everything be soaked in naphtha before beginning disassembly if there’s any sign of old oil gluing parts together?

Thanks!

Rob

[HectorLooi]

55 minutes ago, WpgRob said:

Of about 60 watches I’ve serviced and repaired,

60! Wow, that's a lot.

Can't say I understand the problem because disassembly is usually quite uneventful, except for springs launching into space. Most people break pivots during assembly.

I use a homemade brass pry tool to loosen parts. It's just a short length of hard brass wire sharpened to a chisel point. Don't pry at just one point and crowbar it out. Pry at the notch and when a crack opens up, slip the pry tool in and loosen it at a few more points until the bridge is free.

[Nucejoe]

 If a runner, I usually let the movement run in naphta for a minute, some movements need a bit of encouragement to run in liquids, so a quick dip of the movement in naphta then remove and encourage the oscilator with puffer, repeat several soaks. 

Or if you don't want to soak or dip the movement in cleaning solution ,   keep putting naphta on jewel holes as the movement runs on bench.

A pre-clean of some sort  helps.

 Avoid lifting out the fork with tweezers or any tool.

 Try blowing fork pivot out  with strong puff of air from jewels holes back side.

Good luck .

 

 

 

Edited 13 hours ago by Nucejoe

[caseback]

Wiggle it back and forth, small steps, keeping the pallet cock as level as possible and take your time (!). You could also use an extra tool as a safeguard at the jewelled end to avoid pressure on the pallet fork.

You also mention lubrication... On the pallet fork pivots??

[JohnR725]

it would be nice to have the exact model of the watch the or a picture so we can see exactly what you're talking about. this is because the definition of Swiss watch could be a variety of things and it be helpful if we could see exactly the watch your dealing with

then in professional watch repair at least some professionals they do pre-cleaned watches. In other words the hands and dial come off and the entire movement assembled goes through a cleaning machine sometimes I think a shorter bath perhaps so everything is nice and clean for disassembly makes it easier to look for problems.

Then other professionals don't like pre-cleaning because it basically obliterates the scene of the crime. Especially when dealing with vintage watches where you're looking for metal filings and problems that may visually go away with cleaning.

Then usually super sticky lubrication isn't really a problem for disassembly and typically shouldn't be a problem on a pallet fork bridge because there shouldn't be any lubrication on the bridge at all as you typically do not oil the pallet fork pivots.