Girard Perregaux Identification

[Stevelp]

Hi everyone!  So I found this guy lying in the bottom of a pile of parts watches and was wonder if someone could help me identify it?  I would like to dive in and fix it up but I have a bit of a concern when it comes to the possibility of radium dials.  I see so see what looks like luminous dots at the hour indicators but I don’t know what it is.  Any thoughts would be great!  Thanks!

[AndyHull]

Assuming you don't have a geiger counter, then the next best thing is a UV torch (the sort of thing used to check bank notes).

Shine it on the dial, while sitting in a darkened room, and if there is any phosphorescent material on the dial (zinc sulphide generally), then it will glow. This of course doesn't tell you exactly what the luminous paint is, but you can make an educated guess from the age of the watch, and the info here -> https://en.wikipedia.org/wiki/Luminous_paint#radioluminescent_paint
 

The zinc sulphide degrades over time, so even if the watch doesn't appear to have active lume, this doesn't mean it isn't mildly radioactive.

I don't think these things actually present a significant radiolgical hazard, so long as you treat them with the same caution you would if handling any other hazardous material. Wear nitryl gloves, avoid breathing in any dust from the watch, wash your hands afterwards and you should be fine. Once the case and crystal are back on, the amount of radiation they emit is so small as to be almost unmeasurable, since it is mainly alpha radiation, which would be stopped by a thin piece of paper. You probably encounter similar levels of radioactive material of one sort or another daily anyway, especially if you live in an area where there is granite in the rocks, or you have granite work surfaces.

See here->  https://www.watchrepairtalk.com/topic/10086-radon-hazards-of-luminous-timepieces/?tab=comments#comment-91769

.. for a more in depth discussion of luminous dials.

Edited January 10, 2019 by AndyHull

[oldhippy]

Don’t worry about radium dials. I used to handle them for years and I have not grown two heads. This is just one you have found. You need to remove the hands and dial and take a good clear photo of the keyless work. That is the way to I D watch movements.

[WatchMaker]

@oldhippy is of course completely correct and normally the keyless works are what is necessary to accurately identify a movement. In this case however enlarging the picture there's a '20' on the barrel bridge which puts it at this model: http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&&2uswk&Girard-Perregaux_20

You might therefore also be interested in this: https://forum.tz-uk.com/showthread.php?419737-Resurrecting-a-Girard-Perregaux

[Nucejoe]

in 1978,  I graduated collage of Nuclear power Engineering. Girard perregaux dials weren,t so scary back then, eversince though I have come to realize, I don,t know what Girard perregaux didn,t know eiher.     

 

[yankeedog]

Way back in the day , the ladies who painted radium dials had all sorts of health problems.They would sharpen the point of their brush by putting it in their mouth. As a precaution, wear gloves, wash hands and do not lick the dial.

[AndyHull]

1 hour ago, yankeedog said:

Way back in the day , the ladies who painted radium dials had all sorts of health problems.They would sharpen the point of their brush by putting it in their mouth. As a precaution, wear gloves, wash hands and do not lick the dial.

.. and even if you do decide to lick it, I think you are more likely to get Delhi belly from licking the dial than any radiation effects.... but don't... not even if you are sorely tempted to find out what it tastes of. 

You should wear gloves or finger cots anyway when removing any dial, or handling the mechanism as it stops you from putting nasty corrosive fingermarks on them. You may not notice them initially, but once they have been on there for a few weeks, those greasy sweaty paw prints can destroy the dial and set up corrosion on metal parts.
 

[Stevelp]

Sorry for the delayed response everyone!  Thanks so much for all the information!!  Haha yankeedog and andyhull, I will do my best to resist the urge to lick the dial.  I have made it habit to use finger cots at all times when taking down or assembling a watch. I will maybe add a mask when dealing with potential radium dials to be on the safe side.  So as far as cleaning the movement, is there any precautions needed there as far as pre cleaning any potential radium dust from the dial, I don’t really want anything like that in my cleaning solutions, or am I being to paranoid?