Doxa women's watch (radioactive)

[stm]

Hi,

I bought this Doxa ladies watch on Ebay. My Geiger counter clearly shows that it has radioactive lume.

Is it possible to identify the year of production and whether the lume is Radium or Tritium?

I read about the 7-digit Doxa serial numbers where the first two digits indicate the year of manufacturing. That would mean that the watch is from 1953. For that it is in very good condition, but is the design consistent with  the 1950s?

[AndyGSi]

Yes from the Serial No it's 1953 and from that I expect it's radium so be careful.

[stm]

3 hours ago, AndyGSi said:

Yes from the Serial No it's 1953 and from that I expect it's radium so be careful.

Ok, that's good to know, thank you.

[ColinC]

Radium and the horrible story of the Radium Girls scares everyone - But there is also a lot of paranoia here.  I did a whole bunch of readings on a watch with Radium lume recently.

My Geiger counter read 2µsv/h through the crystal with the sensor part of the Geiger counter right on top of the watch.  This measurement dropped off to the normal background rate of 0.18µsv/h as soon at the Geiger counter is just a few cms away. Measuring from the back of the watch and there is virtually no increase.  The rate went up to 5µsv/h from the dial and hands when the movement was removed from the case.

To put this in perspective a Frankfurt to New York flight would give you about 50µsv of exposure and a chest x-ray about 100µsv.  Norwegian labour law states “The limit value for workers over the age of 18 years is set to 20 mSv per calendar year.” - that is the equivalent of 400 flights across the Atlantic!

I will however point out at this point it is important that you don’t ingest the radium from the watch! One of the worst things you can do is scrape the radium off the dials and create radioactive dust that you could breath in!

That being said… If for each radium lumed watch you work on you spend 15 minutes getting the movement out of the case and the dial and hands off and then another 15 minutes at the end putting the dial and hands back on your exposure would be less than 2.5µsv 

Once you have the hands and dial off they can go in a box and put safely out of the way (probably good practice for any watch!).

I believe the risks are negligible If you take precautions such as wearing a mask and gloves and wiping your work surfaces down with a damp paper towel and disposing of the towel, gloves and mask once you are finished

 

Edited 11 hours ago by ColinC

[AndyGSi]

7 minutes ago, ColinC said:

Radium and the horrible story of the Radium Girls scares everyone - But there is also a lot of paranoia here.  I did a whole bunch of readings on a watch with Radium lume recently.

My Geiger counter read 2µsv/h through the crystal with the sensor part of the Geiger counter right on top of the watch.  This measurement dropped off to the normal background rate of 0.18µsv/h as soon at the Geiger counter is just a few cms away. Measuring from the back of the watch and there is virtually no increase.  The rate went up to 5µsv/h from the dial and hands when the movement was removed from the case.

To put this in perspective a Frankfurt to New York flight would give you about 50µsv of exposure and a chest x-ray about 100µsv.  Norwegian labour law states “The limit value for workers over the age of 18 years is set to 20 mSv per calendar year.” - that is the equivalent of 400 flights across the Atlantic!

I will however point out at this point it is important that you don’t ingest the radium from the watch! One of the worst things you can do is scrape the radium off the dials and create radioactive dust that you could breath in!

That being said… If for each radium lumed watch you work on you spend 15 minutes getting the movement out of the case and the dial and hands off and then another 15 minutes at the end putting the dial and hands back on your exposure would be less than 2.5µsv 

Once you have the hands and dial off they can go in a box and put safely out of the way (probably good practice for any watch!).

I believe the risks are negligible If you take precautions such as wearing a mask and gloves and wiping your work surfaces down with a damp paper towel and disposing of the towel, gloves and mask once you are finished

 

Yes, the problem isn't so much with the 'background' radiation but inhaling or digesting loose flakes and dust that can become airborne.

[mikepilk]

10 hours ago, ColinC said:

I believe the risks are negligible If you take precautions such as wearing a mask and gloves and wiping your work surfaces down with a damp paper towel and disposing of the towel, gloves and mask once you are finished

I agree. I do the same, gloves + mask and cover the work surface with cling film. I have replaced the radium on a few dials and hands. 

You may want to keep the dial original, but If you want to remove the radium it easily dissolves in water. For the hour dots, using a cotton bud or pegwood, put a drop of water (just on the radium) and let it soak for a minute. Then with some pegwood sharpened to a chisel point, the dot should just slide off.

For hands, soak in water for a minute or two, and push the radium out with pegwood.

I replace with modern green lume. Original radium was similar in colour to modern green lume. I sometimes put a touch of orange in to make it look aged on older watches.

When finished, I wipe all surfaces and tools. Gloves, cling film, wipes, cleaning fluids, pegwood, buds etc get sealed in a ziploc back and put in the household waste.

Edited 1 hour ago by mikepilk