Radium Turned White???
Like Tree2Likes
  • 2 Post By GeneJockey

Thread: Radium Turned White???

Results 1 to 10 of 10
  1. #1
    Member thoth's Avatar
    Join Date
    Aug 2009
    Location
    Wisconsin
    Posts
    5,007

    Radium Turned White???

    This watch arrived yesterday. Simple Calvert with an ETA 1080 in stainless. I was playing around with my blacklight and shined it on the dial. The hands and numbers began to glow. Not unusual. But this morning I noticed the minute hand has turned a white color and there is a fine white powder under the crystal. I would not think shining a light on old radium would activate it to do anything but cause the old material to glow. Thoughts?



    Sent from my SM-G920R4 using Tapatalk

  2. #2
    Member Dan S's Avatar
    Join Date
    Jan 2012
    Location
    Colorado
    Posts
    6,328

    Re: Radium Turned White???

    You probably know this, but it is not the radium that is luminous. The radioactive decay of the radium provides energy to excite luminescence in the phosphor layer coating. So if you saw luminescence, it was because the UV light from your source was exciting the phosphor (zinc sulfide or some such). I would not be surprised if the hands had been re-charged with a thin secondary layer of phosphor at some point, because this was sometimes done. I'm not sure why it would be have been damage by exposure to the UV light, but that is apparently what happened. Most likely the white powder is phosphor, but you can't rule out the possibility that it contains some radium.
    -- Dan (formerly known as @badbackdan)
    ------- @oldwatchdan on Instagram -------

  3. #3
    Member thoth's Avatar
    Join Date
    Aug 2009
    Location
    Wisconsin
    Posts
    5,007

    Re: Radium Turned White???

    Quote Originally Posted by badbackdan View Post
    You probably know this, but it is not the radium that is luminous. The radioactive decay of the radium provides energy to excite luminescence in the phosphor layer coating. So if you saw luminescence, it was because the UV light from your source was exciting the phosphor (zinc sulfide or some such). I would not be surprised if the hands had been re-charged with a thin secondary layer of phosphor at some point, because this was sometimes done. I'm not sure why it would be have been damage by exposure to the UV light, but that is apparently what happened. Most likely the white powder is phosphor, but you can't rule out the possibility that it contains some radium.
    So don't sniff the dial or lick the hands. Got it.

    It is interesting that the phosphor would react to the light and create, what appears to be, oxidation to the material.

    Now the question is...can I get it to go back to the dark color or can I try and get the hour hand to go white too. Got to try and get it to match lol. I paid $20 for the watch so I am not overly worried about it having some massive value I would be destroying.

    Movement for those that like movement pics.....ok..we all do but anyway...


  4. Remove Advertisements
    WatchUSeek.com
    Advertisements
     

  5. #4
    Member thoth's Avatar
    Join Date
    Aug 2009
    Location
    Wisconsin
    Posts
    5,007

    Re: Radium Turned White???

    So I read that radium is a white, salt looking, material that oxidizes to black when exposed to nitrogen. Is it possible that the reaction with the UV by the phosphor caused a reaction to the binding agent and has caused it to release the radium as the white powder?

    So even more not licking the hands or sniffing the dial?

  6. #5
    Member Dan S's Avatar
    Join Date
    Jan 2012
    Location
    Colorado
    Posts
    6,328

    Re: Radium Turned White???

    Could be. But I think that it could also be a degradation product of the phosphor, which seems more likely to me, since you obviously observed that the phosphor was excited by the UV. However, I wouldn't bet my life on it.
    -- Dan (formerly known as @badbackdan)
    ------- @oldwatchdan on Instagram -------

  7. #6
    Member thoth's Avatar
    Join Date
    Aug 2009
    Location
    Wisconsin
    Posts
    5,007

    Re: Radium Turned White???

    Any suggestions on darkening it again?

    Sent from my SM-G920R4 using Tapatalk

  8. #7
    Member Dan S's Avatar
    Join Date
    Jan 2012
    Location
    Colorado
    Posts
    6,328

    Re: Radium Turned White???

    Quote Originally Posted by thoth View Post
    Any suggestions on darkening it again?

    Sent from my SM-G920R4 using Tapatalk
    The white powder may be loosely attached, so it could possibly be brushed off or removed with something tacky. But I really urge caution.
    -- Dan (formerly known as @badbackdan)
    ------- @oldwatchdan on Instagram -------

  9. #8
    Member thoth's Avatar
    Join Date
    Aug 2009
    Location
    Wisconsin
    Posts
    5,007

    Re: Radium Turned White???

    Fixed... I do my IT work and watch work at my desk lol





    Sent from my SM-G920R4 using Tapatalk

  10. #9
    Member
    Join Date
    Oct 2010
    Location
    SF Bay Area, California
    Posts
    1,995

    Re: Radium Turned White???

    A little time spent on Google, and I learned that on milligram of radium emits about 1 millicurie of radiation. Radium dialed watches generally contain about 0.2 MICROcuries of Radium, so about 0.2 micrograms of radium.

    This pretty much means that even if you concentrated all of it into one spot, you wouldn't be able to see it. So, no, you're almost certainly not 'seeing' the actual radium.
    thoth and DragonDan like this.
    Don't take life so serious, son. It ain't nohow permanent - Pogo

    My Elgin Blog...

  11. #10
    Member thoth's Avatar
    Join Date
    Aug 2009
    Location
    Wisconsin
    Posts
    5,007

    Re: Radium Turned White???

    Good to know. I was wondering about the amount used. I was reading a old old old article about radium that suggested that all of the radium ever made up to that point could fit in a single teapot.

    1917 St. Nicholas Vol 44 Part 1 Page 376.

    "For the latest market quotations on radium call for a price of about $15,000,000 per pound! Perhaps all of the radium ever isolated since its discovery would hardly fill a good-sized tea-pot!"

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

    Similar Threads

    1. What's happening to my rubber watch strap? Turning white!
      By anonymousmoose in forum Straps & Bracelets
      Replies: 12
      Last Post: December 11th, 2016, 02:25
    2. Advise needed: turning white back to white
      By PaulGeo in forum Casio G-Shock
      Replies: 4
      Last Post: January 11th, 2008, 05:30
    3. Rolex Thunderbird 18k White Gold Turn-O-Graph Bezel!
      By eWristwatch.net - Don Bre in forum Watches - Dealers and Manufacturers
      Replies: 0
      Last Post: June 28th, 2007, 17:59
    4. Will White Dial turn yellowish over time?
      By plinius in forum Public Forum
      Replies: 2
      Last Post: July 30th, 2006, 16:48
    5. Replies: 13
      Last Post: July 29th, 2006, 17:53

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •