Re: Radium on watch dials

[Wayne Schlitt <wayne@midwestcs.com>]

Hmmm...

I just read my last reply, and it appears that my message was
truncated.  Maybe the line beinging "From " confused some mail
server.  If the copy you received was not truncated, I apologize for
the duplicate message.


Here is the rest:


>From the sounds of it, people who have a few watches with radium dials 
probably don't have much to worry about as long as they don't take
them apart and stir up the paint dust.  People with large collections, 
or watch repair people (watchmakers), on the other hand, probably need 
to take additional precautions.


One thing that isn't clear in many of the reports of radiation
levels is whether people are measuring wrist watches or pocket
watches.  I suspect that this could make a very large difference, not
just because of the size, but because of the way pocket watches are
worn.  Traditionally, pocket watches are kept with the dial toward you 
to protect it and pointing toward your innards.  (It's really cool
that Levi jeans still have a place for pocket watches after all these
years.)

The clock collectors who have alarm clocks and such with radium dials
should consider the larger amount of radio active material, although
the 1/r^2 nature of radiation help a lot.


Of more concern to me is watchmakers who repair these watches.

The good news is that most of them will not scrape off the old paint,
but rather replace the hands with new ones *if* they are asked to do
so.  The bad news is that they are still likely to stir up most of the
dust that is in the watch.

The mechanical watches generally should be cleaned every 3-5 years if
worn regularly.  The traditional (and best) way of doing this cleaning
is to completely disassemble the watch, throw most of the parts, other
than the hands and the dial, into a little basket.  The basket gets run
through a container of cleaning solution, and then two containers of a
rinse solution.  These solutions are not changed between watches and
only get replaced when they are too dirty.  Watch cases are often
thrown into an ultrasonic tank for cleaning.

Radium decays into radon, which I would suspect would float through
the watch.  If the daughters then stick to the watch movement and
case, you could easily have cross contamination between different
customer's watches.

One person has suggested that watch repair people wear those
disposable gloves, but I know that they will never do it.  Watch parts
are so small and need such accurate adjustments that you need all the
finger-feel that you can get.  Many watchmakers use microscopes to
work on watches.


I guess another danger of radium watches that I really hadn't fully
considered was that of government bureaucrats and their ideas of what
is considered a "perfectly safe level of radiation."  Oh boy!



Thanks again for all your help.


Oh, I'm not going to be on this list for long, but I have to say that
it will be a great loss if this list gets shutdown and the archives
lost.  I found this list via a google search that turned up some very
interested posts from the archives.  There is a lot of good
information there that I hope is not lost.



-wayne

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