Author Options:

How can I tell if my watch parts are radioactive? (for cheap... can I use unexposed film?)? Answered

I heard that sometimes you can't tell if the antique watch parts you are decorating Steampunk items with have been in contact with radium paint.



Best Answer 10 years ago

If you have really unexposed film, you could use it to check for radium. With a half-life of 1600 years, the radioactivity now is going to be pretty close to what it was originally. (~(1600-80)/1600 = 95%).

On the upside, you don't really have to worry about it from a safety standpoint, as long as you don't do "stupid" things. The amount of radium used in a single watch was fairly negligible, and the material is fully encapsulated in the paint.
Don't take the watch apart, and certainly don't start scraping off the paint. Radium is chemically similar to calcium, so if you inhale or ingest it (inadvertently, obviously) it will tend to migrate to your bones, where it can, over sufficient time, induce leukemia or related diseases.

The health problems you may have read about involved workers who painted hundreds or thousands of such watches, and were not only exposed to large quantities of material, but also probably ingested it (tipping their brushes by mouth, for example).


8 years ago

hi, its late and i wish to make a request: can you post a pic? i have trained my eye to spot radium. i can do it within 5 seconds.


10 years ago

Radium paint used to glow through it's natural radioactivity. It probably won't anymore because the activity has dropped-off. The first thing to do is look for white-ish paint on the watch face and hands, where you'd want to see it in the dark. Do you have anything like this? L


Answer 10 years ago

Just to clarify, the paint breaks down but the radium itself would still be there.

Radioluminescent paint contained radium-226 to provide the energy and zinc sulfide to convert the gamma rays into visible light. The zinc sulfide, however, degrades under the radiation exposure and eventually no longer fluoresces.

You may be able to use glow-in-the-dark paint as a radiation detector. But film would detect and record at the same time.