Should I be worried about radium?

[mikepilk]

While we are on the subject - It reminded of the my one radium watch, my Universal Geneve cal 267.  I've always wondered about how (and where) to store it. I had it sealed in plastic bag to contain the radon. But then I read about how that leads to contamination of all the contents by daughter decay elements. 

This morning I decided to remove the radium to make the watch more safely storable and wearable.  As usual, it came off easily with a wet bud.

I happen to have an old scrap spare dial from a cal 267, and found (under  microscope using a fine oiler) I could easily apply luminova to the numbers to look at least as good as the original. 

So my question is - What colour should I use. What was the original colour of radium paint? 

Edited June 5, 2024 by mikepilk

[RichardHarris123]

Baby pink.  Hehe.  Good question, I have no idea.  

[Jon]

25 minutes ago, mikepilk said:

So my question is - What colour should I use. What was the original colour of radium paint? 

I've got a bit of a collection of NOS vintage radium hands in pristine condition and they have a very mat dull lime green/yellow colour to them. I've tried taking photos of them, but the colour doesn't really show properly in them! They look more white in the photos, which they're not.

I tinted the second photo to get the colour of the lume right, although it all depends on your screen. The hand in the middle and at the top is the most like the colour

[mikepilk]

Thanks, that's really useful @Jon.

The green lume I have looks pretty close to that. I have ordered some vintage tinting paste. I'll try the basic green with just a hint of the tinting paste to tone it down a touch. 

BTW  I like the burn marks left on the card by the hands 

[Jon]

My student brought in his Geiger counter the other day and I put the tray of radium hands under it and the clicking got to a continuous crackle and some pretty high readings. That level of radiation is only problematic at close proximity. It's more the radon and breathing in dust when working with them that is the problem.

Radium exposure.pdf

8 minutes ago, mikepilk said:

BTW  I like the burn marks left on the card by the hands 

Yeah, interesting effect of the radiation on the card. You get it on vintage watches that haven't been used in many years with a faint mark where the hand was

12 minutes ago, mikepilk said:

I have ordered some vintage tinting paste

Where do you get that from?

[mikepilk]

I'm probably over cautious when removing radium. I cover the work area with cling film and wear latex gloves and an N95 mask. All the disposables I use (cling film, gloves, buds, tissue, water, which I soak up with kitchen roll) get bagged in ziplock bag and binned.

I bought a "Pocket Geiger" a few years ago (they were developed for Fukushima) which plugs in to mobile and has an app. It only detects gamma, but It seems quite sensitive. 

1 hour ago, Jon said:

Where do you get that from?

ebay

[Neverenoughwatches]

2 hours ago, Jon said:

3 hours ago, mikepilk said:

have ordered some vintage tinting paste

Where do you get that from?

Have you tried this trick with adding tea or coffee to colour lume Jon ?

[Jon]

2 hours ago, mikepilk said:

I'm probably over cautious when removing radium. I cover the work area with cling film and wear latex gloves and an N95 mask. All the disposables I use (cling film, gloves, buds, tissue, water, which I soak up with kitchen roll) get bagged in ziplock bag and binned

I do the same. There is no being too careful!

 

6 minutes ago, Neverenoughwatches said:

Have you tried this trick with adding tea or coffee to colour lume Jon ?

Yes, the results were not good. Using a water based organic material such as coffee with a solvent based lume is a recipe that ain't gonna work in my book. It is counterintuitive. I use various powder pigments to dull down the colour with the lume. Thanks for the link to the pigment you use @mikepilk

[Neverenoughwatches]

21 minutes ago, Jon said:

I do the same. There is no being too careful!

 

Yes, the results were not good. Using a water based organic material such as coffee with a solvent based lume is a recipe that ain't gonna work in my book. It is counterintuitive. I use various powder pigments to dull down the colour with the lume. Thanks for the link to the pigment you use @mikepilk

Thats another strike for the youtubers then, thats where i had heard about it.

[JohnR725]

4 hours ago, Jon said:

NOS vintage radium hands

One of the things that I find interesting with a vintage new old stock hands still mounted in the paper is the effect of the radium on the paper. In the image I snipped out you urge you can see it but maybe it's the lighting because usually the paper looks much more brown if it's been under radium hand it has a nice light burnt look.

 

[Geotex]

NOS radium lume that has been protected from moisture/humidity is much greener than I would have expected, based on some well-wrapped example hand cards I’ve come across. Very similar to 1st generation “cold” lume and other glow-in-the-dark items from the 70’s and 80’s.

[Neverenoughwatches]

11 hours ago, JohnR725 said:

One of the things that I find interesting with a vintage new old stock hands still mounted in the paper is the effect of the radium on the paper. In the image I snipped out you urge you can see it but maybe it's the lighting because usually the paper looks much more brown if it's been under radium hand it has a nice light burnt look.

 

I wonder did anyone noticed you chose a luminous green color to highlight the burn. 

[LittleWatchShop]

I have said it before, my anecdotal evidence dispels any fear of radium in the quantities we deal with in the watch world.

[AndyHull]

On 6/5/2024 at 8:08 PM, Jon said:

Using a water based organic material such as coffee with a solvent based lume is a recipe that ain't gonna work in my book.

My worry is that coffee or other "edible" pigments will be hydroscopic, and encourage mould and rust to form. This happens to some degree with older lume anyway, but I think small amounts of acrylic paint or pigment powders might be a safer option.

[oldhippy]

I don’t want to frighten you but, here is a bunch of watchmakers going to work.

 

Edited June 7, 2024 by oldhippy

[AndyHull]

You might find this interesting. It seems it might not be cockroaches that will be wearing your radioactive pocket watch in a post apocalyptic world.

[RichardHarris123]

Very interesting. 

[LittleWatchShop]

Cool.

[mbwatch]

I was googling to find out when Timex stopped using radium, and if they ever used tritium or had some other compound (I have a 1966 model with crumbly lume dust but it doesn't look like radium at all).

I found no conclusive info, only reddit speculation and this unhelpful response from the Google AI, telling me Indigo™ was in use since the 60s.

[mbwatch]

"Indiglo™" that is. Thanks phone.

[AndyHull]

The trouble with AI is that it is not always very well informed.
For what its worth, Indiglo is a non radioactive dial illumination system.

Here is ChatGPT's take on Indiglo.
 

Quote

Timex Indiglo is a type of electroluminescent technology used in Timex watches to provide backlighting for the watch dial. It was introduced by Timex in 1992 and became one of the brand’s signature features.

Here’s how it works:

Electroluminescence: Indiglo uses an electroluminescent panel behind the watch dial. When activated, an electrical current passes through the material, causing it to emit a bright, even glow. This allows the entire dial to be illuminated, making it easy to read the time in low-light or dark conditions.

Activation: The backlight is typically activated by pressing a button on the side of the watch, often the crown or a dedicated button.

The Indiglo feature became extremely popular for its practicality and simplicity, and it remains one of the most recognizable aspects of Timex watches today. The technology has been applied to various Timex models, from analog to digital watches.

.. and with a little prompting, here is what it knows about Radium dials dumped by Timex Dundee.

Quote

Based on the documents from the National Records of Scotland, it appears that in 1949, the now-defunct Dundee firm UK Time, a forerunner to Timex, arranged a deal with local fishermen to dispose of 35,000 luminised dials coated with radium by dumping them in the Tay Estuary. This practice reportedly continued for another eight years, with an estimated 5,000 dials being dumped annually until the dumping was shifted to the UK's official disposal site at Beaufort’s Dyke.

So in other words, Timex dumped a lot of radium dials over an extended period into the Tay Estuary, the North Sea and ultimately into the Irish Sea/Celtic Sea/North Atlantic. As to how much of  hazard they actually pose, that is debatable. Not much, unless you happen to be extremely unlucky, and eat a fish that ate a lume flake that Timex made.

... and finally what it knows about Timex Tritium dials.

 

Quote

Yes, Timex, like many watch manufacturers, used tritium in some of its watch dials, particularly during the mid-20th century, after radium was phased out due to its health risks. Tritium is a radioactive isotope of hydrogen that was widely adopted as a safer alternative to radium for creating luminous watch dials.

Here’s how tritium was used in Timex watches:

Luminous Paint: Tritium was mixed with a phosphorescent material to create luminous paint. This paint would glow in the dark without needing exposure to light, allowing the watch dial and hands to be visible in low-light conditions.

Safety: Tritium is much less radioactive than radium and does not pose the same severe health risks because the radiation it emits (beta particles) cannot penetrate the skin. It was considered a safer option for luminescent watch dials.

Decline in Use: Over time, the use of tritium in watch dials has declined due to advancements in safer and more durable luminescent materials like Super-LumiNova, which are non-radioactive.

Tritium is still used in some modern watches, particularly in tactical or military timepieces, but its use is more regulated, and the amount of tritium used is much lower than in earlier decades.

This makes perfect sense. If you really want to know what was on your watch dial however, try measuring the activity with a geiger counter. Rather counter-intuitively if it is still quite "hot" then it is probably Radium, but if it is only sightly "hot", then it may be tritium, and if it doesn't even register, then it is probably one of the many non-radioactive luminous paints.

Also if it is still luminous, then it is probably not radium, as the zinc compound in radium dials is almost always spent, so they no longer light up. The radium on the other hand will be just about as radioactive as it ever was, so don't make the mistake of thinking that since it is no longer luminous, it is no longer radioactive, this is not the case.

Edited September 8, 2024 by AndyHull

[mbwatch]

The combined lume from their total 75000 dumped dials must work out to about three shot glasses full of radium paint. I have reached the stage where I do need to get a Geiger counter, while the lume on this particular dial does glow for about 3 seconds after hitting with a powerful UV light. On the other hand, it is only 58 years old as opposed to the spent and blackened radium dials from the 1940's I would never expect to glow at all.

On 9/8/2024 at 3:07 PM, AndyHull said:

Here’s how tritium was used in Timex watches:

It would be nice if ChatGPT supplied a source citation for literally any of its essay on Timex and tritium because it reads a lot like it gave you a description of what tritium is and how watch companies used it, decided Timex is a watch company and thus also used tritium.

On 9/8/2024 at 3:07 PM, AndyHull said:

The trouble with AI is that it is not always very well informed.

And the trouble with Google search as of a couple months ago is that you cannot perform one without it spouting the AI nonsense at the top. It's Indiglo blurb was a wrong response to a question I didn't ask, by a party I didn't want to hear from.

Edited September 9, 2024 by mbwatch

[AndyHull]

Don't ever loose sight of the fact that "artificial" can also mean "affected or insincere", and so long as you bear that in mind when reading the response of the likes of CharGPT, you are less likely to stray into the minefield of believing everything they come up with.

Edited September 9, 2024 by AndyHull

[mbwatch]

1 hour ago, AndyHull said:

Don't ever loose sight of the fact that "artificial" can also mean "affected or insincere

Tell me about it. My day job is in academic libraries where information literacy is being steamrolled gen-AI tools.

[AndyHull]

Quote

On two occasions I have been asked, "Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?" ... I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question.

— Charles Babbage, Passages from the Life of a Philosopher

Ever was it thus, it seems.