Radium Dial Question

[mjolnir2thor]

Greetings watch buds!

I've been doing some reading about Rolex dials and the use of Radium as a source of illumination on the submariner. From what I have learned, radium was used until 1962 where they then began using a less radioactive mixture. These Rolex dials (circa 1962 to 1963) were identified with a dot or a silver underline on the face of the watch. See link to article below:

https://magazine.bulangandsons.com/t...bmariner-7928/

So being a newbie, my questions are...

1. Are the radium timepeices a safety concern and should be avoided for daily casual wear?
2. For those transition models (e.g., underline/dot dials) is there a safety issuing with these timepieces? I would think the potential risk is less given the lower radiation level.

As always, your input/comments are appreciated.

[Dan S]

People don't agree on this because it's a matter of personal risk tolerance. However, there are dozens of threads on the forum, to you can read a lot of opinions, as well as essays about the penetration of alpha/beta/gamma particles, the associated risks of radon gas, etc. My impression is that the majority of vintage collectors aren't concerned about it, but there is obviously a lot of selection bias involved. And then occasionally you will run into someone who says that they have small children in the house, and any risk is too high, no matter how small.

Personally, as a scientist, I take an empirical approach, and I own a Geiger counter and radon meter to check ambient levels in my surroundings.

[mjolnir2thor]

Originally Posted by Dan S

People don't agree on this because it's a matter of personal risk tolerance. However, there are dozens of threads on the forum, to you can read a lot of opinions, as well as essays about the penetration of alpha/beta/gamma particles, the associated risks of radon gas, etc. My impression is that the majority of vintage collectors aren't concerned about it, but there is obviously a lot of selection bias involved. And then occasionally you will run into someone who says that they have small children in the house, and any risk is too high, no matter how small.

Personally, as a scientist, I take an empirical approach, and I own a Geiger counter and radon meter to check ambient levels in my surroundings.

Thanks Dan for the reply.

Since I've started the thread this morning I've been doing a bit more reading on the topic. You're right, there are many different opinions on this topic. The reason I ask is that I would like to casually wear a vintage Sub (no water or diving) as a daily wear item and trying to sort out what would be a cut off point in terms of year.

From what I am concluding so far is that I think I will avoid a radium dialed watch. However, I have seen a few 1962/1963 vintage Subs where I would love to find/have a pristine example provide there is no issue with the lume on a transitional (i.e., underline) dial.

My understanding is that these transitional watches have a lower level of radioactivity. I guess the easiest thing to do is to get a geiger counter to see the radiation level per individual watch.

It'll be interesting to see what folks in the forum think. Thanks again for your response.

[Dan S]

Originally Posted by mjolnir2thor

My understanding is that these transitional watches have a lower level of radioactivity.

This is true. Higher than 0.25, but substantially lower than 50s Subs.

[mjolnir2thor]

Does anyone know if there is a visual way to tell? Would a Radium dial glow (to some degree) no matter the age since the shelf life of radium is 1600 years from what I have read? Anyone have any experience with a radium dial who can provide input?

Tritium has a 12 year half life. I know if you activate the tritium under UV light, it will glow for a few seconds. Is it the same with radium?

[TimeLord2]

I read that one of the main concerns was not so much the radiation from the watch itself but to those workers who applied the Radium to the watch face.

[mjolnir2thor]

Originally Posted by TimeLord2

I read that one of the main concerns was not so much the radiation from the watch itself but to those workers who applied the Radium to the watch face.

There is an excellent video on YouTube from the Horological Society of NY. It's lecture by Kathleen McGivney from 2017. I find it very interesting and educational.

Link below...

https://www.youtube.com/watch?v=3Kew04Qgc1I&t=8s

[Dan S]

The "glowing" under UV excitation is pretty much irrelevant because that is associated with the phosphor, not the radium or tritium. Phosphors also degrade over time, and different phosphors behave differently. That's what you are testing with UV excitation, not the radioactive component that "powers" the phosphor.

It's not expensive to buy a consumer grade Geiger counter. That will address your questions once and for all.

[mjolnir2thor]

Originally Posted by Dan S

The "glowing" under UV excitation is pretty much irrelevant because that is associated with the phosphor, not the radium or tritium. Phosphors also degrade over time, and different phosphors behave differently. That's what you are testing with UV excitation, not the radioactive component that "powers" the phosphor.

It's not expensive to buy a consumer grade Geiger counter. That will address your questions once and for all.

Going to buy one as you suggest. Only way to know for sure.

Under UV light Radium versus tritium acts differently when the UV light is turned off. Fast forward to about 39 minutes in the video where she does just that... exposes a radium, tritium and super lumina dial to UV light and then shuts off the light. The radium goes out immediately.

Great video and highly recommended by the newbie (me)

[Dan S]

Originally Posted by mjolnir2thor

Going to buy one as you suggest. Only way to know for sure.

Under UV light Radium versus tritium acts differently when the UV light is turned off. Fast forward to about 39 minutes in the video where she does just that... exposes a radium, tritium and super lumina dial to UV light and then shuts off the light. The radium goes out immediately.

Great video and highly recommended by the newbie (me)

Radiation from radium definitely does tend to degrade the phosphor more than tritium, so there is probably truth to some of this. However, it is greatly oversimplified. For example, the response of the tritiated lume will depend greatly on the details of the formulation. Just compare the response of tritium lume from a 1967 Sub, a 1972 Sub, and a 1978 Sub. They will all be different because of the different phosphors that were used, not the age.

So watch videos, read the forum, and learn, but be skeptical and keep an open mind. It will take you years to learn all the nuances.

Regarding Geiger counters, they are very good for comparing radiation from different sources measured under similar conditions. However, it can be notoriously difficult to compare absolute radiation measurements from one brand of counter to another. So don't expect that you will get the exact same value as you see on the internet. And once you get a counter, it will be helpful for you to get your hands on a sampling of watches with different types and amounts of lume. That will help calibrate your expectations.

[mjolnir2thor]

Originally Posted by Dan S

Radiation from radium definitely does tend to degrade the phosphor more than tritium, so there is probably truth to some of this. However, it is greatly oversimplified. For example, the response of the tritiated lume will depend greatly on the details of the formulation. Just compare the response of tritium lume from a 1967 Sub, a 1972 Sub, and a 1978 Sub. They will all be different because of the different phosphors that were used, not the age.

So watch videos, read the forum, and learn, but be skeptical and keep an open mind. It will take you years to learn all the nuances.

Regarding Geiger counters, they are very good for comparing radiation from different sources measured under similar conditions. However, it can be notoriously difficult to compare absolute radiation measurements from one brand of counter to another. So don't expect that you will get the exact same value as you see on the internet. And once you get a counter, it will be helpful for you to get your hands on a sampling of watches with different types and amounts of lume. That will help calibrate your expectations.

Thanks Dan... excellent advice.

[harry in montreal]

I owned a 61 Tudor sub with an exclamation point dial. It was really nice but I could just not wear it. It always felt fragile and I have a lot of relatives with cancer. Likely no more dangerous than appliances in my home I just felt more comfortable selling it and buying two 70s tritium subs. No regrets. Saved $200 on a Geiger counter too.

[mjolnir2thor]

Just some more interesting information found online at Rolex Haven. If these are posted elsewhere on RF site, my apologies. Thought I'd share as I learn and compile information as a novice.

Luminous Material:

https://rolexhaven.com/luminous-material.html

Geiger Counter Readings: (interesting comparisons)

https://rolexhaven.com/geiger-readings.html

Folks, please feel free comment in the thread as appropriate...

[mjolnir2thor]

Originally Posted by harry in montreal

I owned a 61 Tudor sub with an exclamation point dial. It was really nice but I could just not wear it. It always felt fragile and I have a lot of relatives with cancer. Likely no more dangerous than appliances in my home I just felt more comfortable selling it and buying two 70s tritium subs. No regrets. Saved $200 on a Geiger counter too.

So far what I have learned, the geiger is the only way to truly know. At this point I am thinking that a 5513 from 1963 forward is my threshold for risk. I'm not comfortable wearing a timepiece older than 1963 at this point. If I end up buying a 5513 in the 1963 (later the better), I will surely test with a geiger.

Thanks everyone for your guidance and input.

[harry in montreal]

Well, the 63-66 5513s are just beautiful. It’s a great choice. Post 66 thé dials are not gilt and the inserts are less oft Long 5.
Ive never tested my 63-70 watches. Maybe I will buy a Geiger and see what transpires.

[mjolnir2thor]

Originally Posted by harry in montreal

Well, the 63-66 5513s are just beautiful. It’s a great choice. Post 66 thé dials are not gilt and the inserts are less oft Long 5.
Ive never tested my 63-70 watches. Maybe I will buy a Geiger and see what transpires.

It's been quite an educational experience so far and I've enjoyed going down a few rabbit holes. The year range you describe (63 - 66) would be ideal!

[harry in montreal]

With the money you have saved buy a 16600 sea dweller from 2000-2005. This is my favorite heavy duty Rolex. Just a sick watch. Thé 5513 is like wearing a little work of art on your hand

[007Sub]

Originally Posted by mjolnir2thor

It's been quite an educational experience so far and I've enjoyed going down a few rabbit holes. The year range you describe (63 - 66) would be ideal!

Its precisely for this reason my favorite gilt era is 63-65.
66 is nice also but in 65 forward they no longer used the gilt hands as well. In any case, you have all the charm of gilt dials without the radioactivity.

[mjolnir2thor]

Originally Posted by harry in montreal

With the money you have saved buy a 16600 sea dweller from 2000-2005. This is my favorite heavy duty Rolex. Just a sick watch. Thé 5513 is like wearing a little work of art on your hand

The SD 16600 is an outstanding timepiece and the last of the aluminum bezeled SD. However, I’m looking for that little work of art on my wrist at this point. I had a 1967 meters first 5513 years ago and should have kept it but didn’t.

I really miss the charm of the older Sub and the way in which it wore.

[mjolnir2thor]

Originally Posted by 007Sub

Its precisely for this reason my favorite gilt era is 63-65.
66 is nice also but in 65 forward they no longer used the gilt hands as well. In any case, you have all the charm of gilt dials without the radioactivity.

After reading, watching videos, etc. that was the conclusion I came to as well.

[brandrea]

Originally Posted by mjolnir2thor

The SD 16600 is an outstanding timepiece and the last of the aluminum bezeled SD. However, I’m looking for that little work of art on my wrist at this point. I had a 1967 meters first 5513 years ago and should have kept it but didn’t.

I really miss the charm of the older Sub and the way in which it wore.

Too funny. You and I share the exact same experience.

My first Rolex was a 16600. I wore that thing for 15 years and stupidly sold it.

Then, I bought a 5513 (caseback stamped 66, but serial number was 1.7M so might have been a 67. I sold it on just before the boom in price

[mjolnir2thor]

Originally Posted by brandrea

Too funny. You and I share the exact same experience.

My first Rolex was a 16600. I wore that thing for 15 years and stupidly sold it.

Then, I bought a 5513 (caseback stamped 66, but serial number was 1.7M so might have been a 67. I sold it on just before the boom in price

It has to be a rite of passage for a vintage horological enthusiast!

[brandrea]

Originally Posted by mjolnir2thor

It has to be a rite of passage for a vintage horological enthusiast!

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[LateLearner]

My Radex RD1503, was $100, on Amazon. It reads to a maximum of 9.99 microseiverts per hour.

This should be enough for early 1960s dials. You may need a better, more expensive Geiger, capable of readings higher than 9.99, for older watches.

Well worth the small investment for a pricey hobby, even if you don’t buy a radium watch.


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[LateLearner]

You DON’T want to see this on a 1965 Sub 5513.


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[mjolnir2thor]

Originally Posted by LateLearner

My Radex RD1503, was $100, on Amazon. It reads to a maximum of 9.99 microseiverts per hour.

This should be enough for early 1960s dials. You may need a better, more expensive Geiger, capable of readings higher than 9.99, for older watches.

Well worth the small investment for a pricey hobby, even if you don’t buy a radium watch.


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Was just on Amazon looking for the same Geiger Counter but it is listed for $303, although a plus version! How long ago did you purchase it?

I ended up buying the GQ 600-GC GMC-600 Alpha Geiger Counter Radiation Detector Dosimeter Alpha Beta Gamma X-Ray Tube SBT-11. I figured it would be a good thing to have in the home beyond using it for the watches.

https://www.amazon.com/GQ-600-GC-Rad...ustomerReviews

[mjolnir2thor]

Originally Posted by LateLearner

You DON’T want to see this on a 1965 Sub 5513.


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Whoa!!!

How is that possible on a 1965 Sub? I thought the manufacturing process switched to tritium by this point?

[LateLearner]

The tritium dial was relumed in the late 60s or early 70s with radium. The radium was applied on top of the tritium.

I had no idea for the nearly 30 years I wore it day and night until earlier this year.

Earlier this year the radium was removed and was relumed with old tritium, matching hands/dial.

Now, it reads 0.38 microseiverts per hour, or so.


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[mjolnir2thor]

Originally Posted by LateLearner

The tritium dial was relumed in the late 60s or early 70s with radium. The radium was applied on top of the tritium.

I had no idea for the nearly 30 years I wore it day and night until earlier this year.

Earlier this year the radium was removed and was relumed with old tritium, matching hands/dial.

Now, it reads 0.38 microseiverts per hour, or so.


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That's an incredible story... who would have thought this could have happened! Glad you are okay!!!

From what I read, as long as the case is sealed, the case back prevents the radiation from reaching the wrist. If you haven't seen it, you might want to take a look at the link I posted where Kathleen McGivney give a nice lecture on radium dialed watches. I think I would have done exactly what you did by having the radium removed and the tritium lume re-applied.

[LateLearner]

Originally Posted by mjolnir2thor

That's an incredible story... who would have thought this could have happened! Glad you are okay!!!

From what I read, as long as the case is sealed, the case back prevents the radiation from reaching the wrist. If you haven't seen it, you might want to take a look at the link I posted where Kathleen McGivney give a nice lecture on radium dialed watches. I think I would have done exactly what you did by having the radium removed and the tritium lume re-applied.

I inherited the Sub, and chronicled this odyssey on VRF, under the thread “Sorriest Relume Ever” this past spring. There are “before” and “after” pics. My account on VRF is IIIQTR65SUB5513.

While I wouldn’t have knowingly worn it with radium, exposure wasn’t “whole body” or ingested. The highest reading is through the crystal, which is obviously directed away from the body. Readings on the case back were a fraction of the crystal.

Readings taken even an inch away (or on the side of the case) dropped off by half, or more. A couple inches away were the same as room readings. To use a ballistic term, the maximum effective range was minimal.


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