Chernobyl Like radiation from my watch...!

ozmo

Ok - so I suspected some level of radiation from my watch when I realized it had a radium powered glow...

Is this normal though...? When I tested it tonight It’s off the scale! Has anyone else experienced this with their vintage watches?

https://www.youtube.com/watch?v=0COzYDQEfQc

Radium has a 1600 year half-life so it's certainly normal for an old radium dial watch to elicit such a response from a gieger counter.

There are potential health risks to owning such a watch, particularly the release of radon gas. They tend to be downplayed on watch forums.

Wibbs

Potential risks certainly. How potential is the thing. Those who would have been exposed the most to this stuff would have been watchmakers for a goodly portion of the 20th century. Opening and disassembling a watch carries significantly more exposure risk than wearing one. If your job entails opening and disassembling watches the exposure would be many times that of wearers. One of the biggest reasons radium was phased out was the concern about exposure for watchmakers. Taking that into account one would expect to see watchmakers having a beyond background level of illnesses that would come from radiation, but as far as I'm aware they don't/didn't?

Some watches have more radium applied than others. In the very early days around WW1 they fair lashed it on, by hand using paintbrushes(which did awful damage to the dial painters. QV Radium Girls). So much so that the phosphors that give the glow powered by the radiation would burn out pretty quickly. In some adverts from the time you see claims like two years glowing guaranteed. Which suggests some didn't last that long. Later on when the mixes were less active and mechanically applied the original glow would last many years. Aircraft clocks and dials are nearly always extremely strong emitters. They would concern me alright.

Of the watches I've had, the WW1 "Trench watches" were the most active and by a good measure(funny enough I'm wearing one today). WW2 stuff was well under half the output, more like a third. Economics came into it too as radium was expensive. The worst example I had is an early 30's Zenith Pilot's watch. Back in the 90's someone I knew was doing a college thing where she was measuring radiation sources in the average home. Things like smoke detectors have some active material. Antique glass wear another. They sometimes used uranium salts for colour. So I gave her my watch. A couple of days later I get a phonecall where she informs me that the dial and hands are very strong emitters. Can't recall the numbers, but I do recall her concern, describing it as low level nuclear waste. I decided to get it redialed and all the radium removed(family piece, so value be damned). You have to get the movements and case throughly cleaned too as it hides out there as dust.

That's another aspect with the stuff, it can ruin watches over time. The radiation can be strong enough to burn dials and if the crystal is plastic it'll cloud that too. On top of that it sucks up water like a thirsty camel. Which makes it break down even further, rotting hands and getting into the mechanism and causing wear. Another reason I wasn't so against retailing that Zenith. The original dial was in bits, barely legible.

Value comes into it. Collectors aim for 100% originality. Redialling/removing the radium from an early Rolex diver would seriously impact its value. My personal take on it is this: for WW2 and onwards watches I'm not too concerned. I wouldn't go licking the dials or anything. But having a couple of watches in rotation wouldn't be an issue for me. For early wristlets from the 10's, 20's I'd be more worried. In those examples with all but one(the one I'm wearing today) I've removed the radium from the porcelain dials and the hands and redid them with non radioactive lume.

EG, this 1914 Hampden.





The "trick" is to add some watercolour pigment in tiny amounts to get the colour correct as modern lume is bright white. With practice you can get it very close. EG in this WW2 issued navy watch one of the hands had lost 2/3rds of the lume so I feathered in some new.



What the original colour was is anyone's guess. Certainly for WW1 stuff. It's always brown after a century. Apparently it was originally white. I got a sealed bag of brand "new" replacement hands from the 1940's and some are a light sandy colour, while some are bright pale green. All radium.

The later tritium lume dials are far less a worry. The radiation emitted is lesser and of a kind(alpha and beta) that the case and crystal stops. Radium is a gamma ray emitter too and it goes through most things like a hot knife through butter. Though the WW1 watch I'm wearing today is a half hunter case, made from silver and with the lid closed the radiation is very much attenuated. I suppose silver is quite a dense metal so...

ozmo

Thanks for all the detailed replies- certainly hadn’t considered possibility of getting the face replaced or cleaned before...

I will put something together to display the actual rad level that you can hear in the video and update here

Wibbs

ozmo wrote: »

Thanks for all the detailed replies- certainly hadn’t considered possibility of getting the face replaced or cleaned before...

Well I've avoid a replacement dial as they rarely look as good as the original. With yours being a pocket watch the chances are high that it has a porcelain/enamel dial. Fantastic dials that look as good today as the day they were made and don't age anything like metal coated dials. They're far more resistant to radiation burning too. Their only disadvantage is that they're more delicate and can crack. They're also insanely expensive to produce today, so very few modern watches have them and those that do cost a lot. Even though the quality is barely on a par with even entry level dials from the early twentieth or nineteenth century examples.

The beauty with them in this context is that they can be cleaned of lume and can be relumed with non radioactive material. Hands can be cleaned too and the same non rad lume applied. That Hampden watch of mine above is an enamel dial. A near impossibility to do with printed metal dials. I've only ever had success with high gloss gilt dials. EG this WW2 Doxa.



Not found too often as these dials were/are pricey to produce. The original lume was horrible and had blackened the dial to near illegibility. I didn't redo the numerals with new lume as I'd never get it as good as the original printed type(the WW1 examples being originally hand done means another hand can do them). I did the hands though. Again colour matched them to examples of radium lume I've had/seen from that period. Though I suspect this Doxa's lume was originally pale green, or off white.

ozmo

So as promised - some more details of the levels I am reading...

Below is my test setup -


and I'm reading about 5,600 counts per minute - which translates to a radiation dose of 37-40 uS/h

For comparison (wikipedia)

from 5 to 100 μSv is just the one medical xray (depending on the type - dental is 5)


So you get the equivalent of an xray or two per hour by having the watch in your pocket

Wibbs

Pocket watches would appear to be a more risky source alright. Larger numerals and hands equals more lume and radium, plus you wear them close to the body, whereas wristwatches are generally, almost literally at arms length and radiation drops off with distance. The most active source I have is an altimeter from a Stuka dive bomber. A detector goes nuts at the face of it, at three feet away it's slightly above background, at six feet away it may as well not be in the room. That particular item I keep in a box in the shed.

Any chance of a pic of the watch face itself Oz?

Radon gas is the other thing to consider. Radium decays to radon, the chief cause of lung cancer for non-smokers.

For this reason radium dial watches should not be stored in a small or poorly ventilated room, due to the risk of elevated radon levels. This health risk has been generally underestimated in the watch community.

Certainly a collection (several) stored in a bedroom (where you spend 1/4-1/3 of your life) is something I would be legitimately concerned about. And that's not a particularly far-fetched scenario in the watch collecting community.

Wibbs

Deleted User wrote: »

This health risk has been generally underestimated in the watch community.

To be fair, since hard data on what the health risks are for wearing or having a radium dialled watch is impossible to find, under or overestimates are conjecture. Like I said, a near century of watchmakers who would have been exposed on a daily basis to open movements and dials didn't appear to raise flags in the medical world. Given the publicity in the early part of the 20th century around the Radium Girls, one might expect it would have come up?

Certainly a collection (several) stored in a bedroom (where you spend 1/4-1/3 of your life) is something I would be legitimately concerned about. And that's not a particularly far-fetched scenario in the watch collecting community.

Actually this is where I would agree with you. What has changed is the watch collecting hobby. It was a tiny niche hobby until the last twenty years(and especially in the last ten) when it exploded as a hobby. In say the 80's very few people would have had more than one watch and even fewer would have a collection of radium dialled watches. Today many more would. EG those who collect the "Dirty Dozen" of WW2 British issued watches.



All radium dialled. Originality is a must with these, so removing it not an option for collectors and no way in hell would I keep a set like that in a bedroom, or any room where I was staying in for hours at a time on the regular.

Wibbs

Wibbs wrote: »

To be fair, since hard data on what the health risks are for wearing or having a radium dialled watch is impossible to find, under or overestimates are conjecture. Like I said, a near century of watchmakers who would have been exposed on a daily basis to open movements and dials didn't appear to raise flags in the medical world. Given the publicity in the early part of the 20th century around the Radium Girls, one might expect it would have come up?

It's more so specifically the issue of radon gas that I was referring to (as being overlooked). It is rarely mentioned in these discussions. Everybody loves to whip out the geiger counter but I think the long term average radon readings in a small room with one or more radium-lume watches would be just as interesting (and perhaps concerning to the owner).

oxocube

Off topic but interesting none the less. I seen an Auction where the "dirty dozen" was up for sale. Starting price was £16K

Wibbs

Yeah the prices have gone nuts. At one time and not so long ago they were for the most part cheap watches. A couple of hundred quid for most of them. The expensive ones were the Longines, IWC and JLC examples, but even there were fairly affordable. IIRC it's the Grana that's now the dearest as they're the rarest by far.