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Re-Luming An Old Radium Dial To Restore Radio-Luminescence.

cdjswiss
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cdjswiss WRT Addict

cdjswiss

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Roland Ranfft is offering two re-luming pastes with excellent instructions on their use (as in Mark's video). One is based on the phosphor Zinc Sulphide (ZnS) , the other on Luminova.

http://www.ranfft.de/cgi-bin/bidfun.cgi?10&ranfft&b7&1usem&1456959600
http://www.ranfft.de/cgi-bin/bidfun.cgi?10&ranfft&b7&1usem&1456959601

These will glow for a few hours after exposure to sunlight (phosphorescence).

The early Radium luminous dials and hands glowed continuously due to the very long lifetime Alpha and Beta emission. Today an early Radium dial has no more radio-luminescence due to radiation damage to the phosphor (usually silver activated ZnS). But a dial with a good coating of old luminous paint (see below) can be brought to life again by applying a new overlay of ZnS.
I asked Ranfft to test this out and he found that non-activated ZnS applied over an old radio-luminous dial did glow even after several hours in the dark when the light-activated phosphorescence would have vanished. He also reported that Luminova was also activated in the same way but with more brightness than the ZnS.

Our conclusion is that if you have a radio-luminescent dial in good condition such as this one


post-374-0-89407700-1425839975_thumb.jpg

Then it could be brought to life again to glow all night long by the application of a layer of Luminova paste over the old numbers and hands. Silver activated ZnS paste would also perform well and be nearer to the original. Activated ZnS is available in small quantities from:

https://unitednuclear.com/index.php?main_page=product_info&cPath=16_17_69&products_id=218

If you do want to get into this game then buy a cheap (post Fukushima) radiation monitor from one of the Japanese eBay sources.
The above dial has a radiation dose rate above the crystal of 40 micro Sv/h. This is ample for a re-luming job.
 

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bobm12 Distinguished Member

bobm12

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Hi Colin,

 

Good to know! I'm planning on re-luming some stuff but I need to practice first on some hands in order to get it down pat before I attempt a dial. I'm saving the links for future use!

 

Cheers,

 

Bob

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cdjswiss WRT Addict

cdjswiss

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That's an enlightening post Colin, thanks for sharing. Are you going to re-activate the old Rolex lume?

Not until I have tried it out on this old Tudor Oyster that is even hotter at 65 micro Sv/h.

 

post-374-0-28766000-1425884748.jpg

 

I also wonder if it is only the hands of the Rolex that are active - the dial looks too good to be original.

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bobm12 Distinguished Member

bobm12

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I'll also be interested in the how-to of the whole thing. It seems like a super precise job: one little blink and the dial can go bye-bye! Also, Colin, be careful with the radioactive material. You never know with those, sometimes even a small amount could be a real hazard.

 

Cheers,

 

Bob

Edited by bobm12
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  • 7 months later...
Arny Member

Arny

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Posted

Thanks for the info

But

https://unitednuclea...products_id=218

On the LINK these people state that this stuff can be shipped anywhere,

BUT

First before you can purchase you have to be a member, you spend valuable time filling in

this ridiculous form with an address outside of the USA & Canada

It's then & only then they inform you that they only ship within the USA & Canada.

I have set a curse upon their webmaster

"I HOPE ALL HIS TEETH FALL OUT EXCEPT F­OR ONE, WHICH SHOULD REMAIN NONE REMOVA­BLE IN

ORDER TO GIVE Him SEVERE TOOTHACHE FOR THE REST OF HIS LI­FE. "

How do I load Pics?

Kind Regards

Tony (Arny)

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Arny Member

Arny

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I'm trying to edit my last post in order to remove my address, but I keep receiving this message (see pic)

HELP

After all its my post so surely I should be able to edit

Many Thanks in advance

Kind Regards

Tony

post-344-0-03055400-1444721798_thumb.jpe

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  • 3 months later...
cdjswiss WRT Addict

cdjswiss

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Thanks for bringing this post to life again with this link to Unitednuclear fluorescent paints. These are really no different than the others such as Luminova or the ones sold by Ranfft.

 

This is a point I still do not grasp: are all luming pastes, even the new ones, radioactive? Are the ones Ranfft sells radioactive?

 

Sorry George to be so late with a reply. The only radioactivity in everything that has been mentioned in this post is the very old residual radium paint on the dial and hands of vintage watches. The radium is still active but not the fluorescent material that was destroyed long ago by the radiation..

 

If a thin layer of  paint such as Luminova is applied over the old dial numbers or hands then it will glow because of the radium underneath, and this glow will be permanent lasting longer than the short-lived glow from exposure to light or ultra-violet rays (sunshine). This short-lived glow is phosphorescence caused by light, whereas the radium induced glow is usually called fluorescence.

 

In Tritium fluorescent watches (marked with a T on the dial) the radioactivity is from the Tritium gas that is contained together with the fluorescent material in glass micro-spheres. The radioactivity emitted by Tritium is low energy (penetrating power) and so it does not pass through the glass. If the glass spheres are ground down by accident the Tritium gas would just fly away presenting no hazard.

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