Actively seeking thorium mantles

Discussion in 'Pressure Lamp Discussion Forum' started by Neighbor Al, Nov 5, 2014.

  1. Neighbor Al

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    I'm actually seeking thorium mantles. I see vintage mantles on the bay, and wonder which (if any) were treated with thorium.

    Is anyone out there keeping track? I'd like to use them in my barn lanterns where the brightness would be handy, and there's plenty of ventilation.
     
  2. Primus 96

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    I have always wondered if there is great difference between using a thorium mantle or it's exact modern equivalent (in terms of light output) if tested on the very same lantern.
     
  3. Sedgman

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    Pretty much most mantles prior to 1991 contain Thorium 232 in the form of Thorium dioxide which is what remains when the rest of the mantle is initially burnt off. They are radioactive (0.0042 microcuries in some cases) and in tests I have done I had a geiger counter click over 500 clicks in 10 seconds compared to fluro tubes, a thoriated welding rod and other common sources of radioactivity which gave a max of 10 clicks in same period. I collect elements, their products and ores as a side hobby and I store all old mantles in a separate area. MSDS safety sheets say they are safe in common usage, but you should not breathe the dust from old mantles as the dangerous stuff stays in you! Some modern cheap 'nameless' type mantles that say they are not radioactive, actually are! They are often made in third world countries and I have had them tick over nicely with the counter. Tests done in the eighties showed that using them, say every second week in normal use will deliver you less radiation than normal background radiation which naturally exists around us, even in some nuts and common materials, e.g., some (but not all granite products). Frankly I would not go out to collect and use them in connection with lanterns because they are safety concern never-the-less. The element yttrium is what I believe major manufacturers now use to produce very safe mantles.
    Stay safe, use the non-radioactive mantles.
     
  4. dspearsy2k United States

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    checkout Post#21239. If you don't believe mantles make a big difference.
     
  5. ateallthepies

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    I'm really interested in the radioactive elements and recently read an article in which Thorium Mantles were mentioned which I had not seen before. It stated that after manufacture the radioactivity is not that bad but if stored for prolonged periods they become much more radioactive!

    This seems likely as the Thorium 232 decay chain includes several highly radioactive elements including probably most significantly Radium and it's daughter Radon which is a gas and can accumulate in enclosed places.

    Just how much Thorium with its crazy long half life turns into new elements at any given time I don't know, but is probably minute amounts and not much of a problem radioactively as long as the mantle stays outside the body?
     
  6. Cigarman

    Cigarman Subscriber

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    Peerless 1111 mantles use it. Liberty mantles do as well. (Have geiger counter, can confirm) Old coleman Silk Lites seem to as well. If memory serves, I could pick up Beta and Alpha with a small amount of Gamma. (need a spectrometer for that to be sure) Its the Alpha emitters that make me avoid the smoke when pre-burning them since you dont want those in your lungs. They sure burn bright though.

    Check these out for more education and learning:

    http://www.youtube.com/user/antiprotons
    http://www.youtube.com/user/bionerd23
     
  7. kero-scene

    kero-scene Subscriber

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    I've been quite interested in this topic for a while. The EPA in the US and ARPANZA in Oz have some good guidance on safety and thorium mantles. It's worth a good read if this is your hobby.

    I don't believe they are brighter, although I've never had the opportunity to compare side by side. Some years ago some scientists in Japan did some controlled experiments and, from memory, they did not identify an advantage in using thorium. If members are interested I'll dig out the reference.
     
  8. eiremax

    eiremax Subscriber

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    This bay be of some use to you. I have some of the old Auer Berlin 400-600 and Petromax 500 mantles.
    http://www.starklicht.com/app/download/5647397109/%C3%9Cbersicht-Gl%C3%BChstrumpftypen.pdf?t=1367531903
     
  9. Neighbor Al

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    Yes, thank you :)
     
  10. CaptainMIke R.I.P.

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    Hail all CPL members. One of my customers, named Tim Hall in West Virginia, checked over the Work Horse Brand mantles that I sell and found them too contain Thorium. I mention that in my listings, too. For the record, I really believe they are a much brighter white light than the others. Captain Mike in Hampton, Virginia trading as golmanschoice on Ebay.
     
  11. Primus 96

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    What is the situation in Europe & the UK regarding radioactive mantles? When was the use of Thorium banned? I had Anchor mantles that were radioactive this side of the Millenium. I cannot remember where I got the things from.
    The situation now may be different today, but I don't have any need for those.
    The stock I keep for my Petromax were alleged to be radioactive, being ex Bundeswehr spares. I should have them tested.

    Mantles were dipped with a mixture of Thorium & Cerium at a proportion of 99:1. Well that is what proportion the Welsbach company originally used.
    Whether this proportion ever shifted down the years I wouldn't know. It apparently has to do with producing the maximum visible light & the least infra-red.
     
  12. longilily

    longilily United Kingdom Subscriber

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    If the readings will mean anything to you, I can measure them for you

    Cheers
     

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