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  1. #21

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    Quote Originally Posted by Aggie

    Yes a toxic gas can be given off from this compound if it is mixed with a strong (HCL or hyrdrochloric acid) acid.
    Excellent Aggie - hope your reply kills this thread.

    Happysnapper - don't eat the potassium ferricyanide. HCl is an important constituent of your digestive juices.

    Bear Down, Arizona!
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  2. #22
    Ole
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    Yes, HCN (Hydrogen Cyanide) is a very toxic gas. If you ever feel the smell of almonds when toning, you should already have run away.

    But remember that H2S (Hydrogen Sulfide), the nasty smell of sulfide toner, is 100 times more toxic - and far easier to make. Keep all toners away from acids!
    -- Ole Tjugen, Luddite Elitist
    Norway

  3. #23
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    I have an overexposed neg I would like to try it on. I bought Kodak "Farmer's Reducer" (I would love to know where the name comes from);

    Question: if the PF ("Part A" ) is all you need, what is the point of their "Part B"?



    As far as toxicity, the professor suggest not sniffing the powder, and I agree. I was sniffing for a while, butI have graduated to injecting it and I feel great.

  4. #24
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    quick clarification for those that do not understand about an opaque white piece of plexiglass. When a light source from behind it is turned on, the plexiglas glows from the light. this allows the picture to be gently illuminated for the purposes of bleaching. A translucent sheet would give way to much light and the light around the edges would interfere while looking at the picture. So Yes I do mean opaque.

    This is the sheet of material that I purchased and the company I bought it from.


    http://www.tapplastics.com/shop/product.php?pid=258&sed
    Last edited by Aggie; 07-25-2004 at 11:37 PM. Click to view previous post history.

  5. #25
    ann
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    mobtown;
    part b in Farmer's reducer is typical sodium thiosulfate (hypo). I haven't used pre-package for years and since i don't have the package in front of me i will not guarantee that is what yours is;but i would be surprised if it wasn't hypo.

  6. #26
    ann
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    forgot to answer your question about why. the ferri converts the silver to another form (silver ferricyanide) and the hypo clears the ferri.

  7. #27

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    A couple quick comments.

    The white plexiglass that Aggie describes is a common material in commercial backlit signs. Any medium to large city will have a plastics supplier who will cut a piece to the size you want, saving you the cost of shipping.

    If you are gong to bleach an entire print I have found that it is important to use a large tray and agitate very gently by moving the solution over the top of the print with brush while not touching the print. If you rock the tray you will get excessive bleaching in the corners of the print where the solution backflows from the corners of the tray.
    "Fundamentally I think we need to rediscover a non-ironic world"
    Robert Adams

  8. #28
    mobtown_4x5's Avatar
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    thanks Ann, that makes sense.

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