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  1. #11

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    Quote Originally Posted by RalphLambrecht View Post
    Dan, does that mean I'm creating fixer
    when trying to stop the toning?
    That's my understanding. Not very much though.
    Those brown toners are used very dilute. Likely the
    sulfur is an easy catch for the sulfite. The sulfur
    oxidizes the sulfite to a thio - sulfate. Dan

  2. #12

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    How long can I be saving HCA? I use the powdered kodak HCA packets and just use a tablespoon per liter and have been dumping after every session no matter how many prints I run through because I was told that it oxidized in a matter of hours. Am I wrong in dumping it or can I use it for a couple days? I'm switching to the Ilford Permawash liquid because its all I can get here soon but I still have one last packet of Kodak HCA.

  3. #13
    gainer's Avatar
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    You should be able to get sulfur at a druggist, or a farm supply store.

    What happened to the theory that HCA is worse than residual hypo? Maybe that was only for the formulae that contained peroxide.
    Gadget Gainer

  4. #14

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    Quote Originally Posted by gainer View Post
    You should be able to get sulfur at a druggist, or a farm supply store.

    What happened to the theory that HCA is worse than residual hypo? Maybe that was only for the formulae that contained peroxide.
    That theory wasn't about HCA (Kodak's Hypo Clearing Agent), Pat - it was about HE-1 (Kodak's Hypo Eliminator - which does contain Hydrogen Peroxide).
    Tom Hoskinson
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    Everything is analog - even digital :D

  5. #15
    Ian Grant's Avatar
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    Back to your original post I'm very surprised that you had any chemicals left in the paper, in 45 years of printing I've never seen what you are describing.

    As I said the chemicals used in wash aids / HCA are extremely soluble in water and wash out very easily.

    Only two things spring to mind, first the prints aren't being washed properly, maybe they are sticking together, or you have exceptionally hard water. I'm more inclined to go for the latter explanation.

    Oh I put a date on the washing in sea-water, perhaps I shouldn't have assumed WW2 :-)

    Ian


    Quote Originally Posted by RalphLambrecht View Post
    Thanks Ian

    This is not the reason for the thread,

  6. #16

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    Quote Originally Posted by rjas View Post
    How long can I be saving HCA? I was told
    that it oxidized in a matter of hours.
    It is that uncertainty with the usual sulfite based
    HCAs on the market that has me ready to switch to
    Agfa's recommended sodium carbonate based HCA.

    A study quoted in a post to rec.photo. darkroom
    recently told that sodium sulfite was, IIRC the exact
    words, "as good as any other". That is, not any better
    than some others. I suspect Agfa's recommended
    sodium carbonate is as good as sulfite and it
    does not oxidize. Agfa's instructions may
    still be on the WWW. Dan

  7. #17
    RalphLambrecht's Avatar
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    Ian

    It turned out to be the hard water. Thanks.
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  8. #18

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    Quote Originally Posted by dancqu View Post
    It is that uncertainty with the usual sulfite based
    HCAs on the market that has me ready to switch to
    Agfa's recommended sodium carbonate based HCA.

    A study quoted in a post to rec.photo. darkroom
    recently told that sodium sulfite was, IIRC the exact
    words, "as good as any other". That is, not any better
    than some others. I suspect Agfa's recommended
    sodium carbonate is as good as sulfite and it
    does not oxidize. Agfa's instructions may
    still be on the WWW. Dan
    However there are many posts on rec.photo.darkroom stating that sulphite is better than carbonate. I agree that carbonate is tempting since it is cheaper and used at a lower concentration and lasts longer in solution. It would be better than nothing.

    The Agfa pdfs might not be all findable on the web. I have some of them. FWIW, this text is cut from the most recent pdf on fibre paper:

    <start quote>
    Soda intermediate bath

    A soda bath (1 % sodium carbonate solution) should be included
    for fibre-base paper, between fixer and final wash (time: 3
    minutes). This ensures that the fixer is washed off the paper
    surface faster and more thoroughly.
    This not only cuts down the final washing time by about 30 %,
    and in particular it increases the prints' durability.
    If a hardener-fixer is used, the soda intermediate bath is not
    recommended.
    <end quote>

    In the unlikely event that hardening fixer is used, the carbonate is not recommended because its alkalinity would negate the hardening which is pH dependent. I wonder if the alkalinity would leave the paper emulsion softer which might make it vulnerable to some toning processes.

  9. #19
    Wolfgang Moersch's Avatar
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    Ralph

    If you prefer a low pH level HCA try this

    EDTA4Na 12g or DTPA pentasodium salt (solution) 25ml
    Sodium sulfite 200g
    Sodium bisulfite 6g
    Sodium citrate 4g

    to make 1000ml stock solution
    dilute 1+9 for working solution

    Wolfgang Moersch
    www.moersch-photochemie.de

  10. #20
    RalphLambrecht's Avatar
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    Quote Originally Posted by Wolfgang Moersch View Post
    Ralph

    If you prefer a low pH level HCA try this

    EDTA4Na 12g or DTPA pentasodium salt (solution) 25ml
    Sodium sulfite 200g
    Sodium bisulfite 6g
    Sodium citrate 4g

    to make 1000ml stock solution
    dilute 1+9 for working solution

    Wolfgang Moersch
    www.moersch-photochemie.de


    I didn't realize that much sodium sulfite would disolve in water. Couldn't you make this more me? I'm just on the other side of town.
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

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