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  1. #21
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    I would be a little leary about Kosher salt for photographic use. It is my understanding that Kosher means approved and blessed by a Rabbi for human consumption in accordance with certain principles that do not necessarily preclude the presence of iododes or other naturally occurring substances, so long as they are not harmful to humans. I'm pretty sure a thorough chemical analysis is not necessary, though I do not know the actual rules. The Law is much older than the chemistry. A better choice would be canning salt IMO.
    Gadget Gainer

  2. #22

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    Quote Originally Posted by gainer View Post
    I would be a little leary about Kosher salt for photographic use. It is my understanding that Kosher means approved and blessed by a Rabbi for human consumption in accordance with certain principles that do not necessarily preclude the presence of iododes or other naturally occurring substances, so long as they are not harmful to humans. I'm pretty sure a thorough chemical analysis is not necessary, though I do not know the actual rules. The Law is much older than the chemistry. A better choice would be canning salt IMO.
    Correct. Some brands of Kosher salt have something called "yellow prussiate of soda" included to prevent the salt from caking up. Other brands are nothing but pure sodium chloride. If you check the labels, it should tell you.

  3. #23
    Ole
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    Quote Originally Posted by fschifano View Post
    ... something called "yellow prussiate of soda" ...
    Isn't that sodium ferrocyanate? If so, that's exactly what you don't want to mix with potassium ferricyanate!
    -- Ole Tjugen, Luddite Elitist
    Norway

  4. #24

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    Quote Originally Posted by phritz phantom View Post
    so, i finally found out that "hypo" does not mean "hypo clearing agent", but "sodium thiosulfate".
    i was wondering for a long time, why some people mix bleach with fixer and others with hypo. thanks a lot for clearing that up.

    but....
    all the fixers i use don't contain "sodium thiosulfate". they contain "ammonium thiosulfate". is there a difference between those two chemicals when mixing it with potassium ferricyanide? or can i keep using the amm. thios. fixers?
    Amm thiosulphate is 'rapid fixer'. It works fine with bleach too - but you will find that the ferri activity is short lasting (yellow colour goes too) and the mix needs topping up with PF as you go along.
    Tim

  5. #25

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    Quote Originally Posted by gainer View Post
    I would be a little leary about Kosher salt for photographic use. It is my understanding that Kosher means approved and blessed by a Rabbi for human consumption in accordance with certain principles that do not necessarily preclude the presence of iododes or other naturally occurring substances,
    Thank you for that. I was under the impression that it was without the iodide that was added to normal table salt in the US.
    Good to know these things ;-)

  6. #26

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    Quote Originally Posted by tim rudman View Post
    Amm thiosulphate is 'rapid fixer'. It works fine with bleach too - but you will find that the ferri activity is short lasting (yellow colour goes too) and the mix needs topping up with PF as you go along.
    Tim
    thanks for the answer.
    i noticed that before. when the yellow colour turns blue-ish/turquoise, it's exhausted. doesn't take long usually, 10 - 15 minutes for appr. 50ml.

  7. #27

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    another question:
    is somebody successfully using pot.ferri bleach with rc-papers?
    are paper especially suitable?

    i've only tried maco multispeed paper so far and it only responded to very strong solutions and gave a very ugly brown tone.

  8. #28

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    Quote Originally Posted by phritz phantom View Post
    another question:
    is somebody successfully using pot.ferri bleach with rc-papers?
    are paper especially suitable?

    i've only tried maco multispeed paper so far and it only responded to very strong solutions and gave a very ugly brown tone.
    Any emulsion (containing metallic silver ) will bleach in PF or PF/BR etc.
    From a practical point of view I find that for local 'lightening' with 'liquid sunshine' that I get better results with FB than with RC (- but then I rarely use RC.) with less staining, more control etc.
    For bleach & redevelop either works well.
    Tim

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