RA-4 Chemistry

Discussion in 'Color: Film, Paper, and Chemistry' started by nlochner, Jun 20, 2006.

  1. nlochner

    nlochner Member

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    i have been working with RA-4 for only a mont now, and was wondering if it is very dangerous. Also, i just bought a 10 liter kit, and only want to make 1 liter at a time, so i divided everything by ten, including the water you add. Will this still work.
     
  2. Ed Sukach

    Ed Sukach Member

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    No, it isn't. I wouldn't drink the stuff, but - read the instruction sheet... it seems to contain sufficient safety information.

    Yes, it will.

    I think it is important to store the unused chemistry properly, to prevent oxidization. A shot of propane - or as I do, butane from a BernzoMatic Mini Torch into the bottles to displace air - has worked - very well.
     
  3. srs5694

    srs5694 Member

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    Several different manufacturers make RA-4 chemistry (or perhaps technically that should be "RA-4-compatible chemistry" for most manufacturers). They don't seem to be absolutely identical. If nothing else, some (such as Tetenal and Paterson) ship the developer and blix both in single bottles, pre-mixed, to be diluted for use; others, such as Kodak and Freestyle's house brand, ship in multiple bottles that you mix together and add water for use. I don't know if these differences are important for either safety or keeping properties -- any comments on this? I do know that the instructions I've read all give different keeping properties for mixed/diluted vs. unmixed/undiluted storage.
     
  4. Chan Tran

    Chan Tran Member

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    For many years I used Kodak RA-4 and I found that they are pretty harmless. I recently tried some Tetenal and found that their blix is a bit more caustic.
     
  5. Ed Sukach

    Ed Sukach Member

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    I'm sure that the accomplished Chemists we have here on APUG can give a more well defined answer than I can - but from my observations, the multiple component color developers and blix last longer, protective gas blanket or not. I have purchased NEW kits with unopened bottles containing oxidized -shot- (characterized by thick, black concentrates) chemistry - and *most* have been of the "single concentrate" variety.

    True - the concentrates will last *much* longer than working solutions.

    BTW - Paterson and Tetenal BOTH produce "multiple component" chemistry.
     
  6. Ed Sukach

    Ed Sukach Member

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    Interesting!!!

    How did you arrive at that conclusion?
     
  7. Chan Tran

    Chan Tran Member

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    You may call me stupid but I got them on my hands at times. I never felt anything with the Kodak but the Tetenal it did irritate me.