Selenium Toner batch life?

Discussion in 'B&W: Film, Paper, Chemistry' started by ToddB, Oct 16, 2013.

  1. ToddB

    ToddB Member

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    Hey guys, typically how long does a mixed batch of Selinium toner last before you have to toss it?

    ToddB
     
  2. Rafal Lukawiecki

    Rafal Lukawiecki Subscriber

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    Awfully long, if mixed with water (rather than with HCA). I've used 2-year old ones, whilst replenishing them in the past. Nowadays I don't do that, as I don't like having to filter the precipitate, so I replace when it is exhausted. If you search for posts by Doremus Scudder you should find his technique for replenishing it indefinitely.
     
  3. ROL

    ROL Member

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    In terms of absolute time, selenium toner lasts virtually indefinitely. However, in terms of the number, sizes and kinds of prints you run through it, you will find its effectiveness can wane rather dramatically, taking impractically long to your desired state of toning. Impurities can produce a scum which may adhere to the surface of prints in toner left to stand for long periods, and precipitated silver in well used toner can muck up the bottoms of trays.
     
  4. ToddB

    ToddB Member

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    Yes.. the floaties.. I didn't want to take any chances on that sticking to my prints. I tossed it. Thanks for insight

    ToddB
     
  5. Ian Grant

    Ian Grant Subscriber

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    You just filter it every so often. Then it lasts years, even decades.

    Ian
     
  6. Rudeofus

    Rudeofus Subscriber

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    Wouldn't the Thiosulfate oxidize eventually, at least in the working solution?