Fixer test

Discussion in 'B&W: Film, Paper, Chemistry' started by mrred, Jan 15, 2012.

  1. mrred

    mrred Subscriber

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    Lately I have been enjoying a lot of bw reversal processing. The last stage is still fix, as there are still small bits of undeveloped silver to be removed. In a perfect world, all remaining silver would be developed in the 2nd developer. Ordinarily exhaustion due to silver levels would dictate when the fix is done. I would imagine that it would be more likely spill over that would kill it now.

    How would I know when it is done? Is it a question of testing Ph?
     
  2. brucemuir

    brucemuir Member

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    Leader or clip test for clearing time.
    What type fix are you using?


    It matters because clearing times will be quite different if using an Ammonia or Sodium Thiosulphate based fix.
     
  3. johnielvis

    johnielvis Member

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    fix last a LOT longer with reversal--much less silver to get rid of---you'll kill your fix with 2nd developer carryover--I've extend the life of mine a LOT by using stop bath after the second dev...I test by putting a strip of undeveloped film (accidentally ruined stock that i keep for tests)....in the fix and time it....

    I was using regular hypo but switched to rapid fix too....I will still get rid of the fix after it has processed the "exhaustion" quantity as published....just to be safe, no matter if the clearing time is still quick (it usually is now with the stop bath)....