Dead chemistry results during drying

Discussion in 'B&W: Film, Paper, Chemistry' started by Ottrdaemmerung, Aug 7, 2011.

  1. Ottrdaemmerung

    Ottrdaemmerung Member

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    Hi, folks. I've just gotten started doing printing and am feeling my way about the darkroom. I just did a long printing session last night and I KNOW the pitiful one liter of chemistry per chemical (for 11x14" trays) was not nearly enough to get good results, and they were dying on me fast. When I stopped, nearly all the chemicals were an orange color. Yeah, that made me wince. And some of my last printing efforts are tainted by yellowed edges.

    The purpose of this post is not for you guys to beat me up over using exhausted chemistry, but because I'm curious about something. The guy who sold me my enlarger threw in a drying rack he had built , and he sandwiched his prints between large metal window screens for drying. I dried my work (some FB, some RC) face down between those same screens, and several of my prints --all of them 11x14 -- had small (1/4" around) chemical splotches on them in random places, and they had bits of white crosshatching in random places, obviously caused from contact with the screen.

    I'm wondering if these white artifacts are from improper fixing, hypo-clearing, or washing. If so, when I start using fresh chemistry in more generous amounts, will I still have to worry about the screens imparting patterns on my prints?

    Any other general tips would be appreciated - like I said, I'm just starting with printing and I'm loving it. I just hope to get spotless results. Thanks!
     
  2. DWThomas

    DWThomas Subscriber

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    I am a bit surprised at the use of metal screening -- if I were doing my own rack I think I would use some of the fiberglass/plastic stuff. I would think metals could contribute some chemical action in contact with wet prints.

    A liter is a bit small for 11 x 14. Developers head toward brown as they oxidize from exposure to air, as well as exhaustion. Stop bath is normally yellow if you use the indicator stuff. And that drags over to the fixer to some extent, so that could be the orange look there.

    I only do rare small sessions, so I don't have any numbers in mind, but you might want to dig up numbers on fixer capacity in particular, as 11 x 14 is a goodly sized chunk of emulsion.
     
  3. Bob Carnie

    Bob Carnie Subscriber

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    you need to clean the racks with hot water, they sound contaminated.. FYI when I am printing I use 20 x24 trays with 10 litres of working solution so that I can print all day.
     
  4. Mike Crawford

    Mike Crawford Member

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    Hello

    The screens are not the metal hinged type used for screen printing by any chance? If so maybe not so good for photographic prints, though you could use sheets of acid free blotting paper on the racks so the prints are drying on a more friendly base. I get mine in bulk from art material suppliers and they're pretty cheap.
     
  5. MattKing

    MattKing Subscriber

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    I wouldn't use screens for the front of RC prints.

    If the stop bath is indicator stop, it normally turns blue when it exhausts. You could probably have just diluted it a bit to have it work fine.

    It might be worthwhile to try re-fixing the prints and then re-washing them. For the FB ones, I'd suggest a wah aid as well.
     
  6. Gerald C Koch

    Gerald C Koch Member

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    I would keep the prints face up during drying. Should they curl a bit, the dry prints can be put under a large weight for a couple of days to flatten them. The screens should be rinsed after each use and periodically gently scrubbed using a mild detergent. Plastic screen is better than metal.
     
  7. tj01

    tj01 Member

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    The fixer shouldn't be coloured, unless it's contaminated from the developer. If you use water stopbatch, change frequently and use plenty.
    The discolouring on your print edges should be inadequate fixer. Either do a two bath fixing, or discard after use, don't reuse.
    Have fun