Replenished D-76: Is Gray OK?

Discussion in 'B&W: Film, Paper, Chemistry' started by Snapshot, Jan 19, 2008.

  1. Snapshot

    Snapshot Member

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    Hi All,

    After using D-76 in a replenished system for a few rolls, I'm finding that the stock solution turns a cloudy gray. However, I'm not seeing in performance degradation in development. Does anyone have any explanation as to what the coloration could be due to? I personally believe the cloudy gray coloration is due to colloidal silver.

    Any thoughts?
     
  2. gainer

    gainer Subscriber

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    I used to do that. The gray is IMO suspended silver particles. Given enough time, they will settle. I used the stuff until I began to feel guilty about the color, then mixed a new stock. Old custom was to add a certain proportion of "seasoned" stock to the new batch. Part of the change when using replenishment is the build up of bromide in solution. This was actually considered desirable in those days up to a point. If the particles get to be bigger than colloidal, you can filter the solution, but those should settle fairly rapidly. Just don't stir them up when you pour into the tank. Replenishment was used mostly in large tanks for sheet film in hangers, where there was no pouring from one container to another. Quite a sludge could accumulate at the bottom before a new batch would be mixed.
     
  3. Ian Grant

    Ian Grant Subscriber

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    It's fine & quite normal. Like Gadget says you can filter it out if you ant.

    Ian
     
  4. Snapshot

    Snapshot Member

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    Glad to hear that this is not unusual. Thank-you for your input gentlemen.