Pyrocat Question

Discussion in 'B&W: Film, Paper, Chemistry' started by dc1215, Feb 24, 2008.

  1. dc1215

    dc1215 Member

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    Hey everyone,

    So I ordered some new Pyrocat-HD from PF a few weeks ago in liquid form that thanks to the lovely New England weather and UPS, was left out in the cold all day, and ended up being frozen solid by the time I got home. It was only one of the bottles, I can't remember which one now though.

    So I processed some negatives in it anyways although I was a bit weary, and they came out, but they're much less contrasty than I would have expected. I usually use 2:2:100 for somewhere around 7 minutes with Delta 100. These negs need somewhere closer to 9 to be where they should be for my normal printing. I know the answer is just to get new developer and go back to my old routine, and I'm going to. I was just interested in the reason for this change. I'm assuming it was the freezing of it, but I still dont' know why beyond that. Any ideas? Any chance it was something else?
     
  2. gainer

    gainer Subscriber

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    Was it the water or the glycol mix? Either way, I can't see how freezing and thawing could do much if you were sure that there were no precipitated solids left. Surely some were precipitated because the solutions are pretty concentrated at room temp.
     
  3. lee

    lee Member

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    I don't know much about Delta 100 but I shoot FP4+ at half the box speed and at 68F 2:2:100 my time is 8,5 minutes.

    lee\c
     
  4. jgjbowen

    jgjbowen Member

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    Did you shake up solution B prior to mixing up the soup? I can't believe the Glycol based solution A would freeze.....
     
  5. dc1215

    dc1215 Member

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    I don't actually think it was solution A that froze, I think it was just B, but I'm not positive. I always shake it up and it thawed for 2 or 3 days before I even used it.

    I don't really care that my times are a bit longer now, I just thought it was strange that after a year and a half they suddenly changed, and the fact of the freezing just made it all seem a bit stranger. Like I said though I'm going to start fresh with some new developer and see what happens, I just wanted to see if anyone had any ideas.

    -Dan
     
  6. gainer

    gainer Subscriber

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    IIRC, pure glycol can freeze. There is a proportion of water to glycol where the freezing point is minimized. It's much like metal alloys. Tin and lead both have higher melting (freezing) points than their mixtures.