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  1. #1
    boy scout

    Two part developer - A+B blend!

    If there is a dilution of Pyrocat-HD I prefer using, is it alright to mix both parts A and B with X amount of water in one jug?

    I don't foresee any variation in temperature for the working solution, so to me - it seems okay!

    Any thoughts are greatly appreciated!

    Thank you!
    Last edited by boy scout; 01-04-2008 at 12:46 PM. Click to view previous post history. Reason: correction

  2. #2
    Andrew Moxom's Avatar
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    What specific pyro developer are you using?

  3. #3
    boy scout
    Quote Originally Posted by Andrew Moxom View Post
    What specific pyro developer are you using?
    Pyrocat-HD.

    In theory, I suppose it'd work just fine - but will it not keep very well? :o

  4. #4
    JBrunner's Avatar
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    If you are talking about making a working solution to store, the answer is, in general, NO. Once mixed, the A+B solutions of "normal" Pyro developers begin to oxidize fairly rapidly. You will be left with spent developer in short order, no matter if you use it or not. The normal tray life of Pyro is an hour or less, depending on formula, agitation, quantity, etc. Activated solution in a bottle would last longer I suppose, but would not last long enough, and not be stable enough, to be of any real use in most practical situations.

    If you are making a working solution to use in short order, sure, you gotta mix it in something. Curious what the alternative (other than a pitcher or graduate) would be.
    Last edited by JBrunner; 01-04-2008 at 12:55 PM. Click to view previous post history.

  5. #5
    Snapshot's Avatar
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    I found that when I mixed pyro solutions A & B together, oxidation began almost immediately. Do you plan to store your developer for a period of time? If so, then you'll find it exhausted in short order.
    "The secret to life is to keep your mind full and your bowels empty. Unfortunately, the converse is true for most people."

  6. #6
    JBrunner's Avatar
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    I see you amended your post to include that you are using Pyrocat. Pyrocat is more stable and lasts a bit longer than Pyrogallol, and can be used more easily in rolling development, but it my earlier post still applies. These are rapidly oxidizing developers, once activated.

    In the two part solution, they keep very well.

  7. #7
    boy scout
    It's only a one gallon jug and I plan to blow through it in less than a week!

    When Pyro oxidizes, I don't suppose it'll change colors or viscosity? Haha...

    Guess I'll just have to separate the two solutions then!

  8. #8
    JBrunner's Avatar
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    Quote Originally Posted by boy scout View Post
    It's only a one gallon jug and I plan to blow through it in less than a week!

    When Pyro oxidizes, I don't suppose it'll change colors or viscosity? Haha...

    Guess I'll just have to separate the two solutions then!
    Pyro turns brown when oxidized, although it may take on the color of your film backing when you use it, especially if you don't pre wet. Also, you will need to blow through it in a couple of hours.
    You ain't gonna get a day, let alone a week. Also developer activity, and thus your negatives, over the few hours, will be very inconsistent as activity falls off.

    Pyro needs to be mixed fresh, for each tank or tray development, and used one shot.

    It ain't hc110.
    Last edited by JBrunner; 01-04-2008 at 07:39 PM. Click to view previous post history.

  9. #9
    JBrunner's Avatar
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    ".....and that's the photo news for today. Now lets take a look at tomorrows processing forecast with J Brunner, J?

    "Thanks Phil, tomorrow's forecast is for the thin negs of this evening to be followed by blank ones, with a pinkish tinge, in the morning. Afternoon gnashings may occur. Back to you, Phil.



 

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