Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,279   Posts: 1,534,853   Online: 739
      
Page 1 of 2 12 LastLast
Results 1 to 10 of 11
  1. #1
    kb3lms's Avatar
    Join Date
    Jun 2006
    Location
    Reading, PA USA
    Shooter
    35mm
    Posts
    696
    Images
    5

    RA-4 Kodak RA-RT Lifetime

    I have been room temperature tray processing a number of 8 x 10 and 10 x 12 prints in Kodak RA-RT chemistry using a developing time of two minutes. The liter I am working with right now has had 22 or 23 prints (mostly 8x10) run through it and the contrast of the prints has started to rise quickly with the colors starting to look a little "plastic". The first 20 prints looked OK. Is this an indication that the developer or blix is reaching exhaustion? The paper I am using is Kodak Royal "Digital." It's been working well till this contrast issue came up in the last three or four prints.

    As a test I went back and printed a small piece of Edge and it has the same higher contrast.

    Is it worthwhile to add a pinch of sulfite to try and extend the life of this batch or just toss it now? I have more stock chemistry to mix so it's not a problem to make a new liter. My main reason for asking is that I would like to know if this quickly rising contrast is a way to tell that it's time for a new batch of developer and blix. In reading the "Darkroom Cookbook", Steve Anchell writes about rising contrast as B/W paper developers move towards exhaustion due to bromide buildup and I am wondering if the same sort of thing is happening here?

  2. #2

    Join Date
    Nov 2009
    Location
    Capital of Oregon Territory
    Shooter
    Multi Format
    Posts
    764
    Have you considered replenishment? Check with your chemistry but I think you could dump and replenish about 10mL per 8x10 sheet. That way the chemistry will last quite a bit longer.

    Also, since you are doing tray development, do you keep track of the tray temperature? Could it be that it's just cooling down with time?

  3. #3
    kb3lms's Avatar
    Join Date
    Jun 2006
    Location
    Reading, PA USA
    Shooter
    35mm
    Posts
    696
    Images
    5
    WRT replenishment, would you mean, for example, making two liters instead of one and the topping up say 10mL of fresh chemistry for each 8x10. The maybe discard and start over when the second litre has been used up?

    This is room temp development, in my basement. Temp is a constant 70 deg F.

  4. #4

    Join Date
    Nov 2009
    Location
    Capital of Oregon Territory
    Shooter
    Multi Format
    Posts
    764
    Yes, something like that. I don't think you need to replenish after every sheet. I usually dump/replenish with about 100mL after half-dozen 8x10s or so. The chemistry in trays does oxidize more quickly than in a roller-transport machine (what I use), so you may need to replenish with higher amount.

  5. #5
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    22,972
    Images
    65
    You are at capacity or way over with that many prints in 1 L of Developer. Check the Kodak web site for capacity.

    PE

  6. #6

    Join Date
    Feb 2008
    Location
    Winnipeg, Canada
    Shooter
    Multi Format
    Posts
    1,301
    Here you go, http://www.kodak.com/global/en/profe...bs/j39/j39.pdf

    All you need to know about chemistry, and you have to consider deterioration when in a tray. See page 3 for the recommended capacity.

    Using it one shot in drums, I can get 3 8x10 per 70 ml by reusing the 70 ml for a couple 8x10 and 4 4x5 test prints, that is 6 trips thru the drum for the same 70 ml in a couple of hours. Which turns out to be 42 prints per liter.
    Bob

  7. #7
    kb3lms's Avatar
    Join Date
    Jun 2006
    Location
    Reading, PA USA
    Shooter
    35mm
    Posts
    696
    Images
    5
    Thank you, everyone. So, high contrast and colors not quite right, it's dead. Makes sense. Well, I cannot complain about the longevity of the chemistry. This batch worked long enough.

    Last night I went ahead and dumped the old solutions. The blix had a gray sludge that had settled in the bottom of the container and won't wash out. Any idea what that would be? The container is just a reused PET drink bottle so I will throw it away and start with a new one but just wondering if that sludge is pointing to any issue out of the ordinary.

  8. #8

    Join Date
    Nov 2009
    Location
    Capital of Oregon Territory
    Shooter
    Multi Format
    Posts
    764
    Quote Originally Posted by kb3lms View Post
    The blix had a gray sludge that had settled in the bottom of the container and won't wash out.
    Even heard of silver lining?

  9. #9
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    22,972
    Images
    65
    Sounds as if you really exhausted the blix too. The sludge is a mix of silver salts and iron salts. Some fresh blix might dissolve it given time. You might try a tray cleaner such as Dichromate + Sulfuric Acid.

    PE

  10. #10
    paul_c5x4's Avatar
    Join Date
    Apr 2009
    Location
    Ye Olde England
    Shooter
    Large Format
    Posts
    1,451
    Images
    23
    Quote Originally Posted by kb3lms View Post
    The blix had a gray sludge that had settled in the bottom of the container and won't wash out.
    Silver rich sludge that should not be disposed of in landfill or down the drain - Send it off for reprocessing or see if your local council has a toxic waste disposal facility.

    As for cleaning, I've used a thick toilet bleach to clean trays before now and have also tried Cilit Bang. Sodium Hydroxide is also good for removing (some) deposits.

Page 1 of 2 12 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin