Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 69,963   Posts: 1,523,182   Online: 839
      
Results 1 to 7 of 7
  1. #1

    Join Date
    May 2006
    Location
    Jonesboro, GA
    Shooter
    Multi Format
    Posts
    362

    D-76 stock solution storage life

    I have just inadvertently tested the storage life of D-76 stock solution. I normally make up 1 gallon of undiluted solution using distilled water, put it up in 1 liter heavy plastic bottles with as much air as possible squeezed off. These I then dilute 1 to 1 as needed.

    Yesterday it seemed time to mix up a fresh gallon. Searching around in my storage cupboard I found to my chagrin a liter bottle, unused, labelled 3/24/2010. It had been kept a room temperature, and in the dark.

    Since I had a cassette of film used just for fooling around I processed it, the results look good. Kodak, with commendable caution, cites a 6 month storage life. While I can't recommend over two years, at least it does seem to work properly.

  2. #2
    cliveh's Avatar
    Join Date
    Oct 2010
    Shooter
    35mm RF
    Posts
    3,127
    Images
    340
    I quite often use D76 which is over a year old and kept on a window ledge. As long as you don't let it oxidise it will probably keep for 2 years or more.

    “The contemplation of things as they are, without error or confusion, without substitution or imposture, is in itself a nobler thing than a whole harvest of invention”

    Francis Bacon

  3. #3
    pstake's Avatar
    Join Date
    May 2005
    Shooter
    Multi Format
    Posts
    704
    Images
    64
    Good to know!

  4. #4

    Join Date
    Jan 2007
    Shooter
    Medium Format
    Posts
    828
    Images
    131
    Two years easy, as long as you don't mix the powder and water in a blender.

  5. #5

    Join Date
    Feb 2010
    Location
    Montreal, Canada
    Shooter
    Multi Format
    Posts
    4,539
    ...however it is well known the pH of D76 rises over time with storage, making it more active. This would tend to raise contrast.

  6. #6
    brian steinberger's Avatar
    Join Date
    Jan 2007
    Location
    Pennsylvania
    Shooter
    Med. Format RF
    Posts
    2,328
    Blog Entries
    1
    Images
    100
    Quote Originally Posted by Michael R 1974 View Post
    ...however it is well known the pH of D76 rises over time with storage, making it more active. This would tend to raise contrast.
    I was always curious, over how much time are we talking? I mix up 5L of ID-11 and use it all within 3 months.

  7. #7

    Join Date
    Feb 2010
    Location
    Montreal, Canada
    Shooter
    Multi Format
    Posts
    4,539
    Brian, my understanding is that if the "original" formula is used the pH can increase over the first few months - ie it is not limited to long term storage. However I probably should have been clearer in my post that if you buy packaged D76 or ID11 this may not necessarily be the case. Who knows what tinkering has been done by Kodak over 80 years. And Ilford's two-part packaging may indicate it is slightly different in composition to packaged D76 as well.

    Some people say the pH still rises, some say the pH rises but the effect of higher activity is largely offset by the loss of Hydroquinone in that reaction, and I've even seen it said the current versions of these developers do not undergo a significant pH change with storage.

    So apologies in retrospect for being too simplistic in the post. It would be interesting to test this with both D76 and ID11, but I wonder how reliable the results would be unless done by the manufacturers. Simple experimental error, different storage conditions and/or normal processing variations could make it difficult to come to conclusions outside a laboratory setting unless the results repeatedly showed big differences over time. If not, I guess we don't have anything too significant to worry about.



 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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