Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,200   Posts: 1,531,515   Online: 1015
      
Results 1 to 5 of 5
  1. #1

    Join Date
    Sep 2008
    Shooter
    35mm
    Posts
    21

    ferric oxalate questions

    I understand Ferric Oxalate deteriorates over time.

    What is the expected shelf life?

    If I use "stale" ferric oxalate, how will the image look?

    Can it be extended by refrigeration if a few days/weeks inactivity is expected?

    Finally, what is the impact of the addition of potassium chlorate as a "restrainer" in the B&S 2 solution? Does it make the resulting positive image more contrasty or less?

    Thanks.

  2. #2
    Peter Spangenberg's Avatar
    Join Date
    Dec 2005
    Location
    Chagrin Falls, Ohio
    Shooter
    Large Format
    Posts
    125
    Images
    42
    I was concerned about this and spoke with the guys at B&S a couple of months ago and they advised that THEIR ferric oxalate has a pretty long shelf life (their process is apparently proprietary/patented). I was told to expect in excess of 1 year. I have been using some that I have had for 6-8 months and it's still fine. Evidently the images start to look muddy with reduced contrast. I have yet to experience it with their product.

  3. #3
    Vaughn's Avatar
    Join Date
    Dec 2006
    Location
    Humboldt Co.
    Shooter
    8x10 Format
    Posts
    4,629
    Images
    40
    I tend to buy a couple of bottle at a time and stash one in the fridge. I try not to have one opened for more than a few months (up to six), and I don't worry about the age of the refridgerated one. But if I am not sure about the age and/or condition, I don't use it. The stuff is too cheap to take a chance of wasting platinum and palladium salts. I tend to coat 6 to 10 8x10 sheets at one time and then print until I use them all, so it is not worth my time to coat just one sheet for a test (I have to travel up to where I print...10 miles away...pull out and set up trays, chemicals, equipment, etc).

    Vaughn
    At least with LF landscape, a bad day of photography can still be a good day of exercise.

  4. #4

    Join Date
    Oct 2005
    Location
    Pakistan
    Shooter
    Multi Format
    Posts
    266
    If I remember correctly, the print tends to get more contrasty with older FO. However, an easy way to rejuvenate an FO solution is to add a few drops of hydrogen peroxide. This reliably changes the ferrous oxalate back to ferric. I do this routinely when I pick up an older bottle I haven't used for some months.

  5. #5

    Join Date
    Aug 2005
    Location
    Los Alamos, NM
    Shooter
    Multi Format
    Posts
    2,044
    One thing to remember is that ferric oxalate is light sensitive. Keep it in the dark, as well as cool and (if powder) dry.



 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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