silver precipitate in bottles

Discussion in 'Darkroom Developing and Printing' started by Tom Phillips, Nov 4, 2003.

  1. Tom Phillips

    Tom Phillips Guest

    Been a while since I read/posted to rec.darkroom but I
    see most of the regulars are still around so maybe
    someone can answer a question :) Cleaning out my darkroom
    recently I found several old bottles (brown plastic type)
    full of used fixer (both hardner and non.) After rinsing
    out what I assume was sulfur precipitate (white crystalline
    stuff) I noticed a good deal of silver precipitate in the
    bottoms.

    Question: how can I dissolve this out? Never had to do this
    before but vaguely remember a post several months back on
    this (e.g., a particular solution?) that might be effective
    but can't find it in my saved threads.

    Thanks for any info

    Tom Phillips
     
    Tom Phillips, Nov 4, 2003
    #1
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  2. Edwal tray cleaner (or similar product). This will dissolve the silver.
    You can also try just using a bottle brush, it usually doesn't stick
    very hard.
     
    Robert D Feinman, Nov 4, 2003
    #2
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  3. aha...used fixer container. Just use good old laundry bleach. Clorex (tm)
    will work just fine. Stand back from the fumes that can get created.
     
    Lawrence Akutagawa, Nov 4, 2003
    #3
  4. Probably potassium ferrocyanide would work.
     
    Michael Scarpitti, Nov 4, 2003
    #4
  5. Back when I ran an E-6 roller transport processor, the manufacturer
    (Colenta) recommended against cleaning fix tanks with Clorox. Apparently,
    any residual Clorox would combine with any residual fix and create a
    precipitate that was not water-soluble.
     
    Mark Wolenski, Nov 4, 2003
    #5
  6. The two traditional tray cleaners both contain concentrated
    Sulfuric acid and one contains Potassium bichromate, which
    is somewhat hazardous and is a carcinogen. It can cause
    severe burns so handle it with care. The mixed tray cleaner
    solution is not particular hazardous but should be kept off
    your hands.
    The caution for Sulfuric acid is that it must always be
    added to a volume of water, not the other way around.
    Sulfuric is very exothermic, i.e., generates a lot of heat
    when it goes into solution, If you add water to the acid it
    will boil instantly and splatter acid around.
    Kodak TC-1 was a pretty standard laboratory glass cleaner.
    It can be used many times.
    TC-2 is especially recommended for removing silver stains.

    Kodak TC-1 General Purpose Tray Cleaner

    Water 1.0 liter
    Potassium Bichromate 90.0 grams
    Sulfuric Acid, concentrated 96.0 ml

    Pour some of this solution into the tray or bottle and swirl
    it around until the stain is removed. Rinse well with water.


    Kodak TC-2 Silver Stain Remover
    Solution A
    Water 1.0 liter
    Potassium Permanganate 5.0 grams
    Sulfuric Acid, concentrated 10.0 ml

    Solution B
    Water 1.0 liter
    Sodium Bisulfite 10.0 grams

    For use pour Solution A into the tray or bottle and allow it
    to remain a few minutes, then rinse with water. Apply
    Solution B, and wash thoroughly.

    Before getting the ingredients for this try Clorox
    followed by a water rinse and _fresh_ rapid fixer.
     
    Richard Knoppow, Nov 5, 2003
    #6
  7. Good idea, but I think potassium ferricynade with some potassium
    bromide would be even better. If anybody has the formula for C-22
    bleach, this is what I'd try.

    Mike Sullivan
     
    Mike Sullivan, Nov 5, 2003
    #7
  8. Good idea, but I think potassium ferricynade with some potassium
    Or how about some used but not exhausted bleach or blix from any color
    process?
     
    Michael A. Covington, Nov 5, 2003
    #8
  9. Tom Phillips

    Tom Phillips Guest

    The tray cleaner sounds like a good bet. I might try a couple of the
    suggestions everyone provided. I usually find bottle brushes only partly
    effective: depending on the size and shape of the bottle it's hard to
    get out all the residue stuck to the bottom and sides.

    Thanks!
     
    Tom Phillips, Nov 5, 2003
    #9
  10. Tom Phillips

    Tom Phillips Guest


    Thanks Richard. TC-2 solution A is listed in some of my references as
    Permanganate Bleach. Solution B (the Sodium Bisulfite) seems essentially
    a biocide of sorts used to kill mold etc. so probably not needed in my
    case. I have the sulfuric but not the permanganate, but the
    Clorox-water-fix rinse you suggest actually seems to be working. Don't
    know why but it is.

    Tom
     
    Tom Phillips, Nov 5, 2003
    #10
  11. Tom Phillips

    Tom Phillips Guest

    I thought about that but had no mixed color chemistry. I tried both
    ferricyanide and Clorox in succession (rinse in between.) Not sure which
    worked (or both) but some dissolving took place. I let the clorox sit in
    the bottle for a while, shook it, then rinsed and used fresh rapid fix
    as Richard suggested (but undiluted.) Removed most of the silver deposit.
     
    Tom Phillips, Nov 5, 2003
    #11
  12. Tom Phillips

    friend Guest

    it's rather silver sulfide, not metallic silver. Use
    permanganate/sulfuric acid as per Mr Knoppow. Or better, get the new
    bottle. The cost of cleaning and disposing of this shit is far more
    than the cost of a new bottle.
     
    friend, Nov 5, 2003
    #12
  13. Tom Phillips

    Tom Phillips Guest

    Technically it's a compound, but references I have for Ag2S describe the
    majority of sulfides as "metallic." Sure looks metallic in the bottom of
    my bottle, hence my describing it as "metallic."
    But I'm emotionally attached to my bottles :)

    Kodak recommends Clorox followed by fresh fixer as Richard suggested.
    They have a PDF:

    http://wwwes.kodak.com/global/en/professional/support/techPubs/cis167/cis167.pdf
     
    Tom Phillips, Nov 6, 2003
    #13
  14. I've got a related follow-up question: I find lots of stuff deposited on the
    inside of the bottle I use for paper developer (Dektol). I've been just
    reusing the bottle after rinsing it, but pretty much gave up on trying to
    remove the crud. I figure it's precipitate, which is pretty much insoluble, so
    how much harm could it do?

    So, how much harm could it do?
     
    David Nebenzahl, Nov 6, 2003
    #14
  15. Tom Phillips

    friend Guest

    then accept them as they are [double smile]
     
    friend, Nov 6, 2003
    #15
  16. Tom Phillips

    Tom Phillips Guest

    I've never noticed this, that dektol or other deveopers precipitate
    anything and occasionally I've left unused stock dektol in a bottle for
    months. Dektol does tend to stain. Maybe that's what you see, unless
    you've been using the same bottle for chemicals other than developer
    (not a good idea) or it's your tap water.
     
    Tom Phillips, Nov 6, 2003
    #16
  17. It's a stain, then. The bottle has only been used for Dektol, and my water is
    relatively soft here. So do I need to worry about this or not? (Currently I
    don't.)
     
    David Nebenzahl, Nov 6, 2003
    #17
  18. Tom Phillips

    Tom Phillips Guest

    I never have, and have never heard of anyone considering it any sort of
    problem. Occasionally I scrub my developing tray, but that's all.
     
    Tom Phillips, Nov 6, 2003
    #18
  19. Tom Phillips

    friend©® Guest

    use acetone to get rid of organics, use water to remove soluble
    inorganics, use bleach to remove stubborn stains. Wash well with
    plenty of water. Dedicate bottles to each process, never "cross".
    Unless you developed (no pun) bottle fetish - replace them frequently.
     
    friend©®, Nov 6, 2003
    #19
  20. Tom Phillips

    Jorge Omar Guest

    Is that what one is supposed to do from 20 to 20 yrs?
    (-:

    Jorge
     
    Jorge Omar, Nov 6, 2003
    #20
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