Hardening Fixer Needed

Discussion in 'B&W: Film, Paper, Chemistry' started by dpneal, May 31, 2004.

  1. dpneal

    dpneal Member

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    Thanks to the great advice from the APUG.org community, I've been developing film at home -- Diafine, Water Stop, and TF-4. The trouble is that it has become quite obvious that I need a hardening fixer; I shoot Arista.EDU 100 and I've noticed lots of damage to the emulsion even after my most gentle handling.

    So, can anyone suggest a fixer that 1) doesn't require the use of a hypoclear agent; 2) is relatively odor-free; and 3) incorporates a hardener?

    Thanks!

    Dan
     
  2. ann

    ann Subscriber

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    Kodak makes a fixer that has a hardner already in the concentrate i think it is called Kodakfix. They also make a fixer that has two parts, one the hardner the other fixer and one can mix as desired. It is my understanding that any fixer with a hardner will need a hca for decreasing the wash times; which may not be an issue for you.
    I am sure someone with more knowledge will chime in about this issue a bit later.
     
  3. Tom Hoskinson

    Tom Hoskinson Member

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    Dan,
    Arista.EDU 100 is made in Hungary by Forte. The Forte emulsion is soft and is easily damaged. However, I routinely process Forte sheet and roll films without experiencing emulsion damage. I do not use a hardening fixer.

    If you are tube processing EDU sheet film, the emulsion can easily be damaged during insertion and/or removal of the film from the tube.

    If you are tray processing, emulsion damage can happen during development and any of the subsequent steps. In either case, adding hardener to the fixer is probably not going to solve the problem. The best corrective action is to improve your film handling techniques. You may need to sacrifice some film by processing with the lights on, in order to determine what is going wrong.

    If you are processing Arista.EDU 100 roll film on reels, you should not be having this problem.
     
  4. Tom Hoskinson

    Tom Hoskinson Member

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    Dan,
    With regard to Hypo Clearing Agents (HCA) I quote this 1997 posting by Richard Knoppow, followed by a comment of my own.

    "Kodak Hypo Clearing Agent and other so called washing aids are the
    result of the discovery that sea water was more effective for washing out
    hypo than fresh water. This was first noted around the turn of the century
    but extensive research was not until WW-II when the problem of washing
    photographic materials on ship board or other locations where fresh water
    was in short supply became critical.
    It would appear that wash aids work mostly by an ion exchange mechanism.
    I've never seen a clear explanation of this so can’t provide a citation.
    Kodak Wash Aid is approximately: Sodium Sulfite, dessicated, 100 gm; Sodium
    Bisulfite, 10 gm; Water 1.0 liter. Dilute 1 part stock to 4 parts water
    for use. The commercial product will contain the usual chelating agents in
    it to deal with hard water.
    Kodak HE-1 Hypo Eliminator is works on a different principle. It
    converts the residual hypo to Sodium Sulfate which is more soluble. Kodak
    has recommended against using hypo eliminator for several years. It can
    damage emulsion and may be too effective washing out the hypo. It was
    discovered around 1960 that very small residues of hypo actually stabilize
    the silver!
    I am not sure what advantage Ammonium salt would have over Sodium but
    Crabtree et al of Kodak mentions the use of Ammonium Carbonate as a washing
    accelerator in an early paper. It was thought at that time that the main
    function of the salt was in changing the pH of the gelatin rather than the
    more complex one of ion exchange.
    ----
    Richard Knoppow
    Los Angeles, Ca
    dickburk@ix.netcom.com


    http://www.usask.ca/lists/alt-photo-process/1997/alt97b/1218.html

    In summary: For fixers that already contain sodium sulfite (and many do), an additional HCA is redundant. If your fixer does not contain sodium sulfite, add about 15 grams per liter (2 teaspoons) to the working strength fixer bath and forget a separate HCA. Tom Hoskinson, 5/31/04
     
  5. Ole

    Ole Moderator Staff Member Moderator

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    Developer Hardener?

    Maybe what you need is a hardening developer?

    There are basically two options: Most staining developers have a hardening effect. The other option is LP-GELADUR from LaborPartner. The English version of the website seems to be missing at present. I have never tried it, but there are rumors that it works...
     
  6. skahde

    skahde Member

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    Don't forget that HCA is alkaline whereas a fixer may be acid or alkaline independently from the sulfite and alkaline conditons promote thiocyanate removal. This may be the reasons why alkaline fixers formulated with sulfite do not need HCA. Acid fixers contaning enough sulfite will probably need at least an alkaline afterbath to wash out residual fixer with comparable efficiency. To me it appears to be safer to include HCA as long as you don't know all these variables for sure.

    Stefan
     
  7. Tom Hoskinson

    Tom Hoskinson Member

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    You need water to remove the residual hypo. The hypo removal process from the emulsion is primarily a chemical diffusion process. This is true for both acid and alkaline fixer baths - with and without HCA.

    Hardening the emulsion during or prior to development won't help if the film is scratched in handling before development. I should note that I develop with Pyrocat-HD which tans and hardens the emulsion.

    Film can be damaged by surface water removal (wiping the film before drying). If this is the case, emulsion hardening may help. An alternative is to use photo-flo (or equivalent) in distilled water for the final rinse and eliminate the wiping.
     
  8. skahde

    skahde Member

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    Tom,

    i should have read the thread before stepping on my soapbox: I thought we were talking about paper where things are bit different.

    Stefan
     
  9. Tom Hoskinson

    Tom Hoskinson Member

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    No worries, Stefan.
     
  10. garryl

    garryl Member

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    May I point out two things in the original post-

    >I shoot Arista.EDU 100 and I've noticed lots of damage to the emulsion even after my most gentle handling.<

    >plus it say under" shooter;" Medium Format.
     
  11. Tom Hoskinson

    Tom Hoskinson Member

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    Yep, saw that, and posted:

    "If you are processing Arista.EDU 100 roll film on reels, you should not be having this problem."

    And: "Film can be damaged by surface water removal (wiping the film before drying). If this is the case, emulsion hardening may help. An alternative is to use photo-flo (or equivalent) in distilled water for the final rinse and eliminate the wiping."
     
  12. dpneal

    dpneal Member

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    Thanks for the feedback everyone.

    1. Yeah, I'm processing the film on reels. As far as I can tell, the damage isn't occuring during the processing, but instead when I look at my negatives (emulsion side down) on my light box. Viewing my unsleeved negs on my light box is part of my normal routine, and I have never noticed damage to them before (when the negs were fixed by a conventional fixer). Oh, and the damaged negatives were totally dry when I examined them on my light box -- they had been hanging in my bathroom for around twelve hours.

    2. I use photo-flo and distilled water for my final rinse. I don't wipe the film before drying at all. No water spots so far, knock on wood.

    For the sake of convenience and a non-chemically-stinky bathroom, I think that I'm just going to continue with the TF-4 and just avoid handling my negatives AT ALL when they're unsleeved. I just hope that they don't get scratches when I'm pulling them into and out of sleeves and negative carriers when I'm printing! I also might try a more modern film that incorporates its own hardening agent, but it's hard to beat $1.29/roll for the Arista. :smile: