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  1. #21

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    Quote Originally Posted by Gerald C Koch View Post
    Has anyone thought to test the film for residual silver? If not then the results are meaningless. An improperly fixed negative will eventually fade.
    Yes, fair comment.
    Attachment shows the fog levels with proprietary fixer, table salt fixer, and a strip fixed in table salt then redeveloped for 3x recommended time and washed only.
    The darker color of the redeveloped strip suggests that the table salt strip was not quite completely fixed. Perhaps after years it would darken to the density of the redeveloped strip.
    Attached Thumbnails Attached Thumbnails fog levels.jpg  

  2. #22

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    It would be interesting to check the fixation with other films such as a fast film and a film which has a high iodide content such as T-grain or Delta films. These films are slow to fix with thiosulfate and should prove a challenge to a salt fixer.
    Last edited by Gerald C Koch; 10-06-2013 at 03:13 PM. Click to view previous post history.
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  3. #23

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    I am more impressed that the emulsion was still on the base after 24 hours at 27 degrees and intermittent agitation.
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  4. #24
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    Quote Originally Posted by A-Shooter View Post
    The anti-caking agent in the table salt may give some fixing action depending on what agent is used. Some table salts contains small amounts of potassium or sodium thiocyanate. This is an express fixer agent. The amount in 150g salt used alone may fix he film in 10-15 minutes, but the salt really hampers the action.
    If you look at these tables, you will see that Silver Chloride is quite soluble in Sodium Chloride, but that Ammonium Chloride works even better. Silver Bromide and Silver Iodide, of course, won't be easy to fix that way, but fortunately most common table salt contains Iodide which works as stabilizer. Likewise, the Thiocyanate you mentioned as anti caking agent will rather work as stabilizer, not as fixer.

    If you have to fix film and just can't possibly get your hands on any trace of Thiosulfate, I would recommend multiple bathes of concentrated Ammonium Chloride at elevated temperature, with each fixing step no longer than 10 minutes. There is no need to wash between fixing steps in such a setup.
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  5. #25

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    hi rudeofus

    i have often thought of using salt if i can't get my hands on fix ...
    once the film ( or print ? ) is soaked in salt and washed ...
    when it is fixed in traditional fixer are there any worries of the image
    film or paper being damaged by the fixer?

    thanks!
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  6. #26

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    The amount of iodide in table salt is far too small to be of any use in fixing emulsions that contain silver iodide such as T-grain films.

    Since a salt solution takes so very long to fix film it really is not a practical substitute for conventional fixers.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  7. #27
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    Quote Originally Posted by jnanian View Post
    i have often thought of using salt if i can't get my hands on fix ...
    once the film ( or print ? ) is soaked in salt and washed ...
    when it is fixed in traditional fixer are there any worries of the image
    film or paper being damaged by the fixer?
    I don't think that table salt can damage your film, but please consider that Silver Iodide is VERY insoluble (by seven orders of magnitude less than Silver Chloride!), therefore I don't think you can properly fix a modern Silver Bromide Iodide emulsion with rock salt. Note, that the tables I linked to are for Silver Chloride, not the other Halides. You should be able to fix warm tone paper with rock salt, though.

    Since inability to obtain Thiosulfate based fixer can only be a temporary issue in most parts of the world, you may want to look at stabilizer recipes which should keep your film stable until you get proper fixer. There are several recipes for stabilizer in Haist's book and probably elsewhere. Since stabilizers are quite dilute compared to fixer, keeping an emergency stash of their ingredients should require very little space and monetary effort.
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  8. #28
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    Quote Originally Posted by jnanian View Post
    ... in order to get the color tinge out of the film.
    (tmy, tmx and tmz at least )
    I'm not sure what the big deal was here. I always use regular hypo and I don't see what the side effects could possibly be. The only valid issue I have seen would be with some pyros.
    Get it right in the camera, the first time...

  9. #29
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    Quote Originally Posted by mrred View Post
    I'm not sure what the big deal was here. I always use regular hypo and I don't see what the side effects could possibly be.
    The main "side effect" is that Sodium Thiosulfate takes over three times as long as Ammonium Thiosulfate to fix film at the same molar concentration. Since T-grain films seem to be notoriously hard to fix properly (as indicated by the magenta cast that weak or used fixer leaves on the film), people tend to use the best fixers possible for these films.
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  10. #30
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    I'm not entirely sure the cast is unfixed silver. A couple years ago I put some "coloured tmy" in the window for a few months with no change. The reason I did this test was that I was told the cast would go away with exposure to uv. I guess both are a myth.

    I have read here that a bath of sodium sulfate would clear it up. (http://www.apug.org/forums/forum37/1...not-clear.html) post #6

    I will concede the time. I rotory process and tend to go long anyway. Salt would be too long for me, but is an alternative.
    Get it right in the camera, the first time...

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