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  1. #111
    Photo Engineer's Avatar
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    In either case, you are adding a burden to the environment. The sodium sulfite in a wash aid has to go somewhere, and peroxide in your effluent is not nice either.

    PE

  2. #112
    SchwinnParamount's Avatar
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    Quote Originally Posted by Photo Engineer View Post
    In either case, you are adding a burden to the environment. The sodium sulfite in a wash aid has to go somewhere, and peroxide in your effluent is not nice either.

    PE
    I don't want that stuff in the environment either but you're right... it has to go someplace.

    So I drink it.


    On another and probably un-related note, I've got this weird third ear growing out of the back of my head. I can hear 33% better of course, but people look at me funny.

  3. #113
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    good info, a product I don't really need. Thanks

  4. #114
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    Quote Originally Posted by CBG View Post
    Your conclusions about when to use wash aids are right on, but I have a problem with the term "wash aid" being characterized as synonymous with "hypo eliminator". They are not at all the same.

    I know it sounds rather nitpicky, but I hope the terminology of wash aids and hypo eliminators becomes better understood and used since all these terms can be so confusing to beginners under even the best circumstances.
    If you look back at my message you will find that Washaid was capitalized as a single word, that is usually an indication that it's being used as a product name, not a generic term. In this case you really need to take that up with Ilford. Considering that I first heard of that product 3 decades ago, it's been around a long time, they do refer to it as a hypo eliminator on their web site.

    I also don't know if hypo eliminators really make a huge difference with rapid fixers that do not contain any hypo, when using the short fixing times with modern films and RC papers.
    Paul Schmidt
    See my Blog at http://clickandspin.blogspot.com

    The greatest advance in photography in the last 100 years is not digital, it's odourless stop bath....

  5. #115
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    Quote Originally Posted by wogster View Post
    I also don't know if hypo eliminators really make a huge difference with rapid fixers that do not contain any hypo, when using the short fixing times with modern films and RC papers.
    I know of no fixer today that has another fixing agent in it that exclusively replaces Hypo. Can you explain a bit? Thanks.

    PE

  6. #116

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    P. K. Turner 1943

    Quote Originally Posted by CBG View Post
    Hypo eliminators are completely different; they
    destroy hypo within the paper rather than
    helping it be removed from the paper.
    "What hypo is not washed out is then turned to sodium
    sulfate, which is harmless." He is writing of potassium
    permanganate and the washing of film.

    After a first wash the film is further washed in water
    tinted with the permanganate. If the the tinted water
    goes colorless further washing is needed. Dan

  7. #117
    CBG
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    Wogster - Ilford's info on their "Washaid" branded washing aid simple adds to the confusion. They misuse the term hypo eliminator too. I think I'm fighting a losing battle.

  8. #118

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    Quote Originally Posted by CBG View Post

    Wash aids are rather gentle in effect, merely allowing better
    diffusion of water and chemicals in and out of the paper base.
    Wash aids are invariably alkaline, mildly to quite. As well
    as sodium sulfite alone or laced with the bisulfite there is
    sodium carbonate. The latter recommended by Agfa.

    I believe the mechanism involved is ion exchange.
    The hydroxyl ion population being high results in
    detachment of the silver bering thiosulfate
    ions. Non silver laden thiosulfate, I'd
    suppose ditto.

    Quite a few chemicals can serve well as hypo
    clearing agents. Sodium sulfite is the only
    one to be quantified, publicly. Dan

  9. #119
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    Quote Originally Posted by Photo Engineer View Post
    I know of no fixer today that has another fixing agent in it that exclusively replaces Hypo. Can you explain a bit? Thanks.

    PE
    I thought Hypo referred to hyposulphate of soda - AKA sodium thiosulphate, the fixer I currently use is based on ammonium thiosulphate, which isn't hypo.

    The real question then is, does a hypo eliminator do anything when you use an ammonium thiosulphate based fixer?
    Paul Schmidt
    See my Blog at http://clickandspin.blogspot.com

    The greatest advance in photography in the last 100 years is not digital, it's odourless stop bath....

  10. #120
    Photo Engineer's Avatar
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    Hypo refers only to the Thiosulfate end of the molecule Paul.

    HEs work on any thiosulfate, but since Ammonium Thiosulfate and its complexes with silver are more soluable and smaller, the effect is harder to see in some cases. But then, you have the HE to eliminate somehow!

    PE



 

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