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  1. #11
    Worker 11811's Avatar
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    I know this isn't the formula the OP was looking for. However, I think this might be a good time to share something.

    I have a 36-page booklet entitled, "Agfa Formulas for Photographic Use."
    It contains a whole bunch of formulas for developers, fixers, hardeners and all sorts of other stuff.

    Here is an excerpt from that booklet:
    AGFA 203
    NON-HARDENING METABISULPHITE FIXER
    This fixing bath is recommended for use when hardening is not desired. It is highly desirable for accuracy of registration in color work with Reprolith Film.
    Stock Solution
    Hypo ... 1900 grams (4 lb.)
    Agfa Potassium Metabisulphite ... 270 grams (9 oz.)
    Water to make ... 4 liters (1 gal.)

    The Metabisulphite should be added only when the Hypo solution is cool.
    For use, dilute one part stock solution with one part water. Normal fixing time 5 to 10 minutes at 68º F. (20º C.).


    This booklet was published in 1941 and it contains no formal declaration of copyright. (e.g. "Copyright © 19xx - John Smith - All rights reserved.) So, according to what I understand, this publication is in public domain for two reasons: The copyright is expired, plus there is no formal declaration of copyright.

    Therefore, if anybody is interested in reading this booklet, send me an e-mail or a P.M. and I'll reply with a link where you can download a PDF copy of the book.

    One word of warning: This booklet contains formulas for things that are toxic and very dangerous such as Monckhoven's Intensifier and other formulas that contain substances like mercuric chloride and potassium cyanide. This is the main reason why I'm not publishing the link in the clear. While there are many useful formulas in the booklet and it makes interesting reading on an academic level, I want everybody to understand that they follow the directions contained therein at their own risk.

    Again, if you're interested to read this book, send me a message...
    Randy S.

    In girum imus nocte et consumimur igni.

    -----

    http://www.flickr.com/photos/randystankey/

  2. #12

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    Quote Originally Posted by Rudeofus View Post
    Is there one credible reason why we should use potassium metabisulfite instead of sodium metabisulfite? To my best knowledge potassium ions do not exactly help fixer activity either, quite to the contrary. Also, the amount of thiosulfate is almost doubled for no apparent reason. I have seen that recipe posted over and over again but really doubt anyone would mix it like this.
    None that I can tell. I just copied the formula from refernce material.

  3. #13
    Ian Grant's Avatar
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    Kodak and Agfa both used Potassium Metabisulphite in commercial fixers and all companies used Potassium Alum in their hardeners. It seems to be high levels of Potassium ions that's important not so much their presence at relatively low levels. So you don't use Potassium Thiosulphate as the fixing agent.

    Ian

  4. #14
    Rudeofus's Avatar
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    Ian: if you look at recipes calling for metabisulfite, 99% of them use the sodium version (which is the most easy to get version anyway), except for this one recipe which I happen to see posted all over the place. Since potassium doesn't improve the action of thiosulfate, I didn't understand the motivation for using potassium metabisulfite. As it turns out, the poster doesn't know the reasons for K2S2O5 either, he just copied the recipe off somewhere for our convenience.

    willbill: Ammonium thiosulfate makes great fixers and it has become very popular once it became affordable. Unluckily, we live in a time now where the economy of scale does no longer work for ammonium thiosulfate, at least not in home brew quantities. If you bought it by the metric ton, it would be still cheap, so you will find rapid fixer cheaper than if you buy the raw chems. One of my home brew projects (on back burner right now) is mixing, testing and optimizing sodium thiosulfate based fixers, and Ole's quick fix will be my starting point.
    Trying to be the best of whatever I am, even if what I am is no good.

  5. #15
    Ian Grant's Avatar
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    Rudeofus, I've a very large collection of published formulae of all types and Potassium Metabisulphite was used with Ammonium Thiosulphate in some commercial formulae, I don't bother collecting home made recipes.

    Sometimes there's exaggerated claims made that fixers should be Potassium free after all it's still used in some commercial fixers.

    I'd clarify that the formula posted by Worker 11811 is not actually an Agfa formula rather it's the Agfa Ansco/GAF 203 Fixer, unfortunately numbers and formulae don't match between the two companies.

    Ian

  6. #16
    Ian Grant's Avatar
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    I'd add that one commercial fixer contains Ammonium Thiosulphate, Potassium Sulphite and Potassium Metabisulphite and taht's from one of the top 4 manufacturers (Kodak, Agfa, Ilford & Fuji).

    Ian

  7. #17
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    yeah, I'm looking for something that does the job for both film/paper, doesn't stink, and lasts a long time in concentrated form. The Arista Oderless does that. I've searched this stuff over and over the last couple years and now I actually need to get it done. You guys are too smart for me.
    www.vinnywalsh.com

    I know what I want but I just don't know how to go about gettin' it.-Hendrix

  8. #18

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    Hello,
    the most popular AGFA fixer formula was AGFA 300. In some sources you read potassiummetabisulfite (K2S2O5), in others sodium metabisulfite in the same concentration and some cases "Natriumbisulfit Lauge" which is a aqueous solution of sodiumhydrogensulfite (is widely used in the paper and cellulose industry). These substances are interchangeable. Sodiummetabisulfite as well as potassiummetabisulfite are commercially available as a preservative for food and wine. Potassiumsulfite is available as a liquid solution sometimes under the trade name Thiosol (I think it is 45 %) e.g. from BASF and together with potassiumhydroxide is an essential ingredient of Rodinal. Ammoniumthiosulfate is mostly used as a liquid solution (58 - 60 %) as it easier to handle. Solid Ammoniumthiosulfate is more expensive and very hygroscopic and gets hard like a stone when it attracts moisture.

  9. #19
    Ian Grant's Avatar
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    Jochen, my two post WWII German Agfa books of formulae show Agfa 300 as having Potassium Metabisulphite

    Agfa 304 is a rapid fixer based on Sodium Thiosulphate and Ammonium Chloride (which forms ammonium Thiosulphate) and this also contains Potassium Metabisulphite.

    So substituting Ammonium Thiosulpate for the Sodium Thiosulpate and Ammonium Chloride and adding Potassium or Sodium Metabisulphte would give a fixer close to the MSDS the OP has shown.

    Incidentally all Kodaks fixers in one official Kodak Research Formulary contain Potassium salts, thats F5, F16, F52, F53, F54 and F54a these are all bublished in other Kodak publications.

    Ian

  10. #20
    Rudeofus's Avatar
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    Can we agree that some recipes which included potassium were posted some decades ago but that who ever created them may have had special reasons which may or may not apply to us? Some potassium salts are vastly better soluble than their sodium counter parts which would certainly help in creating a concentrate, so a fixer with potassium may be the more viable commercial product despite its (slightly) poorer fixing.

    The big "problem" is that commercially available rapid fixer is so cheap and good that barely anyone mixes his own stuff, which leads to endless repetition of untested (by the poster) recipes all over the place.
    Trying to be the best of whatever I am, even if what I am is no good.

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