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  1. #1
    Ian Grant's Avatar
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    Modern Rodinal Substitutes

    The formula for Rodinal R09 has never been officially published by Agfa. In the "Agfa" Book of Photographic Formulae, published by the Berlin Aniline Company in 1910, the company tells us:

    As "AgfA"-Rodinal contains only traces of carbonic alkalies, the use of distilled water for dilution is not necessary. In connection with the use of "Agfa"-Rodinal the following remarks should be carefully noted:

    In addition to neutral sulphite and water "Agfa"-Rodinal contains only an alkaline salt of Paramidophenol, but no excess of caustic alkali.

    PDF Rodinal 1910

    However it's possible to make formulae that's close to the current versions.

    Original Rodinal contained p-Aminophenol (once called Paramidophenol by Agfa) and this was formed by precipitation of the free base from p-Aminophenol hydrochloride using sulphite and carbonate (hence Agfa's comment "contains only traces of carbonic alkalies".


    The formula for Rodinal has changed and evolved presumably as high grade p-Aminophenol free base became commercially available, allowing Rodinal to be completely free of carbonates.

    J. Desalme published a " Concentrated Paraminophenol Developer of the Rodinal Type" in 1913, this was later included in L.P. Clerc's book "Photographic Theory and Practice".

    Sodium Carbonate & Sodium Sulphite are added to a solution of p-Aminophenol Hydrochloride which precipitates the free base, which is filtered and collected.

    The paste of p-Aminophenol free base is then added to a solution of Sodium Metabisulphite and Sodium Hydroxide added until all the free base is dissolved, finally a small amount of Metabisulphite is added until the first crystals of p-Aminophenol free base begin to form again.

    This mirrors Agfa's own description of early Rodinal, and accounts for the traces of carbonates, and the "no excess of caustic alkali". (J. Desalme was a photographic chemist specialising in aminophenols and other developing agents particularly for colour processing).

    Now we reach a point of contention "Free base" or "Hydrochloride", genuine Rodinal has always been made using the Free base of p-Aminophenol . (50g of p-Aminophenol is equivalent to 66.2 g p-Aminol hydrochloride). There is no evidence to suggest that Rodinal of any form has ever contained p-Aminophenol Hydrochloride.

    The MSDS sheets for both Rodinal and Calbe R09 show clearly that both developers contain p-Aminophenol free base (CAS 123-30-8) and not p-Aminophenol hydrochloride (CAS 51-78-5).

    Making a Rodinal substitute with p-Aminophenol Hydrochoride will leave free chlorides in the solution, and neutralise more Hydroxide, the amount of developing agent would need to be increased along by a factor of 1.33 and also more KOH added.

    Data on early Rodinal is hard to find but in a thread on Photo.Net "Edward Zimmermann" wrote:

    The formulas for Rodinal, resp. R09 (1964 to present), have never been published. The patent is for Paramidophenol developers and there are many recipes making the rounds since the late 1800s. One of the most famous is attributed to Eder. From my copy of Spörl and Neumann, "Fotografisches Rezeptbuch" 1943 edition, p.50):

    N16:

    • Paramidophenol 50g
    • Kaliummetabisulfit [Potasium Metabisulfite] 150g
    • Wasser 625ccm (ml)

    Then a solution of

    • Ätznatron [Sodium Hydroxide] 215g
    • Water 500ccm (ml)

    is slowly added untill the cloudyness breaks. According to the book it says this is typically around 350ml.
    Then the solution is diluted with water to make 1 liter.

    My note: 350ml of the Sodium Hydroxide solution contains 150.5 gms Sodium Hydroxide.

    The same formula was published in the British Journal Photographic Almanac (1910 & earlier) as:

    Paramidophenol.
    ONE-SOLUTION

    Potassium metabisulphite 300g
    Distilled water 1 litre
    Paramidophenol 100g

    Dissolve in the above order and add gradually:
    Caustic soda or potash to dissolve the precipitate first formed.

    For use, dilute 1 part. with 10-20 parts of water.

    No final volume of solution is given but it's likely to be 2 litres if you want the equivalent of early Rodinal.

    It's important to note that these sources clearly indicate the use of the free base, as they go on to also include p-Aminophenol Hydrochloride film developers. These are in the 1910 "Agfa" Book of Photographic Formulas, the 1910 BJP Almanac and Ed Zimmermann's book all from quite different sources & countries.

    However other versions of this formula appear in various books from the early 1900's onwards, but using p-Aminophenol Hydrochloride, because of the difference in Molecular Weight and the effects of the additional Hydrochloride they won't be quite the same. Dr M. Andresen, of Agfa, who discovered & patented p-Amaninopheol and designed Rodinal published it himself in the "AGFA Photo-Handbook" he did not claim it was similar to Rodinal, listing it as - Formula 21: Concentrated single solution. (As above proportions but using p-Aminophenol Hydrochloride).

    L.P.Clerc and others indicate that Potassium Metabisulphite was the preferred source for the Sulphite in Rodinal, Potassium salts are used in preference to Sodium because of their greater solubility in water which becomes far more important in concentrated developer solutions. Metabisulphite and Hydroxide form Sulphite in solution.

    At some point before or during WWII Agfa began using Potassium Sulphite and also adding Potassium Bromide and an anti-foggant to Rodinal. It's entirely possible that Agfa modified Rodinal so that it was more suitable for roll & particularly 35mm films which became cfommon in the 1930's.

    Some have made the assumption that this formula might be "Classic Rodinal" but if we compare it to a modern MSDS's it's only close s to Calbe's R09 MSDS for the p-Aminophnol.

    P-Aminophenol 50g - 5%
    Potassium Metabisulphite 150g - 15%
    Sodium Hydroxide - very approx 150g - 15%
    Water to 1 litre

    Calbe R09 MSDS

    P-Amininophenol 5%
    Potassium Sulphite 30%
    Potassium Hydroxide 4%

    However Potassium Metabisulphite is quite acidic in solution and will neutralize a considerable proportion of the Hydroxide. Replacing it with Potassium Sulphite cut's the amount of Hydroxide needed very substantially. Potassium Metabisulphite 5% solution has a pH of 3.8 - 4.6, while a similar Potassium Sulphite solution has a pH of 9 - 10

    Only one parameter seems to stay constant from early published alternatives through to Orwo/Calbe R09 - the fact that Rodinal is a 5% solution of p-Aminophenol free base in a sulphite solution, with no excess of alkali. It's reported that the Calbe product usually has a few crystals of the free base in the bottom of the bottle, which indicates no excess of Hydroxide.

    The British RAF report into the "Agfa Film Factory - Wolfen" reported by G.C. Brock, London : H.M.S.O. gives a formula for Rodinal as:

    Dissolve 34 kg of para-aminophenol in 340 litres of water. Add 558 kg of a 30% solution of potassium sulphite at 55C followed by 50 kg of a 34% potassium hydroxide solution, then 5.52 kg of potassium bromide in a little water. Add 42 g P.1347 (an Agfa-specific anti-foggant). Filter and allow to stand for 14 days.

    Knowing the Specific Gravities etc this seems to be around:

    p-Aminophenol 34kg
    Potassium Sulphite 128.08kg
    Potassium Hydroxide 12.57 kg
    Potassium Bromide 3.75 kg

    We aren't given a final volume, but if we relate this to the 5% p-Aminophenol of the Calbe MSDS this works out as:

    p-Aminophenol 5%
    Potassium Sulphite 19%
    Potassium Hydroxide 1.85%
    Potassium Bromide 0.77%

    But the Calbe/Orwo version of R09 is the pre-WWII formula and it's MSDS is

    p-Aminophenol 5%
    Potassium Sulphite 30%
    Potassium Hydroxide 4%
    Potassium Bromide - not included (below 1%)

    Unfortunately we can't really completely trust the RAF report, none of the Allied F.I.A.T. reports about Agfa products is entirely accurate, after all some Agfa employees were former members of the National Socialist Party (Nazi's). There is insufficient Potassium Hydroxide to react with the p-Aminophenol free base, and it is possible the resulting solution was then adjusted until the free base had just fully dissolved.

    Patrick "Gadget" Gainer has published "EZ Rodinal" which in terms of its ratio of p-Aminophenol to Potassium Hydroxide is probably close to Calbe R09 as there will be no excess of Hydroxide, the weights in brackets have been scaled to give a concentration of 5% p-Aminophenol.

    EZ Rodinal

    To 400 ml water, add:
    Sodium sulfite (anhyd) 85 g (106.3)
    p-Aminophenol base 40 g (50 g)
    Stir well. Add
    Sodium hydroxide 13.8 g or Potassium hydroxide 19.2 g (24g)
    Add water to make 500 ml. (1 litre)

    If EZ Rodinal; is adjusted a little further by adding 300 g of Potassium Sulphite in place of the Sodium Sulphite, some Potassium Bromide added plus some Benzotriazole and Potassium Hydroxide added slowly until the free base just dissolves

    EZ Rodinal New (Calbe R09 substitute)

    To 800 ml water, add:
    p-Aminophenol base 50 g
    Potassium sulphite (anhyd) 300 g
    Potassium hydroxide 24 g
    Potassium Bromide 0.8 g
    Benzotriazole 1% 10 ml
    Water to make 1 litre)

    This would be a lot close to the pre War formula and Calbe RO9, although this is itself now being made in a more concentrated form so that the dilutions & dev times are more comparable to Agfa /A&O Rodinal (post 1964)

    Patrick's second Rodinal substitute formulae is close to the Bayer/Agfa/A&O MSDS data-sheets for modern Rodinal:

    p-Aminophenol 4.1% (A&O)
    Potassium Sulphite 30-40%
    Potassium Hydroxide 2.7% (A&0)
    Potassium Bromide 1-5%
    Anti-foggant - not specified
    pH 14

    Gainer Rodinal Substitute

    To about 750 ml of water at room temperature, add
    p-Aminophenol 38 g
    Sodium sulfite (anh) 160 grams
    Sodium hydroxide 23 grams
    Water to 1 liter.

    This is on the right track, you need to use the free base and an excess of Hydroxide unlike the older R09 formula which has nearly 20% more p-Aminophenol and also requires using at a higher concentration to get equivalent results.

    In a post about Patrick's version a comment was made about the pH at 1:50 being roughly 11.6, Agfa Rodinal has a stock concentrate pH of 14 and a dilute pH of 11.55 so if this is the case Patrick's formula is about right, except too little Sulphite and there's no Bromide or anti-foggant.

    Agfa's modern Rodinal 1964 onwards uses an excess of Hydroxide and as a consequence is more active despite the lower level of p-Aminophenol than the previous formulae. Calbe R09 concentrate has a pH of 11.8.

    This is what I would use as a starting point for a good modern substitute:

    Rodinal Substitute

    p-Aminophenol.(free base) ................... 41 g
    Potassium sulphite (anh) ..................... 348 g
    Potassium Hydroxide ........................... 27 g
    Potassium Bromide ............................. 10 g
    Benzotriazole 1% ............................... 10 ml
    EDTA Na4 (optional) ........................... 6 g
    Water to make .................................. 1 litre.

    If necessary adjust to pH 14

    Some notes:
    The balance of the Bromide & Benzotriazole may need adjusting upwards..
    The mixed developer should be left a couple of weeks before use.

    Contrary to what has been written in some books Rodinal has always used the free base of p-Aminophenol although in the early days this was prepared from the Hydrochloride first.

    Ian

  2. #91

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    Quote Originally Posted by billtroop View Post
    and anyone who wants to know who Dr Shneour is has only to look him up on Google.
    I kept thinking that name looked familiar. I've seen it in Skeptical Inquirer magazine, a favorite of mine.

    Dr. Elie A. Shneour, is a biophysicist, the research director and head of the Biosystems Research Institute, the former chair and still member of the San Diego County Science Advisory Board, the author of numerous research and lay articles as well as several books. He serves in national level scientific capacities, is a member of a number of scientific societies, a founding chair of SDARI, and a CSICOP Fellow.
    http://sdari.org/event-archives-04.html

    So he has no actual connection with Agfa, but he simply did an analyis of the product...
    Last edited by Kirk Keyes; 08-27-2009 at 03:10 PM. Click to view previous post history.
    Kirk

    For up from the ashes, up from the ashes, grow the roses of success!

  3. #92

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    Quote Originally Posted by gainer View Post
    The batch I made yesterday is already showing signs of weakness. Two things come to mind. The water I used undoubtedly contained oxygen in solution.
    Pat - oxygen saturated water at 20C only contains 9.2 mg/L oxygen. First off, that's not much. Second, you can remove it by adding a pinch of sulfite to the water before dissolving they rest of your ingredients.
    Kirk

    For up from the ashes, up from the ashes, grow the roses of success!

  4. #93
    Photo Engineer's Avatar
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    Well, after some literature searching I find that you probably will not be able to make a stable Rodinal like concentrate from Metol. It is more active than pAP, enough so that the concentrate will probably not keep. Otherwise, the two compounds are quite similar differing only in the N-methy group in Metol.

    PE

  5. #94
    Ian Grant's Avatar
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    Quote Originally Posted by Photo Engineer View Post
    Well, after some literature searching I find that you probably will not be able to make a stable Rodinal like concentrate from Metol. It is more active than pAP, enough so that the concentrate will probably not keep. Otherwise, the two compounds are quite similar differing only in the N-methy group in Metol.

    PE
    And the form of the salt

    Only Edmund Lowe used the sulphate form of p-Aminophenol

    Ian

  6. #95
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    Quote Originally Posted by Ian Grant View Post
    And the form of the salt

    Only Edmund Lowe used the sulphate form of p-Aminophenol

    Ian
    The form of the salt is irrelevant in terms of keeping. The acid used to make the salt is probably only important in terms of the effect of the Chloride ion on development of some emulsions as I mentioned earlier.

    PE

  7. #96
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    Quote Originally Posted by Kirk Keyes View Post
    Pat - oxygen saturated water at 20C only contains 9.2 mg/L oxygen. First off, that's not much. Second, you can remove it by adding a pinch of sulfite to the water before dissolving they rest of your ingredients.
    A pinch? I thought that was against your religion. How many milligrams in a pinch?

    If I add anything before the metol, it will be a little ascorbic acid. That is to assure that any oxidized Metol that might be in my supply will be regenerated before I add the sulfite.

    I did just that a while ago. Metol, a healthy pinch of ascorbic acid, then enough KOH to form the Potassium Metolate. The usual usual flocculent precipitate never showed so I added sulfite. I still have only sodium.

    The resultig solution had little or no color. (my eyes are 82 years old, so I may not see the yellow end as well as some of you young squirts.) I did a test strip on EDU 400 Ultra. Not the best subject in the World, but it makes me want to go sit in that chair.
    Attached Files
    Gadget Gainer

  8. #97
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    P.S.
    8 minutes, 68 F, 1+25 seems to be a good starting place for this film.
    Gadget Gainer

  9. #98
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    After looking at Dr Shneour's credentials on the internet, and confirming with Bill Troop that this was indeed the same person, I come to the conclusion that he is indeed a respected individual in US chemistry circles with good credentials. I also find that Bill, at no point, said that Shenour was associated with Agfa.

    Therefore, Doctor Shneour's comments may be considered entirely valid as given to Bill in an interview. Any comments to the contrary may be irellevant. Dr. Shneour has been free to comment since the publication of the original FDC and has not done so and therefore I consider the matter closed as stands in Bill's comments.

    PE

  10. #99

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    Quote Originally Posted by Ian Grant View Post
    Ron, no-one is casting any doubts on Schneour's abilities or credentials, lets make that 100% clear. What I'm questioning is Bill Troop's use of his name in the FDC, when clearly none of us had ever heard of him in connection with Rodinal or any other developer.
    That's interesting, as I've apperently misunderstood the sentence in the FDC too!

    "Dr. Elie Schneour believes that the differences are not photographically significant."

    Dr Schneour's name was just blurted out in the book with no reference as far as I can see as to exactly who he is. One is left to beleive that he's an Agfa employee or some sort of Agfa insider. The only hint that may be otherwise is that he is listed in the acknoledgements as "researcher/photographer"...

    Instead, we find he's a guy that did a "spectrographic" analysis. That's a rather broad "type" of analysis.

    Bill, could you tell us more details on Dr. Schneour's analsis? Was it with IR, FTIR, UV, or Visible light? Was it an atomic absorption spectrophotometer or an inductively coupled plasma spectrophotometer? Did he analyze for anions as well, or just cations?

    By the way, I did an analysis for Total Organic Carbon and Ion Chromatography for anions for XTOL when it came out. Interested in the results of that? You can quote me in the next edition!
    Last edited by Kirk Keyes; 08-28-2009 at 01:23 AM. Click to view previous post history.
    Kirk

    For up from the ashes, up from the ashes, grow the roses of success!

  11. #100
    AgX
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    This thread is already very complicated and hard to follow. At least for me.

    I find this bickering very annoying.



 

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