Making my own dry D-72 packets

Discussion in 'B&W: Film, Paper, Chemistry' started by tkamiya, Jan 17, 2013.

  1. tkamiya

    tkamiya Member

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    I wonder if this is feasible...

    I'm going to mix my own Dektol (D-72) from scratch. I have a question about the process.

    I know the basic method of mixing such from scratch is, I go from top of the list and start adding components. Dissolve one completely then go to the next step. Then I thought... Dektol comes in one package already mixed. Can I create a powder mix first and just add water like I would with pre-packaged Dektol?

    For the same reason, can I mix up dry chemicals, seal it in a bottle for one shot quantity or create a foil packaged/heat sealed one per serving packet? The mix doesn't decay if I keep it away from oxygen and not add water, correct? I'm envisioning one packet per serving type thing.... To avoid uneven mixing, I will measure each packet separately.
     
  2. Michael R 1974

    Michael R 1974 Subscriber

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    PE would know better than me for sure, but I would assume there must be some additional compounds in Kodak's single packets that not only allow all the main ingredients to be stored together, but also allow them to go into solution together.

    Regarding storage, note that Ilford's equivalent MQ film and paper developers are packaged in two packets.

    Regarding mixing, for example, my understanding is that Metol will not readily dissolve in Sodium Sulfite solutions. This is why whenever both Metol and Sodium Sulfite are called for, the standard mixing practice is to dissolve only a pinch of Sulfite (to scavenge some Oxygen) before dissolving the Metol. The rest of the sulfite must go in at some point after the Metol is dissolved.
     
  3. Bob Carnie

    Bob Carnie Subscriber

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    If you get a price for metol , would you let me know where , I am looking for 25 lb quantity, I have tried my local supplier and am getting a quote from Artcraft.
    I am making my own as well, I would suggest you could make a stock solution . I keep mine in a 20 litre container and it lasts for the time lines I work in.
    I have kept all my Ilford multigrade 5 litre containers so I can mix 30 - 40 litres at a time of stock and use as I go.

    I would be very interested how far you go down this wormhole and then I would like to steal your idea.

    Bob
     
  4. tkamiya

    tkamiya Member

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    Bob,

    I got my metol from Adorama which sells Photographers' Formulary products. 100 gram jar I bought was 13 dollars. I see one pound jar is about $50 right now. My needs are so small compared to yours, so I do not have the price for quantity advantage. It was just convenient to buy from this source along with my other stuff.

    If I do not get a definitive answer here, I am going to just mix up my powders and keep it in a jar for 6 months and see what it does. My printings are very sporadic. "Per shot" packaging may work well for me if I can get that to happen.
     
  5. tkamiya

    tkamiya Member

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    Calling PE... calling PE... come-in, PLEASE!
     
  6. jim appleyard

    jim appleyard Member

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    PE can chime in better than I can, but there's something in Anchell, Anchell/Troop about metol going bad with sulfite in the same mix.
     
  7. Bob Carnie

    Bob Carnie Subscriber

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    Fyi I just got a great price from Mike at ArtCraft on Metol and Hydroquinone.
     
  8. nworth

    nworth Subscriber

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    Pre-measuring components for darkroom solutions is very handy and effective. I use it for fixers, but that's all.

    For developers, remember that you must keep the metol separate and dissolve it first. Metol forms an insoluble aduct with sulfite. That is solved in commercial developers by special coatings, but you can't do that at home. So preparing packets to mix up D-72 is quite practical, but you will need two packets. If you want an single packet, you might look to a phenidone based developer, which doesn't have this problem.
     
  9. tkamiya

    tkamiya Member

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    So, I can make a small packet of Metol and let it be packet A, then everything else as packet B.

    Would this work with THIS recipe?

    Water at 50c 750ml
    Metol 3g
    Sodium Sulfite (anhydrous) 45g
    Hydroquinone 12g
    Sodium Carbonate (monohydrate) 80g / (anhydrous) 66.64g
    Potassium Bromide 2g
    Water to make 1000ml
     
  10. Gerald C Koch

    Gerald C Koch Member

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    The answer is NO unless you keep the sodium carbonate separate from the Metol and hydroquinone. Even doing this will not guarantee that the mixture does not eventually turn brown. D-72 contains 5 ingredients you should be able make a batch of solution in less than 10 minutes.
     
    Last edited by a moderator: Jan 17, 2013
  11. tkamiya

    tkamiya Member

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    Waaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa!
     
  12. tkamiya

    tkamiya Member

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    I wonder how Kodak solved these two problems.... Dektol comes in one packet all mixed up. Did they coat chemical granules so they dissolve in the right order AND doesn't interfere from some not dissolving because something else is already in the solution??
     
  13. Gerald C Koch

    Gerald C Koch Member

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    Kodak spent a lot of money and time on research to come up with a single powder mix. Kodak has many patents on this problem. This is why Ilford's ID-11 comes in two bags but D-76 comes in just one. Each chemical may need a different approach. For example, very finely divided boric oxide is used to coat such alkalies as sodium carbonate. All the chemicals must be completely anhydrous. Even a small amount of moisture will cause the powder mix to spoil. The chemicals are also packaged under nitrogen.

    When Acufine first appeared the cans started exploding on the store shelves. The developer had to be reformulated.
     
    Last edited by a moderator: Jan 18, 2013
  14. Rudeofus

    Rudeofus Subscriber

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    To get some perspective look at this catalog of photo chemicals from some German supplier, and take note that Kodak most likely has a stash of muchmore convoluted and obscure and diverse compounds ready to use but which they won't trade publicly. If you can formulate and make modern fine grain ISO 400 color negative film, formulating one part D-76 is trivial in comparison.

    This likely means we can't do this in our kitchen with supplies form Artcraft and Formulary. Sometimes we amateurs have to improvise, and mixing D-72 from two or even three powder parts and water seems not that much of a hassle.