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Thread: Use of inert gases

  1. #21
    Drew Wiley
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    Re: Use of inert gases

    Carbonic acid - I was retouching a print today of a dawn shot of a marble cliff in Kings Canyon, taken two weeks ago, where over 240 caves have now been identified. Most of this acid comes from decaying vegetation. The problem with the acidification in the oceans, due mostly to atmospheric CO2, is that it has the potential for super-additive increase. Those very microorganisms, corals, and mollusks which effectively trap carbon to create shells or exoskeletons, and over time have created limestone, are now having a very difficult time forming their calcareous shells or branches due to oceanic pH shift. It's gotten so bad that many of our West Coast oyster farms have had to import the early stage of their oysters, or raise them in controlled pH tanks until their tiny thin shells are thick enough to resist the acidic corrosion. Back when my wife and I were taking our honeymoon, we traveled to Kauai in a airline 3-seater next to a lady who was a Coca Cola executive. My wife asked her if she got her Coke for free. She responded that she never drank the stuff because every ingredient is shipped in Hazmat tank cars, esp the concentrated carbonic acid. Everybody knows what carbonized drinks do to teeth !

  2. #22

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    Re: Use of inert gases

    I use old 2 liter soda bottles. I squeeze all of the air out of them and tighten the cap down when the liquid reaches the top. I generally replace them every time I mix up new chemistry, so I don’t have issues with them leaking air or liquid. Since I already have them on hand, they only cost me the time it takes to wash them out. I even use different shaped bottles (Coke, Dr. Pepper, Sprite, etc.)for different chemicals, which proved handy once when I accidentally poured out a tray of fixer, thinking it was the wash tray in the dark. It was easy to refill with the right chemical without turning on the lights. I’ve had D76 last 8 months in those bottles. It may even last longer, I haven’t had the opportunity to test it.

  3. #23
    Drew Wiley
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    Re: Use of inert gases

    Yeah, soda bottles are now made of better plastic than so-called darkroom bottles (though you can get serious plastics from actual lab supply companies). Of course, the trade-off is that all those new soda and water bottles take forever to decompose.

  4. #24

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    Re: Use of inert gases

    Quote Originally Posted by jim10219 View Post
    I use old 2 liter soda bottles.
    Be careful....if the solution contains Sodium or Potassium hydroxide (1 to 10%) you can get problems, if the bottle is made of PET see "Polyethylene Terephthalate (PET)--Chemical Compatibility" https://roboworld.com/wp-content/upl...patibility.pdf
    So far I have seen most e.g. developer solutions are made without NaOH or KOH but a few have it: For example Part B of "Pyrocatechin Compensating Formula" or "AGFA Rodinal - Original Version" with 20% concentration see http://www.danieldevinephotography.com/?p=4317

    Bj68

  5. #25

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    Re: Use of inert gases

    I can tell from first-hand experience that ldpe bottles (eg used for soft drinks) will be dissolved by Fuji RA4 developer. HDPE will work fine though.

    As to the Coca cola: as far as I know the acid is added in the firm of phosphoric acid. It's a great rust cleaner. Carbonic acid has a pka of only 6.36 and therefore is by far not acidic enough to give coca cola its acidity, nor is it likely to interfere very badly with the pH of a developer.

  6. #26

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    Re: Use of inert gases

    Quote Originally Posted by BJ68 View Post
    Be careful....if the solution contains Sodium or Potassium hydroxide (1 to 10%) you can get problems, if the bottle is made of PET see "Polyethylene Terephthalate (PET)--Chemical Compatibility" https://roboworld.com/wp-content/upl...patibility.pdf[/url]
    Bj68
    This theory is not directly applicable to BW darkroom regular chem, because the caustic agent is not alone, forming a tampon.

    An easy example: a PET bottle with Sodium hydroxide can also contain a certain acid to form a salt, say sea water.

    So a RA-4 developer may disolve PET (Koraks), while high content of Sodium hydroxide in the formula may not determine that.


    Quote Originally Posted by koraks View Post
    I can tell from first-hand experience that ldpe bottles (eg used for soft drinks) will be dissolved by Fuji RA4 developer. HDPE will work fine though.

    As to the Coca cola: as far as I know the acid is added in the firm of phosphoric acid. It's a great rust cleaner. Carbonic acid has a pka of only 6.36 and therefore is by far not acidic enough to give coca cola its acidity, nor is it likely to interfere very badly with the pH of a developer.
    Xtol preserves very well inside soda bottles.


    _________________________________________-

    Please, if using food containers to store chem please label it very well (and permanent) with skull and bones, and keep out of the reach for other people, later wash and destroy the container, for disposal.
    Last edited by Pere Casals; 25-Oct-2018 at 00:52.

  7. #27
    Drew Wiley
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    Re: Use of inert gases

    The skull and bones symbol probably belongs on two thirds of what people drink from those bottles to begin with!

  8. #28

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    Re: Use of inert gases

    Quote Originally Posted by Drew Wiley View Post
    The skull and bones symbol probably belongs on two thirds of what people drink from those bottles to begin with!
    Sure!

  9. #29
    Jac@stafford.net's Avatar
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    Re: Use of inert gases

    Several years ago I bought a large tank, with spout, said purpose was specifically for storing water. Then over a couple month's I deposited water from my home distiller until it was full. Circumstances caused me to leave film process for about 18 months, and when I finally went to the tank it was empty!

    Oh, I keep the room under 50% humidity, with the atmospheric water draining into the city system.

    Something to think about.

  10. #30
    Peter De Smidt's Avatar
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    Re: Use of inert gases

    What about duster products, such as Dust-off and similar? Most seem to have 1,1-Difluoroethane.
    “You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
    ― Alexander Den Heijer, Nothing You Don't Already Know

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