Plastic material for holding chemicals? (Newbie question)

Discussion in 'Darkroom Equipment' started by carlostaiwan, Nov 3, 2017.

  1. Wayne

    Wayne Subscriber

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    No need to pay for them. My pharmacy will give empty cough syrup bottles away. I've discovered the gallon bottles dont really pour very well though. I think the narrow neck is designed for more viscous fluids like cough syrup.
     
  2. gary in nj

    gary in nj Member

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    I see that you are from Taipei, so I don't know if my suggestion will work for you. I use (reuse) bleach bottles because they are opaque and are made of thick material. They are sturdy enough that I can squeeze air out of them, allowing the chemicals to remain fresh for as long as possible.
     
  3. Mainecoonmaniac

    Mainecoonmaniac Subscriber

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    The enemy of developers and other phytochemicals are UV light and oxygen. Brown bottles block UV. Falcon years ago and collapsable photo containers to address both oxygen and UV. What I've been using are used collapsable wine boxes with the bladder. Wine is similar to photo chems because air and light can have adverse affects. I've been using them for years for developers. I'm a cheap wino so I plenty of them.

    Here's my drug of choice :wink:.

    https://www.traderjoes.com/fearless-flyer/article/2762
     
  4. Mainecoonmaniac

    Mainecoonmaniac Subscriber

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    Anybody remember Foster Brooks?

     
  5. PerTulip

    PerTulip Member

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    Go to a store that sells laboratory/medical/pharmaceutical supplies. They have every possible bottle/jug/container you will need, either clear or dark.
     
  6. DREW WILEY

    DREW WILEY Member

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    Get ahold of a catalog from an actual laboratory or scientific supply company to see charts comparing the various materials. Typical camera store plastic bottles and recycled soda bottles etc are good for only temporary use. Oxygen gets through. Only real glass bottles are reliable, preferably amber with an outer coating of protective plastic to minimize shattering if dropped. They don't cost much if you can find a convenient source.
     
  7. Michael Firstlight

    Michael Firstlight Subscriber

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    For folkd in North America, US Plastic - http://www.usplastic.com/?gclid=EAIaIQobChMIrcfDmZvC1wIVFCOBCh1QAQv9EAAYASAAEgKMffD_BwE Great selection, dirt cheap. I just bought 12 2L bottles and 2 5Gal bottles to outfit a new automatic processor I just bought (a sidekick), and the folks that service them referenced me to US plastic to get bottles for the chem at very low cost. For folks not in North America the shipping might negate the savings.

    MFL
     
  8. Kuby

    Kuby Member

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    Once the seal on the tap is cracked, do these wine bags continue to preserve developer for an extended period of time? I would love to be able to mix up my 6.5 litres of c-41 developer, store in wine bags in a box, and access exactly what I need every time I go to develop, with the added security that my developer will store for a long time (6-12 months, ideally).
     
  9. AgX

    AgX Member

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    The idea is to let the bags collapse during emptying so that there does not build up additional air volume on top of the fluid.
    And in contrast to those stiff plastic bellows containters the metal coating of the wine bellows yields lesser gas permeability.
     
  10. mgb74

    mgb74 Subscriber

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    As is often mentioned, those bellows type jugs work for a while - until cracks develop. At least you know as they no longer stay collapsed. Bulk coffee containers (the ones with the bladder that coffee shops use for groups) also work well. While they aren't intended to keep oxygen out over long periods, the heat resistant material they use does that as well.

    Whatever you use, don't forget the caps. I add rubber washers to the caps for a good seal. Hose washers fit great for reusing Sprint chemical bottles.
     
  11. Kuby

    Kuby Member

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    Yup, I understand the theory behind it, I'm just curious how well it actually works. They recommend drinking the contents of the bag within 45 days once the seal is cracked on the tap, I believe. I'll also mention that the wine bags we have here don't have a metal coating, but are see-through plastic.

    I'll probably find out soon enough how well this works because I'm going to try myself. I just wanted to hear about others experience with it.
     
  12. MattKing

    MattKing Subscriber

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    The wine bags come in two different versions.
    One version - made out of thin, metallic looking mylar - is excellent for this application, as it is relatively impermeable to oxygen.
    That version used to be common, but is now harder to find.
    The other version - made out of a translucent plastic material - is not nearly as impermeable to oxygen, and therefore isn't as well suited to this application.
    All the wine bags I see around here have transitioned to the latter material.
    Even the translucent plastic ones probably offer some benefits, but I would be careful with developers that have been stored in them.
     
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  14. Kuby

    Kuby Member

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    Interesting to hear this. Thanks.
     
  15. AgX

    AgX Member

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    That change was new to me too.
     
  16. Mainecoonmaniac

    Mainecoonmaniac Subscriber

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    I've stored XTOL which I use for replenishment for over a year it it seems fine. The bag collapses as the developer is dispensed.
     
  17. bernard_L

    bernard_L Member

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    Please quote your source. Why would more transparent to light mean more permeable to atmospheric gases? The permeability of polymers ranges over five (at least) orders of magnitude.

    See:
    http://www.soarnol.com/eng/solution/solution050723.html
    "As you can see from the graph, depending on the polymer type, the oxygen transmission coefficient changes one million-fold. Ethylene-vinylalcohol copolymer, which can be seen in the graph, has a thickness of about 10µm and is used for mayonnaise bottles. A thickness of 37cm is needed to obtain the same oxygen barrier properties with polyethylene."
    And quoting from Wikipedia (article on EVOH, ethylene vinyl alcohol):
    "The plastic resin is commonly used as an oxygen barrier in food packaging. It is better than other plastics at keeping air out and flavors in, is highly transparent, weather resistant, oil and solvent resistant, flexible, moldable, recyclable, and printable."
     
  18. AgX

    AgX Member

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    A polymer may contain added barrier substances (pigments) that reduce as well permeability as light transmission.
     
  19. MattKing

    MattKing Subscriber

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    It doesn't.
    It is just the way to easily tell them apart. And my observations are just that - observations.
    The mylar stuff seemed to work really well for lots of people when they re-used the empty bladders for photographic purposes - developers seemed to last for a long time.
    Since the wine box fillers switched to the translucent plastic for their wines, those who try to re-use them for photographic purposes seem to have less success. I expect that they are polyethelene.
     
  20. Tim Stapp

    Tim Stapp Member

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    I've used xtol mixed in steam distilled water stored in the translucent wine bladders last 18 months. I know, I need to shoot more :smile:
     
  21. iakustov

    iakustov Member

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    I store the stock solutions in JOBO plastic bottles and alike. When stored for more than a year, bottles with Ilford Bromophen stock leak (the color of the solution changes too, it is very dark). I guess this may be due to increased pH.
     
  22. Anon Ymous

    Anon Ymous Member

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    You mean they actually leak fluid out of the bottle? This sounds strange. I don't know the pH of stock bromophen, but I assume it's below 11, not excessively alkaline like sodium hydroxide solutions.
     
  23. iakustov

    iakustov Member

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    Yes, I noticed the bottle stuck to hardboard with dark taint on the bottom. Strange indeed.