Preserving Powdered Dektol

Discussion in 'B&W: Film, Paper, Chemistry' started by joeyk49, Nov 4, 2004.

  1. joeyk49

    joeyk49 Member

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    I picked up a 5 lb. can of Dektol (It was really cheap) but will only need a little at a time.

    What's the best way of preserving the unmixed powder after opening the can?

    Do I need to use light tight containers? Or, will zip type plastic bags do?
     
  2. KenM

    KenM Member

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    Splitting up dry chemicals is generally a bad idea, since the individual components may not be evenly mixed throughout the entire can. You could possibly mix the entire can at a higher concentration (it'll keep better), and then cut it from there, but having had no experience doing that, I'm not sure how well it'll work.

    If you're confident that the dry chemicals are well mixed, just divide it up and pack in air-tight containers. There will always be some air in the container (unless you remove it), so oxidation will occur, but perhaps the life will be extended.

    Good luck!
     
  3. glbeas

    glbeas Member

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    I've been that route and find that just resealing the bag in the box doesn't work unless you use the dektol pretty fast. But then there would be no reason to just mix part of it. Sealing it in airtight containers is good, especially if you can displace most of the air out of the container while doing it. I'm thinking maybe freezer bags, squeeze them down before sealing that last inch and put them away in the original box. If the powder turns brown on you just toss it, you won't like what it does to your prints.
     
  4. gma

    gma Member

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    I know that I have seen a thread about mixing concentrated liquid developers and freezing in small packets until you are ready to dilute for use.
     
  5. Loose Gravel

    Loose Gravel Member

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    Freezing your powders will help, too. Freezer bags help because they don't let the air through.

    I've used gallon bags a scoop at a time. Works okay. It would take me along time to use a 5 gallon lot.
     
  6. joeyk49

    joeyk49 Member

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    When the can arrived home, I took one look at it and said, "What was I thinking?!"

    I'm hoping the freezer bag thing works.

    Guess what developer I'll be using in my pin hole camera project with my Cub Scouts....
     
  7. Flotsam

    Flotsam Member

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    When I set up my current diminutive darkroom. One of my rules was to never mix chems in larger than 1 liter volumes. Of course I am too cheap to pay premium prices for the smaller packages so I buy Gallon packs and split them into quarts. I was amazed by how quickly and dramatically the Dektol discolored in a zip lock bag. Then I tried one of those vac 'n' seal machines which was better but surprizingly, the Dektolstill discolored in fairly short order. Now I use the vac 'n' seal and then put the individual packets into a zip lock bak and roll out the air. This seems to fit my needs although maybe I'll try storing in the freezer as was mentioned.

    My only point here is that Dektol is quite hard (but not impossible) to keep White once out of it's original packaging
     
  8. joeyk49

    joeyk49 Member

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    ...and another thread in this same catagory seems to indicate that discolored powder doesn't necessarily mean that its gone bad...

    I'm too cheap to throw out something that quite possible could be fine to use...I'll try the freezer and zip bags...