Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 68,691   Posts: 1,482,393   Online: 799
      
Page 1 of 2 12 LastLast
Results 1 to 10 of 11
  1. #1
    Snapshot's Avatar
    Join Date
    Jan 2007
    Location
    Toronto, Ontario, Canada
    Shooter
    Multi Format
    Posts
    793

    Frozen Phenidone Anyone?

    Hi All,

    I was wondering if phenidone can be frozen in order to extend it's useful life. It's my understanding that phenidone can lose potency over time in powder form. Will freezing it extend it's useful lifespan? I can make a solution of alcohol or glycol but I would prefer to avoid doing this.

    Any input would be appreciated.
    "The secret to life is to keep your mind full and your bowels empty. Unfortunately, the converse is true for most people."

  2. #2
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    15,947
    Images
    148
    Phenidone keeps very well in powdered form. In my own experience the Phenidone I finished last year which had an Ilford manufacture code stamp for 1966 was just as good as the fresh Phenidone I'm using now. There was definitely no deterioration.

    I certainly wouldn't recommend freezing.

    Ian

  3. #3

    Join Date
    Nov 2004
    Shooter
    Multi Format
    Posts
    2,048
    I've frozen glycin for the short term, no problems and I've been using the same batch of unfrozen phenidone for 4 years, (I just don't use phenidone much) again, with no problems. It should last quite awhile as is.

    I believe you can mix it with TEA, but you'd need Tom Hoskinson, Pat Gainer or another of that group who's actually done that to confirm it.

  4. #4

    Join Date
    Mar 2004
    Location
    Southern California
    Shooter
    Multi Format
    Posts
    3,879
    Images
    11
    Quote Originally Posted by jim appleyard View Post
    I've frozen glycin for the short term, no problems and I've been using the same batch of unfrozen phenidone for 4 years, (I just don't use phenidone much) again, with no problems. It should last quite awhile as is.

    I believe you can mix it with TEA, but you'd need Tom Hoskinson, Pat Gainer or another of that group who's actually done that to confirm it.
    Similar to Ian's experience, I am still working with a batch of Ilford Phenidone that I bought in the 1960s. My Phenidone dry powder has been stored in tightly sealed amber glass rounds the whole 30 odd years and it is in great shape.

    I do keep a bottle of Phenidone stock solution (i.e. Phenidone dissolved in Propylene Glycol) for measuring convenience, when measuring out small quantities of Phenidone.

    Phenidone dissolves easily in Triethanolamine, but the resulting mixture is very high in viscosity and difficult to measure out.

    I don't mix Phenidone stock solutions in Iso-Propyl Alcohol because it is a notorious water molecule grabber (hydroscopic) and thus enables oxidation of the Phenidone.
    Last edited by Tom Hoskinson; 12-19-2007 at 11:33 AM. Click to view previous post history. Reason: typo
    Tom Hoskinson
    ______________________________

    Everything is analog - even digital :D

  5. #5
    Snapshot's Avatar
    Join Date
    Jan 2007
    Location
    Toronto, Ontario, Canada
    Shooter
    Multi Format
    Posts
    793
    That's contrary from what I've been reading in the "The Film Developing Cookbook". The authors indicate that phenidone can start to lose potency in a year, although it can be still used for print developers. However, if you are seeing no loss of potency then that's good enough for me. Some of you have phenidone that is older than me.
    "The secret to life is to keep your mind full and your bowels empty. Unfortunately, the converse is true for most people."

  6. #6

    Join Date
    May 2005
    Location
    Woonsocket, RI USA
    Shooter
    35mm
    Posts
    2,725
    Quote Originally Posted by Snapshot View Post
    That's contrary from what I've been reading in the "The Film Developing Cookbook". The authors indicate that phenidone can start to lose potency in a year, although it can be still used for print developers. However, if you are seeing no loss of potency then that's good enough for me. Some of you have phenidone that is older than me.
    Are you sure that A&T are talking about the powdered form? My understanding is that it deteriorates fairly rapidly in water solutions, but not in powdered form. Dimezone S (a phenidone variant) is said to last longer in solution than phenidone, which is why it's used in most (maybe all) commercial developers that are commonly said to use phenidone (such as XTOL). To the best of my knowledge, though, powdered Dimezone S doesn't last longer than powdered phenidone. I've got some Dimezone S that's about three years old, and it seems to be working as well now as when I got it.

  7. #7
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    15,947
    Images
    148
    Don't believe all you read in "The Film Developing Cookbook" It contains a lot of errors and mistakes. I've never seen anything elsewhere about Phenidone losing its potency, quite the opposite PQ developers have a far better shelf life than a similar MQ developer.

    I was using 40 year old Phenidone for print and negative developers, and my Pyrocat HD negatives have been superb.

    Ian

  8. #8
    Snapshot's Avatar
    Join Date
    Jan 2007
    Location
    Toronto, Ontario, Canada
    Shooter
    Multi Format
    Posts
    793
    Quote Originally Posted by srs5694 View Post
    Are you sure that A&T are talking about the powdered form? My understanding is that it deteriorates fairly rapidly in water solutions, but not in powdered form. Dimezone S (a phenidone variant) is said to last longer in solution than phenidone, which is why it's used in most (maybe all) commercial developers that are commonly said to use phenidone (such as XTOL). To the best of my knowledge, though, powdered Dimezone S doesn't last longer than powdered phenidone. I've got some Dimezone S that's about three years old, and it seems to be working as well now as when I got it.
    I thought that's what I thought was indicated in their book. However, it was for stock solutions and I'm might be mistaken that it also applies to powder shelf life. Phenidone my not keep well in stock solutions but, obviously, it does keep well in powder form. Let me double check the book to see if I just misremembered what was stated.
    "The secret to life is to keep your mind full and your bowels empty. Unfortunately, the converse is true for most people."

  9. #9

    Join Date
    Mar 2004
    Location
    Southern California
    Shooter
    Multi Format
    Posts
    3,879
    Images
    11
    Quote Originally Posted by Snapshot View Post
    I thought that's what I thought was indicated in their book. However, it was for stock solutions and I'm might be mistaken that it also applies to powder shelf life. Phenidone my not keep well in stock solutions but, obviously, it does keep well in powder form. Let me double check the book to see if I just misremembered what was stated.
    Phenidone keeps very well in dry powder form and in properly designed stock solutions (like phenidone dissolved in Propylene Glycol). My statements can easily be verified by testing - and have been verified...
    Tom Hoskinson
    ______________________________

    Everything is analog - even digital :D

  10. #10
    gainer's Avatar
    Join Date
    Sep 2002
    Posts
    3,726
    Images
    2
    The worries you may have about alcohol, either for humans or phenidone, do not apply to propylene glycol, which you will see on lists of ingredients of things to be swallowed by or rubbed on humans.
    Gadget Gainer

Page 1 of 2 12 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin