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  1. #41
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    I refer you all to Haist, page 185, Volume #1

    PE

  2. #42
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    Well PE, I tried to request said book from my alma mater, who can get within a week or so any book from almost any university in Illinois, well, problem is that not one school has Vol I, I can find Vol II easily but Vol I is illusive. Can you paraphrase what Haist said?

    Ian - If you concede that there can be a difference of possibly weeks/months between A and B, is it not appropriate for one to suggest A is longer lasting than B if that is the question the OP posed? When each 1L of chemistry might cost a dollar or so, a month can matter and be akin to tossing $1 down the drain. If one can prevent wasting a dollar, a dollar saved is....

    Fwiw OP, I am a Liquidol user, I don't print frequently, I mixed up 1L this summer and printed maybe 3 sheets in it, then bottled it up and have not been able to print till yesterday, it worked just perfect.
    Andy

  3. #43
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    Quote Originally Posted by zsas View Post
    Ian - If you concede that there can be a difference of possibly weeks/months between A and B, is it not appropriate for one to suggest A is longer lasting than B if that is the question the OP posed? When each 1L of chemistry might cost a dollar or so, a month can matter and be akin to tossing $1 down the drain. If one can prevent wasting a dollar, a dollar saved is....

    Fwiw OP, I am a Liquidol user, I don't print frequently, I mixed up 1L this summer and printed maybe 3 sheets in it, then bottled it up and have not been able to print till yesterday, it worked just perfect.
    Quote Originally Posted by waynecrider View Post
    I need something that will last in the cupboard for quite awhile, say 2 years since I develop infrequently. I'd prefer not to mix anything as the scale is shot and that's that and I'd prefer a bottle of liquid developer. Thanks.
    Andy, my point is that all the PQ developers I've used have had a shelf life in exceess of the OP's 2 years, there's little point in the deliberate posts by some that deride formulae that have beenin use for around 60 years.

    You also have to discount comments from people with a commercial interest in their own product.

    Ian

  4. #44

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    From Haist regarding Phenidone B and Dimezone: "Both of these methylated Phenidone derivatives are more stable than Phenidone in concentrated liquid developing compositions that may be maintained at high temperatures or may be stored for long periods of time."

  5. #45
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    Thank you Michael, that's the point I've always made, and people trying to claim otherwise go against Haist, Mason and the senoir research chemists at Kodak, Ilford, Champion, Agfa etc. I did post Mason's comments in a previous thread which were probably more important as he was part of the team who worked on PQ developers.

    Ian

  6. #46
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    Basically, Phenidone is less stable than its chemical cousins, and that is stated in Haist. It goes bad in the concentrated form more rapidly.

    It also oxidizes more rapidly in alkali if O2 is present. The same protective groups that help the others in alkali, help them in oxygen.

    If you want a good concentrate with long shelf life, use Dimezone or Dimezone-S. If you want it to last long in the tray, same advice.

    PS. For those who have not guessed, I've done that experiment!. I can also add that Phenidone lasts a long time dry in coatings! It can be used as an incorporated developer. Done that too!

    PE

  7. #47
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    Quote Originally Posted by Ian Grant View Post
    Andy, my point is that all the PQ developers I've used have had a shelf life in exceess of the OP's 2 years, there's little point in the deliberate posts by some that deride formulae that have beenin use for around 60 years.

    You also have to discount comments from people with a commercial interest in their own product.

    Ian
    Hi Ian -
    I didnít realize that those who use science to support their option are supposed to be discounted should he/she have a commercial interest too. I guess I should thusly discount anything that Bill Gates has ever said too considering I use Windows. I also attended a professional convention that was led by a person who also wrote a book on the subject of the convention, I guess I should discount his opinion too?
    Now suppose one mixed up 1L of working solution of PQ based paper developer and 1L of lets say Liquidol. If the person then let them both sit on the shelf capped for 2 months, would they work equally well? I get the feeling that the PQ will not last as long, and therefore, might be consider longer lasting once mixed?
    Just because a bottle of developer can sit in concentrate a while is a good virtue, but shouldnít one also consider the mixed solution in his/her decision? I think so and want the OP to consider that. I donít print frequently and have no desire to put photochemistry in my freezer, and therefore, think that if I print a couple of prints in a 1L working solution and bottle it up and print again in say 2 months a couple more prints, I believe, could be wrong, that something like Liquidol (which mind you ships for FREE in the US) might just meet the OPís needs. Price, free shipping (from Amazon), are also in the algorithmÖ.
    Andy

  8. #48
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    Andy, they aren't using science, what they are doing is deliberately muddling the trade name Phenidone for the early version that never went into commercial production because it was unstable.

    So the scientists from Ilford & Kodak say Phenidone B and Dimezone are stable, and there are other stable versions of Phenidone and Dimezone, that's the science not the misleading comments.

    Ian

  9. #49
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    Interestingly enough, I tried to avoid my own interests and thus tried to "solve" the issue by referring to Haist, and then I tried letting someone else quote him. It seems that people will not even believe this venerable author's comments. And, outside of my interests, I spoke directly to Grant and others at EK in the time frame from about 1970 - 1985, before I started emulsion work, and the entire trend of developer design was towards Dimezone or Dimzone-S.

  10. #50
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    Quote Originally Posted by Michael R 1974 View Post
    From Haist regarding Phenidone B and Dimezone: "Both of these methylated Phenidone derivatives are more stable than Phenidone in concentrated liquid developing compositions that may be maintained at high temperatures or may be stored for long periods of time."
    Haist, Mason and others state Phenidone B and Dimezone plus other Phenidone derivatives are stable (Mason & GIP Levenson of Kodak list them) in alkali solutions. So I wouldn't disagreeing with Haist even remotely.

    Phenidone and Ilford's derivatives were Patented developing agent and so Kodak preferred to use Dimezones their own equivalent to avoid paying licensing/royalty fees, that side is being deliberately overlooked.

    It's simple Ilford used Phenidone and much later Kodak used Dimezone. Also Phenidone is a Trade name rather like Ektachrome or Tmax and there's different versions.

    Ian
    Last edited by Ian Grant; 01-09-2013 at 12:44 PM. Click to view previous post history.

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