Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 68,678   Posts: 1,482,074   Online: 724
      
Page 7 of 7 FirstFirst 1234567
Results 61 to 66 of 66
  1. #61

    Join Date
    Sep 2002
    Location
    Willamette Valley, Oregon
    Shooter
    Medium Format
    Posts
    3,684
    Quote Originally Posted by Jordan View Post
    Bill, I think Dan's point is that whether Kodak
    made an alkaline fixer at one time or not, alkanolamines
    are still poor buffering agents for acidic fixers, and
    Ryuji's "In such formulae" referred to acid fixers.
    That is correct. The two posts in question are Ryuji's #49
    and Troop's #51. Troop's post presents a split paragraph
    which occurs approximately mid Ryuji's post. Troop's
    "Nonsense" caught my attention so I checked it
    out. In context, not at all nonsense. Dan

  2. #62

    Join Date
    Aug 2005
    Shooter
    Multi Format
    Posts
    117
    Quote Originally Posted by dancqu View Post
    That is correct. The two posts in question are Ryuji's #49
    and Troop's #51. Troop's post presents a split paragraph
    which occurs approximately mid Ryuji's post. Troop's
    "Nonsense" caught my attention so I checked it
    out. In context, not at all nonsense. Dan
    Dan, you have missed the point, but I think I now understand why, so let me explain.

    The sentence that I omitted in the quotation states:

    "Also, triethanolamine has no buffering capacity or fixing accelerating effect in such a low pH range."

    With this sentence I have no argument. It states that TEA does not have buffering capacity or accelerative effect at low pH range, i.e., the acid range that Ryuji erroneously claims all Kodak fixers are formulated for.

    What I argue with are the two parts that I included. Here he states that (a) Kodak never used alkaline fixers and therefore (b) never studied the effects of alkanolamides in alkaline fixers.

    Both parts of the this statement are untrue, as I both state and as Ron Mowrey confirms in a later post.

    Ryuji's statement that TEA has no useful buffering or accelerative effect at low (i.e. acid) pH range (he should have been more precise) is true, but it is irrelevant to the correction I made. Hence, since it had nothing, whatever, to do with my point, I omitted it.

    Please let me know if this is still not clear. I always omit parts of quotes that are irrelevant or confusing ... I am sorry that, in this case, it has added to confusion.

  3. #63

    Join Date
    Sep 2002
    Location
    Willamette Valley, Oregon
    Shooter
    Medium Format
    Posts
    3,684
    [QUOTES=billtroop;439810]
    "The sentence that I omitted in the quotation states:"

    ""Also, triethanolamine has no buffering capacity or fixing
    accelerating effect in such a low pH range."" RS

    Correction: Your quote does include that sentence. Post #51

    "What I argue with are the two parts that I included.
    Here he states that (a) Kodak never used alkaline fixers ..."

    Correction: Ryuji: "...all fixer products Kodak offered in the
    past and present .... are adjusted to acidic pH." So they never
    "Offered" alkaline. Your statement; "Kodak has not offered
    alkaline fixers to the public but started using them in
    machine processing ..." So what's the beef?

    Reminds me of the large regional processing labs of 50
    years ago. So 50+ years ago Kodak did Use an alkaline fix.
    My guess, no way an 'offering. We were left out.

    "...and therefore (b) never studied the effects of
    alkanolamides in alkaline fixers."

    I don't see anywhere in the paragraph, split in post 51,
    any wording by RS stating or implying that Kodak did not
    study the effects of alkanolamides. He does say they
    "...never had any reason to use ..." them in fixers.
    And why? Because they are "... useless in acid
    fixers" Kodak's only public offerings. Dan

  4. #64
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    22,708
    Images
    65
    Dan;

    Kodak offered alkaline fixes for many years from the 50s through the 60s for commercial use in some processes and up to about the 90s in X-ray processes using a glutaraldehyde hardener. The commercial color process was offered in a home color kit called P-122. You were not left out, you were probably in diapers then. P-122 lasted a long long time.

    Bill knows this and was basing his remark on this.

    I have given the known reasons for abandoning these.

    The latest Kodak patents on TEA and alkaline fixers date to the mid 90s. This work was never realized and Bill knows this as well. The patent was issued, but the product was never released. I think that is a point to consider here, that Kodak had an ongoing program investigating alkaline fixes to reduce the amount of water needed for washes among other things.

    I assure you, and have posted this, that since they sold alkaline fixes, and studied TEA, they had a reason to use them, but chose not to and chose to discontinue those that they did offer.

    There were reasons for not using TEA, but I cannot remember them and discussions with Grant Haist have not uncovered the reason. His memory and mine coincide but the reason escapes both of us.

    I have been studying image stability for over 30 years on and off, and have had extensive discussions with Henry Wilhelm on this subject. I took the ICIS course in image stability by Jon Kapecki a year ago. There is, unfortunately, no current or existing new work on B&W image stabilty except for the Ctein work and others such as Beveridge of Ilford cited here. It pretty much ceased in the mid 80s. We cannot comment definitively one way or the other on the effects of TEA in a fixer.

    Your apparent contention that Kodak and others AAMOF, only offered acid fixers to hobbyists is wrong. Alkaline fixers have been known for years and Grant Haist was merely the conduit for publication of the information in the 70s. I know this clearly, as I helped edit his book at EK at the time.

    PE

  5. #65

    Join Date
    Sep 2002
    Location
    Willamette Valley, Oregon
    Shooter
    Medium Format
    Posts
    3,684
    Quote Originally Posted by Photo Engineer View Post
    Dan; Your apparent contention that Kodak ... PE
    You've got the wrong guy. That is Mr. Troop's contention.
    I've only quoted what he has said; post 51. "Kodak has
    not offered alkaline fixers to the public ..." Machines
    yes, public no.

    Of course it's good news if true. It is an endorsement
    of the alkaline fix. With emulsion incorporated hardeners
    there is less need for acid fixers. Odd they should drop
    their offerings of alkaline fixers. Dan

  6. #66
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    22,708
    Images
    65
    Dan;

    Bill also referred to my earlier post that Kodak had offered alkaline fixers for general sale. I wish to correct one thing I said. When P122 converted to the alkaline fix it was marked Ektaprint-C in trade dress. He is aware of what they sold and who they sold it to. He incorporated my comments by reference in his posts.

    Bill is also aware that Kodak chose to remove them from the market. Alkaline sodium based fixes were too slow and ammonium fixers had an objectionable odor. They would not use TEA for some 'forgotten' reason even though research continued on TEA until the 90s. Instead, they developed the neutral pH (pH 6.5) series of fixes and used other means to accelerate both fix rate and wash rate. This work started in 1965. I was a member of a team that did the color work and Grant worked in the B&W area. That is how I first met Grant.

    Grant explained most of this to Bill when Bill was writing his portion of the A&T book. I know it because I was there for the full term of the research, part as a member and part on the outside observing from other projects. Keith Stephen's office was about 4 doors down from mine. We talked often until his untimely death.

    I used to test samples of these novel fixers, and novel fixing agents. I used to do 'homework' here in my own darkroom at night testing fix rate on film strips. I can tell you, among other things, that the original formulas for many of the fixes and blixes looked quite different from the first to the last iteration. This is for safety, cost and method of manufacture. All of those factors and more enter into the selection of a final formula.

    PE

Page 7 of 7 FirstFirst 1234567


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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