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  1. #1

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    Alkaline stop bath + TF5 fix

    Anyone have any experience using Peter Hogan's alkaline stop bath?

    I'd like to use this for film development with TF5 fixer (which I believe is a neutral fix). The reason I would like to use the alkaline stop is it seems to be an ideal way around the "no-acid stop, water stop only" warnings for processing of film in staining/tanning developers.

    I hate using a water rinse to stop development. It requires a lot more volume than a stop bath, which complicates temperature control. Seems like Hogan's formula is pretty much the only commercially available alkaline fix on the market. Not sure what's in it.

  2. #2
    Photo Engineer's Avatar
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    Why use an alkaline stop? TF-5 is acidic! You can use an acid stop.

    PE

  3. #3
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    I'm curious how a stop like this would work. I thought that the "stopping" action was somewhat dependant on the acidity, since most developers work in an alkaline environment.

    Sincerely,

    Inquisitive in Kansas
    Last edited by holmburgers; 08-01-2011 at 11:59 AM. Click to view previous post history. Reason: woops, said acid when I ment alkaline
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  4. #4
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    Dear Inquisitive:

    Alkaline stop baths generally work by either oxidation of developing agents or inactivation of developing agents or by being able to "poison" the silver grains by means of a powerful restrainer. There are other methods to be sure, but these lead the pack so to speak. The first two can stain film or paper and the latter method can make the grains harder to fix. So, there are disadvantages to all of them IMHO. I have designed a few myself and even though they worked, I have been rather unhappy with all of them.

    PE

  5. #5

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    Quote Originally Posted by Photo Engineer View Post
    Why use an alkaline stop? TF-5 is acidic! You can use an acid stop.

    PE
    PE, shoot, I thought TF-5 was more on the neutral side. Maybe I should use TF4, or TF3?

    The idea is to use an alkaline stop and keep the process neutral to alkaline. Apparently (although not necessarily conclusively, and I guess also depends on the developer and film), an acid stop can remove stain. The stain issue is not my biggest concern. What bothers me is how with some developers the formulators warn you not to use an acid stop or you can get reticulation. I know this has been discussed before, but is that kind of a warning overstating the case? In this particular instance I'm referring specifically to Formulary TD-3, which I assume to contain either Pyro or Catechol. While some developers tell you vaguely to use a water rinse instead of a stop bath, the instructions for this tell you never to use a stop bath with it or risk reticulation. Strange

    So the question regarding TF5 was just because I want to make sure whatever fixer I might use for this particular process would be compatible with an alkaline stop.

    Although now that I read your response to Holmburgers, I'm wondering if an alkaline stop is a good idea at all.

  6. #6
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    You will have to make up your own mind about alkaline stops. I am merely stating a POV from that of a system engineer. Use of a stop should not cause reticulation with properly designed developers, fixes or photo materials. Specialty chemistry or photo materials are another matter though, as are individual work flows.

    All I can suggest is that you run tests. TF-5 is mildly acidic and can be used with either a running water rinse or an acid stop. TF-4 is alkaline and can be used with the same post development solutions as TF-5. They were designed that way.

    PE

  7. #7

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    Agree, although I must admit I'm inclined to go with an emulsion engineer's experiences with alkaline stops rather than making up my own mind

    I'm typically suspicious of specialty materials like this that require special treatment. Luckily my workflow is with straight forward stuff 99% of the time. But I'm trying a few experiments with TD-3 so it's probably worth trying with both a water rinse and stop bath. For the record I have never experienced any kind of problem with stop bath (reticulation, pinholes etc), so if it indeed makes a difference in this case that would be a first for me.

  8. #8
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    Dear Abb... I mean, Ron,

    Thanks!
    If you are the big tree, we are the small axe

  9. #9

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    Michael, I have used the alkaline stop for one bottle when I switched to alkaline fixer a while ago. I stopped using it, even though it is a perfectly good (albeit relatively expensive) product, because I became satisfied with water rinses. I use a staining developer for half my processing and a couple of 'regular' developers for the rest and don't miss having a stop bath for film processing. I use 3 water rinses and don't find a problem keeping a jug of a couple of litres of water for this at around 20-22 C: it's what I stand the fixer in anyway.
    Cheers, Mark Walker.

  10. #10

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    Quote Originally Posted by Photo Engineer View Post
    All I can suggest is that you run tests. TF-5 is mildly acidic and can be used with either a running water rinse or an acid stop. TF-4 is alkaline and can be used with the same post development solutions as TF-5. They were designed that way.
    So, not to go off topic too much, but what are the practical differences between TF-4 and TF-5? What are the cases when each would be preferable to the other? Based on what I quoted, I gather that TF-4 would be preferable for more damage-prone emulsions, and when maximum stain is desired from pyro-developed negs.

    But I have been using TF-5 for these things, at your recommendation. I thought I needed TF-4 for my PMK processing, but you said TF-5 would work just as well. I assumed that meant they were both alkaline fixers. And Freestyle/Formulary describe it as alkaline: http://www.freestylephoto.biz/030200...-make-4-Liters.
    Last edited by 2F/2F; 08-01-2011 at 05:09 PM. Click to view previous post history.
    2F/2F

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