Pyro-washing aid?

Discussion in 'B&W: Film, Paper, Chemistry' started by rcovingt, Dec 10, 2008.

  1. rcovingt

    rcovingt Member

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    I hope this isn't to stupid of a question:

    I have used HC110, and Kmax--to date.

    As I am researching developers trying to find one that will meet my personal tastes and do well with a Jobo. I have found that PMK Pyro or the Rollo Pyro may be my next thing to try.

    It is my understanding that these are staining developers? With that being said is it advisable to use a washing aid with these developers for fear of putting "streaks" in a stain that may not be set yet....

    I ask because of the recomendation to use an alkaline fixer and I wanted to make sure there was no other subtle things I may need to know about this developer.

    Again any additional understanding you can offer will be appreciated

    Best regards

    Robert
     
  2. Ian Grant

    Ian Grant Subscriber

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    Wash aid isn't necessary with films so there's no problem. It's most beneficial for Fibre based papers.

    Ian
     
  3. jim appleyard

    jim appleyard Member

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    It is my understanding that wash aids are primarily sodium sulfite; sulfite reduces the amount of stain in a negative, not a good thing if you're going to the trouble of using a staining dev.

    An alkaline fix (TF-3, mix yourself or TF-4 from the Formualry) is highly recommended for use with staing devs as they don't contain much sulfite and by using an alkaline fix, it washes out much faster than an acid fix and therefore you don't need to use a wash aid.
     
  4. cdholden

    cdholden Member

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    If you're going the Pyro route, why not HD? I understood that to be more reliable with rotary developing than the others. I've got the kit to try out the HD myself, just haven't had time from the grind to try it out.
    Best of luck.
     
  5. Jim Noel

    Jim Noel Member

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    I agree. I have used Pyrocat HD for the last few years after several years with PMK and Rollo Pyro. The HD is better for my work and I like that it stains primarily the image and not the overall negative. I use it both in a Jobo and in a tray for negatives up to 7x17.
     
  6. erikg

    erikg Member

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    I also agree. I switched from rollo pyro to HD a couple three years ago and find it superior both for the work I do and in terms of ease of use, evenness of development and staining. It also keeps well and is easy to use in trays and tanks as well. I use a wash aid but I can't say that I can see a difference when I just wash with water. I don't think you have to worry about that.
     
  7. Philippe-Georges

    Philippe-Georges Member

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    I use Sandy King's Pyro-HD and, after two alkaline fixing baths and a little pre wash, I treat the film for 2 min. in K.H.C.A. and never experienced any 'damage' of the stain.
    I recall reading somewhere on a forum that hypo clearing might not be necessary wit alkaline fixing after Hypo developing. But I have never, unless I missed it, read any confirmation about this by a 'connoisseur' (do not interpret this expression as a sarcastic remark or a lack of respect!).
    And, if there is really no need for K.H.C.A. (or 2% Sodium Sulfite) in the B&W film (Pyro-) process (or after fixing FB paper in alkaline fixer), I will gladly omit it.

    Thanks,

    Philippe
     
    Last edited by a moderator: Dec 11, 2008
  8. Ian Grant

    Ian Grant Subscriber

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    Philippe, HCA is really more beneficial when used with Fibre based papers. This is because some of the equilibrium products formed between the silver halides and the thiosulphate are only slightly soluble and can form weak links with the cellulose in the paper base. With fresh fixer this isb far less of a problem, but with partially used or exhausted fixer these silver-sulphur complexes remain in the paper, particularly in the base. This is the reason that many people use dual bath fixing for fibre based papers. It's these intermediary complexes that cause staining etc on poorly fixed prints. The chemistry is quite involved as there are many possible intermediary complexes that can form.

    A wash aid, (HCA or 2% Sodium Sulphite or Carbonate, or a mix), helps to tip the equilibrium balance towards soluble complexes which significantly improves the washing process.

    It's easier to wash the complexes from film, & RC papers where there's no contact with the actual paper (cellulose) in the base. An HCA bath will cut washing but not by a very significant amount, and wash times for films & RC papers are relatively short anyway.

    Ian
     
  9. erikg

    erikg Member

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    On the other hand, an HCA does seem to help clear out the AH dye in the TMax films faster, so I keep it in the process.
     
  10. jim appleyard

    jim appleyard Member

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    Check out Anclell's "Darkroom Cookbook", there's plenty in there about staining devs. The "damage" might not be something you'd notice until you compare the stain with film processed in pyro w/o sulfite.
     
  11. sanking

    sanking Member

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    BTW, the Third Edition of the "Darkroom Cookbook" was published this year. Pages 58-70 are devoted to pyrogallol and pyrocatechin developers, with pages 68 and 69 about Pyrocat-HD and Pyrocat-MC, and page 70 has a print by me of the interior of an old mosque in Edirne, Turkey, that was developed in Pyrocat-MC for N-2. The negative was HP5+, 6X9Cm.


    Sandy King


     
  12. jim appleyard

    jim appleyard Member

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    Sandy, thanks for the update. I look forward to reading it. I should be unwrapping it on x-mas morning. (I've been a good boy all year! Really!)