HCA and VC papers

Discussion in 'B&W: Film, Paper, Chemistry' started by philldresser, Dec 2, 2004.

  1. philldresser

    philldresser Subscriber

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    Reading the label on a packet of Kodak Hypo Clearing Agent that I bought today it states that you cannot use it with RC papers.

    Anyone know why?

    I sometimes use RC and Fibre and all go through the same initial rinse/wash cycle but the fibre get left in longer. I have not seen any side effects yet but would like to know what to expect.

    Phill
     
  2. Konical

    Konical Subscriber

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    Good Evening, Phill,

    I don't know about Kodak HCA (haven't used it in a long time), but Perma Wash bottles have instructions for RC processing. I routinely using a washing aid with RC, figuring that it might help and probably won't do any harm.

    Konical
     
  3. dancqu

    dancqu Member

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    Are you sure it says "cannot"? Dan
     
  4. Tom Hoskinson

    Tom Hoskinson Member

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    HCA is basically sodium sulfite or in some formulations sodium sulfite buffered with sodium bisulfite. I wouldn't think that it would be particularily harmful to RC Paper - though it won't do a whole lot of good, either. With RC you are basically concerned with washing a rather thin layer of emulsion.
     
  5. Ole

    Ole Moderator Staff Member Moderator

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    There are two good reasons for not using HCA with RC paper:

    RC paper is designed for minimum wet time. After a while the liquid starts to soak into the base through the edges, at which time the "advantage" is gone.

    It doesn't need it: Since the base doesn't absorb anything during the intended quick processing, there is no fixer to wash out of the base. The emulsion alone can be washed in a relatively short time - long before the water starts soaking in.

    So in the interest of keeping wet times down, HCA is not recommended. And if you DO use HCA, you'll need a longer wash to get the HCA out of the (now soggy) RC base.
     
  6. philldresser

    philldresser Subscriber

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    So if reduction of soaking is the prerequisite of RC should I be concerned that during my sessions I leave the prints for upto 4 hours soaking in still water whilst I make more. I wash at the end of the session

    Phill
     
  7. Lee Shively

    Lee Shively Member

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    Four hours may be excessive, still I have been know to use a wash aid on RC papers and I've had them in solutions for extended periods of time.

    It also may depend on the paper you are using. I've found that Ilford RC papers are very robust in regard to wet time. I often leave them in the wash for 10-15 minutes and then go through toning and rewashing without any apparent problems. I've even used extended times and high temperature solutions of Kodak Brown Toner and Nelson Gold Toner with Ilford warmtone RC paper. The papers may be absorbing chemicals around the edges and problems may show up later but nothing is readily apparent currently. Ilford RC is the only RC paper I've had any real experience with in recent years so other RC papers may not respond as well.
     
  8. philldresser

    philldresser Subscriber

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    Lee

    I use Ilford multigrade, graded and Oriental Seagull RC papers. So far I have had no issues with the long soaks but I think I will change my methodology so as not to tempt providence.

    Phill
     
  9. Bruce Osgood

    Bruce Osgood Membership Council Council

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    For RC paper there is no need for a wash aid. Can't hurt but really a waste of time and chemistry.

    the emulsion of RC paper does not allow chemistry to penetrate the surface as does FB paper. After Fixing a 10 to 15 minute wash in running water is all that is needed. As Ole and others have pointed out, the less wet time the better.

    Bruce (Camclicker)