How do I mix small amounts of Formulary Hypo Clear Agent

Discussion in 'B&W: Film, Paper, Chemistry' started by ElenaH2O, Jan 25, 2012.

  1. ElenaH2O

    ElenaH2O Member

    Messages:
    4
    Joined:
    Dec 26, 2011
    Shooter:
    Multi Format
    I purchased a package of hypo clear agent (it is powder), I would like to use small batches of this. The package I purchased has 200g sodium sulfite and 2g sodium bisulfite. According to the instructions it recommends mixing 750ml of warm water(125 degrees F) with sodium sulfite first and desolve and then add the sodium bisulfite next, then add cold water to make a total of 1000ml to create a stock solution. Then it recommends mixing from the stock solution a 1:9 ratio. I have been unable to find anything as to how long this stock solution would last. From what I have found it is recommended that it be mixed and then thrown out. Does anyone have suggestions for mixing smaller batches. Any help is appreciated, as I am new to the chemical mixing.

    Thanks Elena
     
  2. Ian Grant

    Ian Grant Subscriber

    Messages:
    18,123
    Joined:
    Aug 2, 2004
    Location:
    West Midland
    Shooter:
    Multi Format
    It's not a critical formula and it's the sulphite that's important, the Bisulpite's almost irrelevat.

    I make fresh Hypom clear up every time I use it. but it'll last a few weeks or months. You could just split the packets and worry about the sulphite you need a 1-2% solution for actual use.

    Welcome to APUG BTW :D

    Ian
     
  3. fotch

    fotch Member

    Messages:
    4,813
    Joined:
    Mar 16, 2005
    Location:
    SE WI- USA
    Shooter:
    Multi Format
    Hello Elena and welcome to APUG. I am interested in the answers to your question also.
     
  4. clayne

    clayne Member

    Messages:
    2,805
    Joined:
    Sep 4, 2008
    Location:
    San Francisc
    Shooter:
    Multi Format
    You're way way better off buying a 5lb container of sodium sulfite and mixing up as you need it. The bisulphite is just a preservative for the HCA once it's in liquid form. If you just avoid that and mix as you need it you don't need a preservative and it only costs you 2 minutes to mix 100g with 1000ml of water. Dump after use.
     
  5. Gerald C Koch

    Gerald C Koch Member

    Messages:
    6,462
    Joined:
    Jul 12, 2010
    Location:
    Southern USA
    Shooter:
    Multi Format
    The purpose of the bisulfite is to lower the pH of the HCA to reduce swelling of the emulsion.
     
  6. ic-racer

    ic-racer Member

    Messages:
    7,513
    Joined:
    Feb 25, 2007
    Location:
    Midwest USA
    Shooter:
    Multi Format
    One advantage to Permawash. It is a liquid concentrate (probably cost more, however).
     
  7. nworth

    nworth Subscriber

    Messages:
    2,199
    Joined:
    Aug 27, 2005
    Location:
    Los Alamos,
    Shooter:
    Multi Format
    HCA is a pretty non-critical mixture of chemicals. In general, you can't mix up partial amounts of a powder formula. But in the case of HCA, you can generally get away with it. Look for the net weight on the container, and proportion accordingly. If the powder in the box hasn't started to clump up, it will probably work.

    More generally, try 1 teaspoon of sodium metabisulfite and 4 teaspoons of sodium sulfite per liter of working solution. That formula does not have any of the stain preventing and chelating agents that HCA has, but it works to reduce wash time.