Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 69,761   Posts: 1,516,091   Online: 910
      
Page 2 of 2 FirstFirst 12
Results 11 to 20 of 20
  1. #11
    Thomas Bertilsson's Avatar
    Join Date
    Jan 2003
    Location
    Minnesota
    Shooter
    Multi Format
    Posts
    14,154
    Images
    288
    Quote Originally Posted by Rudeofus View Post
    You do realize that the Fototechnik Suvatlar link I posted above sits directly on Moersch's web page, yes?
    No, I didn't. If I did, perhaps I wouldn't have posted the suggestion, yes?

    I was just trying to help.
    "Often moments come looking for us". - Robert Frank

    "Make good art!" - Neil Gaiman

    "...the heart and mind are the true lens of the camera". - Yousuf Karsh

  2. #12

    Join Date
    Nov 2004
    Posts
    1,113
    Also note there are two forms of sodium metaborate, -4mol and Kodalk. Silverprint used to sell Kodalk.

  3. #13

    Join Date
    Jun 2012
    Location
    UK
    Shooter
    Multi Format
    Posts
    1,052
    Yes, as I said in my OP:

    Quote Originally Posted by pdeeh View Post
    Silverprint no longer carry it
    Regarding 4-mol and 8-mol, I have read posts here at APUG that suggest it is of no importance which is used for photographic work.

  4. #14

    Join Date
    Nov 2002
    Location
    Melbourne, Australia
    Shooter
    Medium Format
    Posts
    971
    Quote Originally Posted by pdeeh View Post
    Yes, as I said in my OP:



    Regarding 4-mol and 8-mol, I have read posts here at APUG that suggest it is of no importance which is used for photographic work.
    Which version you have will affect the amount needed, as one contains more water of crystallization.

  5. #15

    Join Date
    Nov 2004
    Posts
    1,113
    It's discussed here:
    http://www.apug.org/forums/forum37/1...ntrate-34.html
    It would be of interest to check with Moersch they sell Kodalk if you use this supply.

  6. #16

    Join Date
    May 2013
    Location
    US
    Shooter
    Large Format
    Posts
    2,060
    Wow, this is enlightening. Never had an inkling that sodium metaborate could be so confusing. It would seem the moral of the story is to always use Kodalk, and hope the publisher of whatever formula you're using had it in mind.

  7. #17
    paul_c5x4's Avatar
    Join Date
    Apr 2009
    Location
    Ye Olde England
    Shooter
    Large Format
    Posts
    1,399
    Images
    22
    Quote Originally Posted by pdeeh View Post
    Silverprint no longer carry it
    Oh bu***r. I had it on my list of stuff for the next order. Will have to try other sources...

  8. #18

    Join Date
    Jul 2010
    Location
    Southern USA
    Shooter
    Multi Format
    Posts
    3,769
    Sodium metaborate is not any different from any other chemicals. You must know the hydration form called for in the formula. Another example would be sodium carbonate -- anhydrous or monohydrate? Unfortunately many formulas are not written in a very accurate form.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  9. #19
    Rudeofus's Avatar
    Join Date
    Aug 2009
    Shooter
    Medium Format
    Posts
    1,533
    Images
    10
    Quote Originally Posted by Gerald C Koch View Post
    Sodium metaborate is not any different from any other chemicals. You must know the hydration form called for in the formula.
    The confusion comes from the fact that tetrahydrate can mean two different forms of hydration (NaBO2 * 4 H2O and Na2B2O4 * 4 H2O), something which is not an issue with most other compounds including Sodium Carbonate. The Xtol Concentrate thread referenced by Alan Johnson sheds some light on this.


    @Alan: Moersch does sell Sodium Metaborate through Fototechnik Suvatlar, see my previous post here in this thread.
    Trying to be the best of whatever I am, even if what I am is no good.

  10. #20

    Join Date
    Jul 2010
    Location
    Southern USA
    Shooter
    Multi Format
    Posts
    3,769
    There are 3 hydration forms of sodium metaborate' as evidenced by 3 CAS numbers

    Anhydrous (NaBO2) CAS 7775-19-1
    A dihydrate (NaBO2.2H2O or as Na2B2O4.4H2O ) CAS 16811-11-6
    A tetrahydrate (NaBO2.4H2O or as Na2B2O4 .8H2O) CAS 10555-76-7

    Things are made rather confusing by representing the anion in two different forms BO2- or as B2O4-2. Once the anion is represented the same way it is easy to see the different forms.

    The tetrahydrate converts to the dihydrate above 53.6C (128F).
    Last edited by Gerald C Koch; 09-27-2013 at 04:01 PM. Click to view previous post history.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

Page 2 of 2 FirstFirst 12


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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