Ortho, Meta, and Tetra Borates

Discussion in 'Darkroom Developing and Printing' started by Dan Quinn, Oct 10, 2003.

  1. Dan Quinn

    Dan Quinn Guest

    A question by Lloyd Erlick prompted me to investigate the borates.

    Na2B4O7 + 2NaOH = 4NaBO2 + H2O and 4NaBO2 + 8NaOH = 4Na3BO3 + 4H2O
    tetra meta meta ortho

    Attached H2Os have been omitted. They are not needed to balance.

    The order tetra to ortho is in accord with the degree of hydration.
    The acids of boron add hydrogen and oxygen. In the above case sodium
    replaces hydrogen.

    Using borax, the decahydrate of the tetraborate, one may make the
    meta and the ortho forms as shown above. To make 100 grams of the
    tetrahydrate of the metaborate use 69 grams borax plus 14.5 grams
    lye.

    Why 100 grams from 69 grams: One deca vs four tetra hydrated
    molecules is part of it. The rest is the sodium and some of the
    oxygen from the sodium hydroxide.

    It's interesting to note the great capacity the meta has for
    additional NaOH. Additions of NaOH beyond that needed for the
    conversion to the meta form are not available. They are combined
    with the meta to form the ortho. Only after a complete coversion
    is there free NaOH in the solution.

    AFAIK, sodium orthoborate is not available. I do not know of it's
    solubility, or ph of it's solutions. If it is like it's acid, boric
    acid, it's solubility is low. Dan
     
    Dan Quinn, Oct 10, 2003
    #1
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  2. Dan Quinn

    Jorge Omar Guest

    Dan

    Slightly off topic:

    Do you know if plain granulated boric acid has heavy metals as
    impurities?
    The reason for the question is that I've tried, to improve keeping
    properties of an ascorbic acid dev, to split it in two solutions - one
    concentrated, with sulfite, phenidone, ascorbic acid and boric acid; the
    other with sulfite and carbonate.

    Well, it was the shortest lived dev I've ever mixed...
    Even lost some nice shots ))-:

    Thanks,

    Jorge

    (Dan Quinn) wrote in
     
    Jorge Omar, Oct 10, 2003
    #2
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  3. You are better off with just ascorbic acid and phenidone dissolved in hot
    glycerine or propylene glycol. You can make a 10% ascorbic acid solution
    with enough phenidone to catalyze all of it. Use 10 ml of this solution with
    10 ml of 15% sodium carbonate to make a liter of working solution and
    develop for 8 minutes at 70 F.

    When I say hot, I mean hot enough to boil water. It lasts because the glycol
    does not ionize the agents without water.
     
    Patrick Gainer, Oct 10, 2003
    #3
  4. Dan Quinn

    Jorge Omar Guest

    Patrick

    I've done just that.
    - Mixed Pglycol with phenidone as a 2% stock solution (and, as per one
    older suggestion of yours also a pinch of hydroquinone - same as I've done
    with alcohol). It solved quite well at 50 centigrades.
    - Mixed 20g of ascorbic in 200cc of Pglycol plus a pinch of hydroquinone.
    Maybe it wasn't hot enough, but it was a PIA to solve...
    - Prepared the concentrated by adding 25 cc of the phenidone solution to
    the ascorbic one, final volume to 250cc with Pglycol.
    - The other solution is 75g sulfite plus 12g borax in 500cc water. AFAIK
    sulfite helps ascorbic to do it's chore, so borax is enough as an alkali
    (for 125PX 6cc of P-A stock, 50cc of stock 2, water to 300cc; 10 min @20C
    agitation every 2 min). I still have to fine tune the time.

    I will let you know how long it keeps (but it will take some time), and
    will do a compare test without sulfite.

    But I'm still wondering why boric acid killed the developer so quickly (an
    much older botlle half filled with E-76 formula is still OK).

    Jorge
     
    Jorge Omar, Oct 10, 2003
    #4
  5. I'm not sure it was the boric acid. If the sulfite was enough to neutralize
    both the ascorbic and boric acids and bring the pH up a little more, you no
    longer have an acid pH and oxidation can proceed faster than if you just had
    phenidone and ascorbic acid in your stock. That's just a guess, of course.
     
    Patrick Gainer, Oct 11, 2003
    #5
  6. Dan Quinn

    Dan Quinn Guest

    IIRC, an off and on aim of Mr. Gainers is a sulfite free developer.
    I suggest this aproach: Part A, ascorbic + phenidone. As. acid is quite
    acid. Part B, whatever makes it work.
    From what little I've been able to find, sulfite will NOT act as a
    preservitive. In fact the Vi. C will preserve the sulfite. Perhaps
    others can confirm that. Keep the air away; small bottles,sealed
    All chemicals may carry impurities. Copper may be the worst. It
    in particular is mentioned as a catalyst for oxidation.
    FWIW, P. Dignan used sodium bisulfite, 5gr, and phenidone, 1gr,
    for a 1 liter stock solution.
     
    Dan Quinn, Oct 11, 2003
    #6
  7. Dan Quinn

    Jorge Omar Guest

    The pH of the phenidone/ascorbic/sulfite/boric solution was 6.5 (it took
    a lot of boric to do that - 100g/liter - yes, it did dissolve).
    I used carbonate (and more sulfite) as the alkali in the second solution,
    to rise working pH to 8.6.
    So I do not think pH was responsible, even more because E-76 is
    phenidone/ascorbic/sulfite/borax (one of the Xtol clones, pH 8.6 and is
    (was?) still working, even in a half filled bottle some 45 days after
    mixing, 1+2 one shot).
    I will test it from time to time (black leader) just to see how long it
    goes.

    The only 'new' ingredient was boric - that I had not seen used anywere
    with ascorbic. Maybe due to the huge quantity even a trace ammount of
    metal become objectable?

    In the same week I did a black leader test (ok), a test strip (ok), and
    two 15 real shots strips - and by the second it was gone...

    Jorge
     
    Jorge Omar, Oct 11, 2003
    #7
  8. Dan Quinn

    Jorge Omar Guest

    My aim was slightly different - to do a longer lasting Xtol clone - and,
    first test was a real faillure ))-:

    Now I'm testing Patrick Gainer's propylene glycol mix - but still using
    sulfite/borax in the second solution.

    Why this love for Xtol clones?

    - I've seen lots of posts by Xtol users that if it does not suffers
    sudden death, it's very good - and I can confirm that, using a clone.
    - I've seen bibliographical references that sulfite helps ascorbic acid's
    work;
    - I've seen postings that borax acts as a fine grain component (emulsion
    hardening)

    The fact is that Xtol and its clones are low pH, sulfite/borax based
    (and, when dilluted 1+2 or 1+3 are not high sulfite devs).

    See my last post to Patrick Gainer re the boric acid and the problems I
    had.

    A note: Mr. Dignan's reserve solution does not keeps; ascorbic/sulfite
    devs life can be compared to D-76.
    See:

    http://www.udmercy.edu/crna/agm/phenvitc.htm

    Mr. Gainer's phenidone in alcohol solution keeps well (I've mixed it more
    than once, 250cc at a time, since my paper dev is phenidone based) and
    used it to the last drop.

    Jorge

    (Dan Quinn) wrote in
     
    Jorge Omar, Oct 11, 2003
    #8
  9. Dan Quinn

    Dan Quinn Guest

    As long as you are doing longevity tests, you'll need to test Xtol
    itself. Mytol should be tested and others less heard of. Years of
    uninterupted diligence lie before you.
    BTW, that long paper on developer longevity showed that the complete
    single bath developers lasted longest. Xtol is one of those. Dan
     
    Dan Quinn, Oct 13, 2003
    #9
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