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  1. #131
    David A. Goldfarb's Avatar
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    Thanks. I don't think they had it when I was working on monobaths.

    What does it do in MM1? I couldn't find an explanation in a quick skim.
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  2. #132
    keithwms's Avatar
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    Offhand I don't know, let me look in Haist and see. Obviously it adds viscosity, and perhaps therefore has some preserving effect (preventing oxidation of pheni?).
    "Only dead fish follow the stream"

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  3. #133
    Photo Engineer's Avatar
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    Glutaraldehyde is not known to increase viscosity, therefore something else is going on. GA is a hardener used in prehardening baths. It reacts in a manner similar to formalin and glyoxal. The fumes are quite toxic. Take care.

    PE

  4. #134

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    Glutaraldehyde is definitely intended to function in MM1 as a hardener. If I recall correctly, at the time he was formulating MM1, Haist found that films were less hard than they used to be. Perhaps with only 4g sodium hydroxide/litre, emulsion softening with modern films might not be such a problem, and you could get away with omitting it. Avoid the nasties when you don't need them!

    Glyoxal is supposedly slightly less toxic than formalin, but the danger then might be instead of treating it with the respect it deserves, you could be lulled into a false sense of security by the slightly less pungent fumes.

    Philip Jackson

  5. #135

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    A cysteine monobath

    Haist’s Monobath Manual doesn’t include any discussion of cysteine fixation, however there is an interesting patent (4,205,124 / 1980) by Harvey A. Hodes, who seems to have been working for the US Air Force (probably alongside Marilyn Levy, of POTA fame, at Fort Monmouth, NJ). Hodes formulated a low gamma developer consisting of:

    Phenidone – 1 gram
    Hydroquinone - 2 grams
    Sodium carbonate - 10 grams
    Sodium sulfite - 30 grams
    pH 10.2 to 10.4

    Hodes claims this formulation is oxidatively stable, even in a Versamat processor, after five days exposure to air, or after storage for 16 hours at 160F. He also formulated two monobath variations. The first, designated A, has an additional 50 grams of sodium thiosulfate and 4 grams of polyetheleyne oxide, which functions primarily as a development accelerator and secondarily as a protective colloid to preferentially attract sludge. Hodes’ B monobath formulation uses 10 grams of cysteine hydrochloride instead of thiosulfate; the quantity of sodium carbonate is also increased to overcome the acidity of the cysteine hydrochloride:

    Phenidone – 1 gram
    Hydroquinone - 2 grams
    Sodium carbonate - 40 grams
    Sodium sulfite - 30 grams
    Cysteine hydrochloride – 10 grams

    I haven't tried this but it sounds interesting. Cysteine should be innocuous compared to some of the other similar sulphur related fixing compounds (perhaps a benefit compared to the mercaptoacetic acid formula mentioned by David Goldfarb at #128 above?).

    Philip Jackson

  6. #136
    David A. Goldfarb's Avatar
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    Thanks for adding another one to the list.

    So if one wants to try some of these formulas that use chemicals that aren't normally stocked at places like the Formulary and Artcraft, how does a civilian go about ordering from Sigma-Aldrich or one of the big suppliers? When I've looked, it's seemed like they are more oriented toward larger orders for commercial labs or schools that use purchase orders, have accounts, and such.
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  7. #137
    Photo Engineer's Avatar
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    Be careful with Cysteine HCl. There are reports that it can cause reticulation!

    The Formulary has Cysteine HCl. I have found that they have a lot of chemicals that are not on their list. Just call and ask Sherry!

    PE

  8. #138
    Ian Grant's Avatar
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    Quote Originally Posted by David A. Goldfarb View Post
    So if one wants to try some of these formulas that use chemicals that aren't normally stocked at places like the Formulary and Artcraft, how does a civilian go about ordering from Sigma-Aldrich or one of the big suppliers? When I've looked, it's seemed like they are more oriented toward larger orders for commercial labs or schools that use purchase orders, have accounts, and such.
    Any good supplier should be able to get the chemicals from Sigma-Aldrich for you, my suppliers in the UK could get me obscure chemicals from a variety of other companies.

    But it's not the volumes that are usually the issue rather that various agencies require that chemical companies sell via official purchase orders to companies, often wanting to know what the chemicals are to be used for. Surprisingly it was the police that asked my supplier not to sell direct to the public, about 10 years ago..

    For some reason they don't bother with suppliers like the Formulary, Artcraft etc selling to the public, and in other fields you can walk into a jewellery suppliers (in the UK) and buy 5kg of Potassium Cyanide (used for cleaning castings) with no paper work, & just pay cash.

    Ian
    Last edited by Ian Grant; 02-04-2010 at 12:49 AM. Click to view previous post history.

  9. #139

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    I found some cysteine hydrochloride at a health food store. It wasn't cheap - $25 Australian for 100g - but factoring in shipping, may be cheaper than Sigma Aldrich or Photographers Formulary, at least for a small quantity, and presuming the quality isn't significantly different. Apparently it's sold as a dietary supplement, though I'm not endorsing it for any non-photographic purpose!

    As an aside, since cysteine is sometimes made commercially from human hair, there are suggestions of cannibalism in its consumption, though I can't see why swallowing a hair on a piece of lettuce should make you a carnivore, much less a cannibal. -Philip

  10. #140

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    Summer Cannibals... but some are not.

    Quote Originally Posted by Philip Jackson View Post
    I can't see why swallowing a hair on a piece of lettuce should make you a carnivore, much less a cannibal. -Philip
    Even Vegetarians love those Bedroom Carnivores!

    ...
    The cauldron was a-bubbling
    the flesh was lean
    and the women moved forward
    like piranhas in a stream
    they spread themselves before me
    an offering so sweet
    and they beckoned and they beckoned
    come on darling eat
    ...
    They circled around me
    natives in a ring
    and I saw their souls a-withering
    like snakes in chains
    and they wrapped themselves around me
    ummm what a treat
    and they rattled their tales hissin'
    come on let's eat !

    From Patti Smith "Summer Cannibals"



 

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