From: Bob Kiss (bobkiss@caribsurf.com)
Date: 04/10/00-03:14:38 PM Z
DEAR SIL,
Thanks for the info but if you read my e-mail carefully it explains that
I have indeed sourced EDTA Tetra sodium here. Though I didn't mention it I
did indeed source it from a detergent manufacturer. Please also note that
there is also EDTA Di sodium so not all EDTA is the same. Further, please
read Jeffrey Mathias' research report carefully where he states that the
EDTA that he is using is NOT EDTA Tetra sodium. Hence my question
stands..where to get the re-agent he is referring to...hopefully from a
supplier near NYC.
CHEERS!
BOB KISS
-----Original Message-----
From: Sil Horwitz <silh@earthlink.net>
To: alt-photo-process-l@skyway.usask.ca
<alt-photo-process-l@skyway.usask.ca>
Date: Monday, April 10, 2000 2:35 PM
Subject: Re: SOURCE?
>At 2000/04/09 11:45 PM -0400, you wrote:
>>Bob Kiss wrote:
>> > I had a difficult time finding EDTA Tetra sodium here in Barbados, let
>> > alone trying to find the EDTA you are speaking about.
>> > ... Where can I get
>> > some... .... Is there somewhere with an e-mail address who
>> > could ship it to me? Or at least a fax #? ...
>>
>>The EDTA I used to mix with the sensitizer, I got from Vicente-M. Vizcay
>>Castro mapa@ctv.es
>>
>>The EDTA(Na4) I used as a clearing agent, I got from John Melanson
>>melanson@audiologic.cirrus.com
>
>EDTA(Na4) is EDTA tetra sodium - very common substance, used in almost all
>consumer laundry and washing products! If you have a commercial chemical or
>industrial chemical source in Barbados (or certainly on one of the larger
>islands) they should have the commercial grade, which is good enough for
>photography. Its only purpose in life is as a sequestering agent - that is,
>it can prevent two normally interactive ions from joining. In wash agents,
>it is used to prevent the calcium and other metals from forming insoluble
>salts with residual fixer. If you need to know proprietary names, the most
>common one is "Sequestrene", but it is also commercialy known as Versene,
>Tetrine, Trilon B, Calsol - try some of those on the laundry places: they
>may actually be able to supply it. It is also a chelating agent (if I
>recall my classic languages, the "chel" part means "claw") to form very
>complex compounds of salts that normally react adversely. The most common
>in photography is Ferric EDTA, used in color bleach-fix solutions in
>conjunction with hypo (and ferric thiosulfate is insoluble, so you couldn't
>dissolve hypo in an iron solution normally); the iron part reacts with
>silver to form a salt, which the hypo then promptly dissolves. Ingenious!
>(Hey - this is from the top of my head, and it's difficult to dig in there
>in all the unused information!)
>
>I've often wondered if ferric EDTA could be used as the iron ingredient in
>alt photography, but have never had the time to research the field and do
>the experimentation. Perhaps someone on the list has tried this?
>
><<sil>>
><silh@psa-photo.org>
><webmaster@psa-photo.org>
>Sil Horwitz, FPSA
>Technical Editor, PSA Journal
>check out <http://www.psa-photo.org>
>personal page: http://home.earthlink.net/~silh/
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