From: Eric Neilsen (e.neilsen@worldnet.att.net)
Date: 02/05/02-10:06:40 PM Z
Sandy, There are two DIFFERENT compounds. The is NOT AN ERROR. I use
Ferrous Ammonium Sulphate CAS# 7783-85-9. Ferric Ammonium Sulphate CAS #
7783-83-7 is NOT what I use. This is referenced in Dick Stevens' Making
Kallitypes - A definitive Guide pgs 53-55. While there are other formula
for making ferric oxalate that do use ferric ammonium sulphate ( see pg 50 )
the one listed on my web site does NOT.
Perhaps this is why Jeff B you should look at learning to make your own. AS
for what other reasons....
Jeffrey mentioned some very important points. You can certainly make high
quality liquid or powder if you are the kind to roll up your sleeves a
little.
Sandy, I 'd be happy to share with you the formula that does require FERRIC
AMMONIUM sulphate. I found it to be a little more work.
I have also made the "exotic" ferrics listed in TNPP. There was also
mention of "exotic" ferric in text the was shared with me at a workshop from
a EJ Walls photo book.
Eric Neilsen
Eric Neilsen Photography
4101 Commerce Street, Suite 9
Dallas , TX 75226
214-827-8301
Web Sites : www.ericneilsenphotography.com
http://e.neilsen.home.att.net
----- Original Message -----
From: "Richard Sullivan" <richsul@earthlink.net>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Tuesday, February 05, 2002 1:20 PM
Subject: Re: Ferric Oxalate
> At 09:51 AM 2/5/2002 -0500, you wrote:
>
>
>
> >Eric Neilsen wrote:
> >
> >
> >>
> >>I have a how to section on my att web site for Ferric Oxalate. This is
for
> >>a direct to liquid approach. I has been discussed that this method my
have
> >>impurities in it. Perhaps, but if you make it carefully and repeat how
you
> >>make it, the variations from batch to batch are not a problem. As for
how
> >>difficult? expensive? The first time you make it is certainly a new
> >>experience and getting small quantities of supplies may be more costly,
but
> >>slightly increasing the supplies pays off in the long run.
> >
> >
> >At your site you note that the chemicals required are 1) Ferrous
Ammonium
> >Sulfate ( Ammonium Iron II Sulfate), 2) Hydrogen Peroxide 30 - 50%,
> >3) Oxalic Acid (Dihydrate), and 4) Potassium Ferricyanide.
> >
> >I have some Ferric Ammonium Sulfate. Would this be the same as Ferrous
> >Ammonium Sulfate?
> >
> >Sandy King
>
>
> Sandy,
>
>
> The "ferrous ammonium sulfate" is in error. As the old Arkansas farmer
once
> said, "You can't get there from here."
>
> It is "ferric ammonium sulfate." In this case a harmless error however it
> is an error that could cost lots of time, energy and some money.
>
> You can make the "exotic ferric oxalates" lithium ferric oxalate, sodium
> ferric oxalate and ammonium ferric oxalate with the powder version but
I've
> not been too successful making it from liquid. It is difficult to get all
> of the sulfates and ammonia out of the hydrate.
>
> The exact formulas for the exotics are in the Sullivan and Weese book but
> it can be done quite accurately by titration:
>
> Make a standard FO solution.
>
> Add the carbonate (lithium, sodium, or ammonium (ammonium hydroxide will
do
> as well) until no more precipitate is formed. When the alkali is added it
> will turn the solution yukky. (see the Chemical Dictionary for exact
> definition of yukky)
>
> Slowly add oxalic acid until the color shifts back from yukky to a pretty
> green.
>
> Stop when the color shift stops.
>
> Voila: sodium ferric oxalate, ammonium ferric oxalate, or lithium ferric
> oxalate.
>
> Haven't ever tried cesium. Go for it.
>
> --Dick Sullivan
>
>
>
>
>
>
> >--
>
>
>
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