U of S | Mailing List Archive | alt-photo-process-l | RE: ferric oxalate

RE: ferric oxalate

13 Kasım 2008, Perşembe, 12:25 am tarihinde, Judy Seigel yazmış:
> ... for instance, threw out a large hunk of ferric ammonium
> citrate because it had turned into just that -- a really hard, solid hunk.
> It could have been 5 years old, but was well packaged (tightly wrapped in
> supposedly air and water tight plastic)... Anyway, I was suprised...

Surprising indeed! I have 5 y/o FAC which is perfectly fine (I still use
it for mixing Cyanotype solution A), still looks the same and works the
same when I first opened the container... The only reason I can think of
is; somehow, the container wasn't airtight so it got moisture in the air
(it's a quite hygroscopic material). Maybe you could crush it in a mortar
and microwave it to get rid of water. On the other hand, it's relatively
cheap to justify such a PIA...