Re: Ferric ammonium citrate
Dennis Klinker (DennisKlinker@denklik.demon.co.uk)
Sat, 22 Feb 1997 15:59:02 +0000
In message <3.0.1.32.19970218163108.0073afe4@roadrunner.com>, Richard
Sullivan <richsul@roadrunner.com> writes
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>I just had an interesting experience with ferric ammonium citrate. I don't know
>if anyone else has had this experience or not, and it may even be common
>knowledge, but I'll pass it along anyway.
>
>I just started working with Van Dyke Brown printing again after about 20 years.
>We're going to be selling kits and made up solutions, so I was experimenting
>with various formulas.
>
>I made a batch with my old favorite formula and got a heavy amount of yellow
>precipitate in the bottom of the beaker. So like a dumb dumb I filtered it off.
>(It's a movie called "Laurel and Hardy Do Photography") I made a print. Well I
>tried, and just got a faint image.
>
>This morning I tried another formula. Again, same yellow crud in the beaker.
>Hmmm.... I'm not throwing it away, this time. Put it in the old trusty Waring
>Blender, put on a Fred Waring CD (he invented the thing, you know) and whirred
>away. This time the crud just mixed in and made the solution cloudy. Well on to
>the next kitchen appliance, the microwave oven.
>
>Aha! No more cloudy solution, nice and clear. Well for a few minutes anyway. As
>it cooled down, the yellow cloudiness came back.
>
>Something was wrong. I made a ton of Van Dykes in the early 70's, and large ones
>at that. I never had any problem with mixing this stuff up. I figured it was
>either the materials were contaminated, or on the other hand, too pure. I was
>hoping not the first one. I paid good money for a drum of the ferric ammmonium
>citrate, and it had already made some nice Ware Cyanotype solution, so maybe it
>was too pure. If the old stuff worked, what could it have been that was in the
>ferric ammonium citrate that allowed the material to dissolve. Perhaps it was
>free citric acid. I put a little citric acid in a sample of the cloudy solution
>and it cleared almost immediately. Case closed.
>
>Moral of the story: if you are using a high quality grade of ferric ammonium
>citrate, add a little citric acid if the Van Dyke solution does not clear up.
>
>Dick Sullivan
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>Bostick & Sullivan
>PO Box 16639, Santa Fe
>NM 87506
>505-474-0890 FAX 505-474-2857
Hi Dick it was interesting to see your posting on the list regarding
FEC i work at a college in North London and recently we have had
problems with VDB giving problems of staining when the print is wet it
looks fine but as it dries the prints are covered with what looks like a
silver stain. This happens with all types of paper i have filtered the
chemistry but still the problem remains i have gone so far as to
pulverise the FEC in a mortar& Pestle to see if this could be the
problem but to no avail.The formula is the standard one in the Keepers
of Light and distiled water is used any ideas what the cause could
be.TIA dennisklinkerdenklik@demon.co.uk
--
Dennis Klinker