[alt-photo] Re: dilution of pt/pd - weak black from B&S

[Terry King]

Eric


She made the prints at home; the results really upset her.  I asked her to bring the prints and her  B & S ferric oxalate to the studio We made new prints using the method she had used with fully dissolved pure ferric oxalate and we saw what she meant. We then added oxalic acid  to her solution and she got beautiful prints. We did this in the dead time on another process during one day.


Terry





-----Original Message-----
From: EJ Photo <ejnphoto at sbcglobal.net>
To: 'The alternative photographic processes mailing list' <alt-photo-process-list at lists.altphotolist.org>
Sent: Sat, 24 Jul 2010 15:41
Subject: [alt-photo] Re: dilution of pt/pd - weak black from B&S


It may very well be that not enough time was given to the FO solution to get
completely dissolved, it may be that the addition of the acid, allowed for
it to complete the process. How soon after mixing did you try and use the
solution of FO?  

Eric Neilsen
Eric Neilsen Photography
4101 Commerce Street, Suite 9
Dallas, TX 75226
 
www.ericneilsenphotography.com
skype me with ejprinter
www.ericneilsenphotography.com/forum1
Let's Talk Photography
 



> I had one student who bought some pure ferric oxalate from B & S, good
stuff, nothing wrong with it, but it did not produce good platinum prints in
the same way as the ferric oxalate as we had made in class without using
molar solutions. The problem was solved by adding oxalic acid to the B & S
solutions. unsurprisingly,we deduced that the ph of the dilution had to be
more acid.  From other experience we also deduced that he it needed to be an
organic acid. Why should that be ? 
 

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