RE: Ferric Oxalate or Ferric Ammonium Oxalate
So you're saying that: if you lower the Fe concentration so that it is balanced to your KPt solution "which is close to saturation" (but not saturated), then there shouldn't be any problems - except max. density loss due to less strong sensitizer. Am I getting it right? My understanding of Mike's explanation was that AFO and K salts don't get well together because of formation of some unsoluble compound - which is not good if you want a rich and grainless image with smooth transitions. He wasn't complaining about having to use a less strong sensitizer at all. Well, I have to ask him -> maybe what he shared back then was completely unapplicable to Pt/Pd chemistry. (Remember, the context was Chrysotype -> gold in our correspondence.) Regards, Loris. -----Original Message----- From: Eric Neilsen [mailto:ejnphoto@sbcglobal.net] Sent: 07 Kasım 2006 Salı 09:02 To: alt-photo-process-l@usask.ca Subject: RE: Ferric Oxalate or Ferric Ammonium Oxalate Loris, I believe it is two fold. That ammonium platinum salt can get to a .7M solution just like the ammonium palladium concentration that he suggest along with a 1.4 M AFO so that your solution is balanced. Eric Neilsen Photography 4101 Commerce Street Suite 9 Dallas, TX 75226 http://e.neilsen.home.att.net http://ericneilsenphotography.com Skype ejprinter > -----Original Message----- > From: Loris Medici [mailto:mail@loris.medici.name] > Sent: Friday, November 03, 2006 4:16 PM > To: alt-photo-process-l@usask.ca > Subject: RE: Ferric Oxalate or Ferric Ammonium Oxalate > > Oops! Potassium Oxalate is soluble!!! > > I don't remember exactly but Mike told me that K metal salts and AFO > will cause formation of an insoluble salt which incorporates K and > Oxalate (and possibly something else)... In this correspondence, the > context was Chrysotype but I think this is applicable to Pt/Pd > printing also; since he doesn't use the ordinary K salts, he uses the > NH4 salts instead (this should hint some problems related with K > salts). > > Regards, > Loris. > > -----Original Message----- > From: Loris Medici [mailto:mail@loris.medici.name] > Sent: 04 Kasım 2006 Cumartesi 00:08 > To: 'alt-photo-process-l@usask.ca' > Subject: RE: Ferric Oxalate or Ferric Ammonium Oxalate > > ...My understanding is that Mike doesn't like K salts because it may > cause forming of Potassium Oxalate which is insoluble, therefore will > cause a gritty sensitizer...
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