[alt-photo] Re: dilution of pt/pd - FO and Ox

[EJ Photo]

I believe you'll also find that what appears to be an excessive amount of
oxalic acid can help keep you FO useable longer as it helps prevent the
formation of ferrous in your ferric. Ferrous is what you what UNDER the
light, but not before.

Eric 

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
 

-----Original Message-----
From: alt-photo-process-list-bounces at lists.altphotolist.org
[mailto:alt-photo-process-list-bounces at lists.altphotolist.org] On Behalf Of
Clay Harmon Website
Sent: Saturday, July 24, 2010 6:34 AM
To: The alternative photographic processes mailing list
Subject: [alt-photo] Re: dilution of pt/pd

Mark, adding oxalic acid to the FO will shorten the exposure time. I tested
this years ago, and it is increases the light sensitivity of the coating
solution. And slightly increases its exposure scale. And makes it easier to
clear. No downside to adding it that I was ever able to detect. My formula
is 27g FO, 4g oxalic acid, 2g EDTA to make 100ml. I think this is a pretty
standard mix.

clay
> 
> I would be interested (like David) in hearing comments about adding oxalic
acid to FO and the purpose for doing so-to make it dissolve easier?  Does
the FO from B&S have oxalic acid added to it?
> 

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