RE: Pt./Pd. question acid pre-soak

Sandy, Are you aware if any one test the AFO solutions in a similar way?

Eric Neilsen Photography
4101 Commerce Street
Suite 9
Dallas, TX 75226
http://e.neilsen.home.att.net
http://ericneilsenphotography.com
 

> -----Original Message-----
> From: Sandy King [mailto:sanking@clemson.edu]
> Sent: Thursday, August 11, 2005 12:19 PM
> To: alt-photo-process-l@sask.usask.ca
> Subject: RE: Pt./Pd. question acid pre-soak
>
> Eric,
>
> I ran the same tests, i.e. adding extra oxalic acid to the ferric
> oxalate. I don't remember exactly how much I added but I did test
> the pH with varying amounts added, and although the pH of oxalate
> solution changed from 6.5 down to below 5.8 I did not observe any
> increase in Dmax.
>
> Sandy
>
>
>
>
>
>
> >Kerik, How much "extra" oxalic acid did you try adding to the ferric when
> >you ran those test? And were you able to check the pH of the solution
> after
> >adding it?
> >
> >Eric Neilsen Photography
> >4101 Commerce Street
> >Suite 9
> >Dallas, TX 75226
> >http://e.neilsen.home.att.net
> >http://ericneilsenphotography.com
> >
> >> -----Original Message-----
> >> From: Kerik [mailto:kerik@kerik.com]
> >> Sent: Tuesday, August 09, 2005 11:17 AM
> >> To: alt-photo-process-l@sask.usask.ca
> >> Subject: Re: Pt./Pd. question acid pre-soak
> >>
> >> With certain (apparently) highly buffered papers like Fabriano
> Artistico
> >> Extra White, it is absolutely true. And just adding oxalic to the
> ferric
> >> didn't have the same effect. Other papers that aren't as buffered will
> >> show little or no change after being soaked in oxalic acid.
> >>
> >> Kerik
> >>
> >>
> >> >> I ran test when this was talked about years ago and found little to
> >> >> support it. I did not run test on a large sample of papers. I also
> >> >> queried those that made the claim to see if they could also just
> add
> >> >> some oxalic acid to their ferric and achieve the same increase in
> dmax.
> >> >> I got no response.
> >> >>
> >> >> Or is it simply a pH issue? Years ago Martin Axxon had suggested to
> me
> >> >> that he felt a lower pH paper gave a better print with PT solution.
Received on Thu Aug 11 12:14:58 2005