RE: AHA!!! WAS Trivia time: room temperature solubility of platinic acid

Bob, I don't use Na2 from B&S so I can't absolutely give you an answer.
However, since Platinic Acid has the same chemical make up with the
exception of Hydrogen in place of Sodium, I can tell you that it affects the
contrast of prints made in my darkroom. And I regularly use more than just
one drop of platinum in my prints.

Did you try it? Or was the cost of Na2 contrasting agent holding you back?
Something else?

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

> -----Original Message-----
> From: BOB KISS [mailto:bobkiss@caribsurf.com]
> Sent: Friday, December 09, 2005 8:35 AM
> To: alt-photo-process-l@sask.usask.ca
> Subject: AHA!!! WAS Trivia time: room temperature solubility of platinic
> acid
>
> DEAR LIST,
> Finally an answer to the question I asked last year!!! I asked
> the
> list if I could use Na2 as a contrast control agent when using a mix of
> PT/PD in DOP prints. I mentioned that I used about 4 Pd to 1 Pt ratio. I
> don't recall getting a definitive answer but the gist was that it should
> work and that I should try it. Below Clay states that if there is any Pt
> in
> the mix it won't work. Sooooooooooooo... CHEERS! BOB
>
> Please check my website: http://www.bobkiss.com/
>
> -----Original Message-----
> From: Clay [mailto:wcharmon@wt.net]
> Sent: Friday, December 09, 2005 10:12 AM
> To: alt-photo-process-l@sask.usask.ca
> Subject: Re: Trivia time: room temperature solubility of platinic acid
>
> The problem is that using Na2 as a contrast agent only works with
> pure palladium prints. Any platinum in the mix and the Na2 reverts
> from the +4 oxidation state to the +2 oxidation state.
>
> Yes, it will still cool the tone in a lithium palladium print.
>
>
>
>
>
> On Dec 9, 2005, at 7:57 AM, Eric Neilsen wrote:
>
> > Maybe in my brevity I should have included a platinum (oops
> > palladium) terms
> > like the recent Gum thread. When I used Na, it meant Sodium the
> > element;
> > when I used Na2 that was in reference to the contrast agent. Those
> > would
> > have two different impacts on a print.
> >
> > Na2 can also be part of the chemical expression for the palladium
> > salt,
> > Na2[PdCl4]. That is not how Na2 was being used here.
> >
> > Clay, have you see your mixed prints, platinum and palladium,
> > showing the
> > same quick cool down? Or only those where the only metal salt was
> > Na2[PdcCl4]? And have any of you, seen a significant cooling of a
> > print made
> > with NH4 as your base for the palladium solution? Or for lithium?
> >
> >
> > I agree with everyone about Na2 - it takes only a small
> >> amount to
> >> significantly cool down a palladium print, ceteris paribus
> >
> > I haven't seen it with my ammonium palladium prints. It may be that
> > with all
> > palladium prints made with sodium based palladium only, that ceteris
> > paribus, applies. I would also add that before one can start
> > attributing
> > too many characteristics to a particular part of a palladium print,
> > all
> > components need to be listed and accounted for. The ferric oxalate
> > will play
> > a roll in the color of your print. The full interaction of all the
> > components have not been tested by me recently, but about 6 years ago,
> > sutble differences in color could be achieved by using a ferric
> > oxalate from
> > B&S, The Formulary, Artcraft or my homemade brew.
> >
> > The color shift may in part be due to interactions not based on
> > sodium but
> > pH changes. We all wait your test.
> >
> >
> > Eric Neilsen Photography
> > 4101 Commerce Street, Suite 9
> > Dallas, TX 75226
> > 214-827-8301
> > http://ericneilsenphotography.com
> >> -----Original Message-----
> >> From: Clay [mailto:wcharmon@wt.net]
> >> Sent: Friday, December 09, 2005 5:33 AM
> >> To: alt-photo-process-l@sask.usask.ca
> >> Subject: Re: Trivia time: room temperature solubility of
> >> platinic acid
> >>
> >> I'll let you know. The stuff is still in a small plastic bag in
> >> the
> >> form of crystals. So experimentation is forthcoming.
> >>
> >> I agree with everyone about Na2 - it takes only a small
> >> amount to
> >> significantly cool down a palladium print, ceteris paribus.
> >>
> >> Clay
> >> On Dec 8, 2005, at 11:46 PM, Eric Neilsen wrote:
> >>
> >>> Well, Yes. Perhaps my point missed both you and Sandy. Does
> >> the Na2
> >>> produce
> >>> prints of warmer color than prints made using Platinic Acid,
> >> where
> >>> the Na is
> >>> replaced in the compound by H. Discounting the effect that PT
> >> would
> >>> have on
> >>> the image tone by cooling it down a bit, and since the same
> >> amount of
> >>> platinum is in both the magical Na2 and in Platinic Acid,
> >> what then
> >>> accounts
> >>> for any difference in image color?
> >>>
> >>> So Clay, have you used both? What say ye?
> >>>
> >>> 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: Thursday, December 08, 2005 5:52 PM
> >>>> To: alt-photo-process-l@sask.usask.ca
> >>>> Subject: Re: Trivia time: room temperature solubility of
> >> platinic
> >>>> acid
> >>>>
> >>>> On Thu, 08 Dec 2005 17:18:43 -0600, Eric Neilsen
> >>>> <e.neilsen@worldnet.att.net> wrote:
> >>>>
> >>>>> In fact I can see no reason why it wouldn't
> >>>>> work as well or better than Na2. Better? More neutral. Na
> >> has a
> >>>>> tendency
> >>>>> to warm up palladium prints, so I'd expect the elimination
> >> of it to
> >>>>> reduce the warmth of your print.
> >>>>
> >>>> Hmmm... no. Na2 causes Pd prints to shift towards neutral.
> >>>>
> >>>> Kerik Kouklis
> >>>> www.kerik.com
> >>>
> >
Received on Fri Dec 9 08:59:19 2005