Re: Oxalic Acid Presoak for some pt/pd papers?

[Paul Viapiano <viapiano@pacbell.net>]

Hi Sam...

No, it never happened to me...(knocks on wood...)

I'm using 1% solutions in room temp water for 3 minutes.

Paul



----- Original Message ----- 
From: "sam wang" <stwang@clemson.edu>
To: <alt-photo-process-l@usask.ca>
Sent: Thursday, April 02, 2009 10:26 PM
Subject: Re: Oxalic Acid Presoak for some pt/pd papers?


> Paul,
>
> Have you or anyone else encountered the acid destroying the internal  
> sizing? It occurred to me a number of times, mostly on old stocks.
>
> Good way to make expensive but absorbent paper towels.
>
> Sam
>
> On Mar 27, 2009, at 7:34 PM, Paul Viapiano wrote:
>
> > Dan, I'm sure others will chime in but my findings are:
> >
> > 1. Fabriano EW, Arches Cover, Rives BFK, Stonehenge
> >
> > 2. Helps with better dMax, and general tonality, etc...so much of  
> > today's papers are so alkaline, heavily buffered, etc that the  
> > acidic pt/pd solution hits the alkaline paper and poor results occur.
> >
> > 3. 1 - 1.5% oxalic acid in water for 3-5 minutes...Stan Klimek also  
> > recommends this in the Arentz addendum. I dry flat on paper towels,  
> > but hanging is ok. I just don't want my corners marked with clips.
> >
> > 4. The Arentz book hasa whole chapter on paper; which ones are good  
> > to go as is, which need acidification, etc...
> >
> > Fabriano EW is my choice with excellent results. Platine is a great  
> > paper, but I've never produced the same or as good results as the  
> > Fabriano.
> >
> > After acidification, the single biggest tip is to humidify the  
> > dried, coated paper pre-exposure, and after you put the neg/paper  
> > sandwich in the frame, cover it with a piece of mylar the size of  
> > the frame before you put the back on and lock it up. Keeps the  
> > humidity in the paper during exposure and wow...! That made all the  
> > difference in my printing (also from Stan Klimek)...
> >
> > Hope this helps...
> >
> > Paul
> >
> >
> >
> > ----- Original Message ----- From: "Dan Burkholder" <fdanb@aol.com>
> > To: <alt-photo-process-l@usask.ca>
> > Sent: Friday, March 27, 2009 4:07 PM
> > Subject: Oxalic Acid Presoak for some pt/pd papers?
> >
> >
> > > Sorry if this has been beaten to death on the list already but a   
> > > Spanish friend wants the particulars of using a weak Oxalic acid   
> > > presoak for some of his pt/pd printing. He's running into some  
> > > monster- long exposure times as he prints on hand-coated inkjet  
> > > papers. He has  his reasons for doing this. Frankly, I'm impressed  
> > > he's getting the  results he is using a paper that isn't formulated  
> > > for any kind of wet  process. He hasn't checked the pH of the paper  
> > > and that seems like a  good place to start. In the mean time...
> > >
> > > Here are some questions to stir discussion:
> > >
> > > 1. What papers are noted to benefit from the acid presoak?
> > >
> > > 2. What problems (lower D-max, mottling, etc.) does the presoak  
> > > address?
> > >
> > > 3. What are the recommended acid dilutions and times and drying  
> > > procedures for this procedure?
> > >
> > > 4. And anything else that you think would help.
> > >
> > > I've never done the presoak thing but I am curious as to what  
> > > others  have to say about it.
> > >
> > > Thanks in advance for any help and suggestions.
> > >
> > > Dan
> > >
> > > info@DanBurkholder.com
> > > www.DanBurkholder.com