U of S | Mailing List Archive | alt-photo-process-l | Re: VDB nasty staining problem

Re: VDB nasty staining problem

hi loris

I do have some Na4EDTA and will give that a try. 
The staining I am getting is pale yellowish brown. The stain is also found only where the paper has been sensitized. If the stain was from the gold toner wouldn't the stain be throughout the entire sheet? However, it makes sense that the stain may be caused, as you say, by exposure to UV. the stain only appears after the print has been placed in the archival washer which is in another room lit by some florescent lights pretty much directly overhead. The stain gets worse over time as the print is washing. I was thinking it might be from the lights as it didn't make sense otherwise, unless the tap water is slowly reacting with contaminates in the paper. 

thanks for your advise,
david
On 4-May-07, at 12:57 AM, Loris Medici wrote:

Hi again David,

One more suggestion that could make Stonehenge work for you:

Use a dessert spoon of Na4EDTA + a dessert spoon of Sodium Sulfite in
1lt water for the clear right after fix and then wash as usual and see
if the stain will appear again... I had staining problems with
Chrysotype (not New Chrysotype, just plain AFO + KAuCl4 - stain was
showing up later when the print was exposed to daylight and / or UV
light) and was able to get rid of it by Na4EDTA+Sulfite final clearing
bath. Perhaps gold salt is attached to paper and causes stain later when
it gets reduced... !? Who knows? Just try and see if that's the case for
you. (The stain I experienced was kinda magenta/purplish...)

Regards,
Loris.

-----Original Message-----
Sent: Thursday, May 03, 2007 9:53 PM
Subject: Re: VDB nasty staining problem


thanks Loris, Don & Sam for your suggestions. 

I did some more staining tests yesterday with Stonehenge warm white.
Even after washing the prints for 10 minutes between toner and fix,
there was still staining. I had also cleared for longer 4.5 minutes (I
usually do around 2.5 minutes) and longer first  wash. The staining was
much less severe but still noticeable. Then I  tried the Platine which
showed NO STAINING. happy happy joy joy!!

The Stonehenge just is not clearing properly and I guess the gold toner
is just enhancing the stain? For the time being, I'm going to go with
the Platine because it just looks so amazing with the series I'm working
on!! the dmax simply kicks butt!   But I will try later with the
Stonehenge again. I don't think that the problem is particular to the
batch of paper I bought because I'm getting the same problem with white
and warm white. I'm wondering if the issue has something either to do
with humidity . I have been coating in a small room with higher humidity
than with previous sessions (my meter says between 50-60%RH but who
knows how accurate it is). 
The Stonehenge paper seems to be absorbing much more sensitizer than the
Platine. Perhaps higher humidity just isn't as good for the Stonehenge
as it is for the Platine? Which leads to the more absorbant Stonehenge
not clearing as well? too many questions. 

Don, I will try using multiple citric acid baths in the future. It's a
great  idea but, also, alot of distilled water. especially with the big
prints I'm doing now which use around 3 litres per tray and one shot. 

david

david drake photography
www.daviddrakephotography.com