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

Re: VDB nasty staining problem

Loris, thanks for your comments. I haven't received anything from anyone else. 
I have been using the toner one shot (as Sandy King recommends). I'm making large prints (14x20") which require aprox. 140 ml per print of toner. 
I do also use plain sodium thiosulphate as fixer. I'm assuming that when you say sodium thiosulphate 'toner' you meant that you didn't use toner?
The gold/thiourea toner I'm using includes some sodium chloride (5 gm/250 ml toner) which perhaps works to balance out the acidity? 
But you have a very good point. I will try washing for longer between toner and fixer. 
This is the toner formula that I am using:

Gold chloride (1% solution)- 12 ml
Thiourea (1% solution)- 12 ml
Tartaric acid (10% solution) - 12 ml
Sodium chloride - 5 gm
Distilled water to make 250 ml.

I am also going to try different paper today and other combinations to try and narrow down this rather upsetting development. 
thanks Loris, 
david


On 2-May-07, at 5:18 AM, Loris Medici wrote:


David, I don't know if you got offline replies to this but will comment
anyway:

Could it be that your toner is exhausted (and therefore acting in a
funny manner)? 8 minutes sound very long to me; it was usually taking
not more than 2-4 minutes (30 seconds with very fresh toner) to tone my
prints with gold/thiourea toner... When have you mixed it and how many
prints did you process with it? (This question applies only in the case
you're not using fresh toner for every print.)

One more speculation: I was using plain sodium thiosulfate toner with my
Vandykes (2% for 2 minutes - refreshing it every 3 prints). AFAIK
gold/thiourea toner is acidic, maybe the wash after toner is not long
enough to clear it completely so that it won't react (somehow!?) with
the alkaline fixer. Have you tried plain fixer?

Regards,
Loris.

-----Original Message-----
Sent: Monday, April 30, 2007 3:22 PM
Subject: VDB nasty staining problem


Hello


I'm having a bad staining problem with gold/thiourea toned VDB prints.
The staining appears during the final wash. It's fairly consistent
throughout the print (there are some lighter blotches) but clear around
the edges of the coated area. I'm thinking that the sensitizer is not
being cleared properly and there is some residual silver but I don't
understand why the stain only appears after the fix and in the final
wash?


I use a citric acid clearing bath for 3 minutes, then wash for a 3
minutes, then gold/thiourea toner (8 minutes), then wash, then alkaline
hypo for 4 minutes and then 1% sodium sulphite clearing (2 minutes),
then final wash (30 minutes). 
I have been using Stonehenge White paper. I also just started using a
Richeson 'magic' brush today, which was new today to my process (I have
previously been using a puddle pusher). 
At first I thought that the paper may have been not dry enough but
longer drying times after coating didn't help. I always air dry at least
20 minutes between and after the two coats. the coating and drying area
was between 50-60% RH.


I have been making palladium toned VDB's on Stonehenge paper for quite a
while and have never had this problem. I started with the gold toner in
the last month. 
Yesterday was quite a frustrating day! 


thanks for any advice.
david


david drake photography
www.daviddrakephotography.com

david drake photography
www.daviddrakephotography.com