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

VDB nasty staining problem


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 drake photography