I have recently tried AGFA Viradon as a toner on my FB prints (AGFA and Forte FB papers). After toning and lengthy washing just about every single print ended up with eneven milky film over it. It looks like some sort of a sediment, residue etc. When the prints were wet I tried removing the film which was possible but not with great results, as well as it was likely to damage the paper's wet emulsion. This problem was never evident after sepia or selenium toning.
Is there a way of removing this milky film/sediment/residue from my prints?
Sounds like calcium carbonate precitipitation, did you use tap water or destilled water? Anyways, a mild citric acid bath might remove the white residue.
We had this problem with Hypo Alum toner which is great, however, as it gets older the prints end up with scum. Treat in a bath of 1 gallon of distilled water with 1 tablespoon of 28% acitic acid. Wash under running water, use cottong balls and wipe gently. Wash per usual. No problems. Would be worth a try.
Looking back through old posts, I found this.
If the scum doesn't go away with any of those methods, it could be sulphur. Just wipe it off with a soft brush or cloth while still in the water. This happens sometimes with polysulfide toners - and old hypo (as in Hypo-alum toners). Don't bother with the acid, it's not going to help.
Another possibility is Calcium Sulphate (=gypsum). In the amounts that are relevant here, it will readily dissolve in COLD water. It is a lot more difficult to dissolve it in hot water.
As you put more prints through your solution did it turn cloudy? I have found that once the cloudiness sets in it still tones OK but you get this greasy film on the prints. I have found a long soak in a hot solution of sodium carbonate and then a long wash in running water usually gets rid if the film.
But I have found a way for this not to happen and that is to use a highly dilute solution of Viradon, somehing like 1:50 or 1:75. Toning takes onger but it works.
try soaking the print in Sodium sulfite ("Hypo Clear") instead. That should dissolve the sulfur.
A highly dilute solution of Viradon might change the colour more than a more concentrated solution, so this is not always the best way.
I can now verify my own suggestion: Sodium Sulphite solution works - it really DOES remove sulphur from the surface of prints!