Guys, it's not the wash; give that one up already or do the diffusion-rate calculations and go argue in a washing thread. This is RC and not FB, you don't need to drown it for two hours and residual-hypo testing shows that my prints are sufficiently washed or maybe even over-washed. PE: I'm not talking about film; that gets a 10+ minute wash with about 20 changes (much more than the Ilford method suggests), and the water comes out completely clear by about halfway through. My film bases are completely clear, no trace of pink/purple/etc in Acros/TMY. Believe me, I can wash stuff.
As to "why Jobo?", it's space constraints. I can process 20x24" in it no worries but couldn't even put down two trays of that size. If I'm making lots of 8x10", I can process 6 at a time in it. It's not inefficient or ineffective, it uses less chemistry and it means I can work in my laundry with just a 650x2500mm bench that holds sink, Jobo and enlarger. And I can process C41+RA4 with good process control and no dying of fumes or amine sensitisation.
It's not contamination from the back of the print behind because the top print on each pile was often the worst affected. If it were fixer contamination from when the prints were originally processed, why did they keep absolutely perfectly for 5-6 years in the very same piles before I added any Sistan?
There are no ozone sources in the building, not even a CRT. Again, no degradation on prints stored in boxes for 5+ years without Sistan.
I'm buying a squeegee for my RC, re-printing a bunch of stuff on FB and calling it a day I think.
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I am sorry to say but to me everythings points to unintentional operator error caused by not completely following the instructions provided by Adox/Agfa. Also did the frames you used have a wood fibre backs if so this can cause stains as well....
That's horrible!
I don't think AgSTAB is in market anymore. Last time I looked, it wasn't sold by anyone, at least in US. If that is the case, I don't think the manufacture will even care to troubleshoot.
If you store prints in the dark (no radicals formed) or don't put glass in front of them (radicals outgas with little/no damage), or use probably any paper other than Foma (Ilford and Kodak at least included agents to neutralize the radicals), it doesn't happen.
The cause is UV on the TiO2 brighteners releasing oxygen radicals, which affect the silver image (freeing silver ions which can then migrate to the surface) if it is held in a sealed frame.
Actually, Ctein's testing confirmed that proper washing without subsequent treatment will assure bronzing and silvering out.If you read the article by Ctein, you will find that proper washing will prevent bronzing when RC is used...
Washing in the Jobo tube with a brief rinse afterward doesn't sound like a good idea to me, even with RC prints. When I was processing color in rotary drums with some regularity (C-prints and Cibachrome), I would still wash with running water in a tray.
I'd had problems with a couple of Foma RC prints (there was a url link here which no longer exists) when framed, and Sistan was recommended as a good preventative measure. So I bought a bottle, made up a batch and processed basically my whole back-archives of B&W RC prints, including from other paper vendor
Bronzing of early RC papers has been well researched. It appears when prints are mounted under glass. There is a reaction between moisture, UV radiation and titanium dioxide which results in an attack on the plastic substrate. This causes yellowing and cracking. Blaming Sistan for this is a classic post hoc ergo propter hic logical fallacy. Newer papers were reformulated to prevent this from happening. It also brings up another matter. When mounting prints under glass the mount should allow the paper to "breath." Prints may outgas for years and the chemical products should not be allowed to accumulate.
I'd had problems with a couple of Foma RC prints (there was a url link here which no longer exists) when framed, and Sistan was recommended as a good preventative measure. So I bought a bottle, made up a batch and processed basically my whole back-archives of B&W RC prints, including from other paper vendors.
Well, that was a Really Stupid thing to do, because it has destroyed over half of my prints with serious bleaching in disgusting dribbly patterns that formed over about 8 weeks in dark storage. I'm talking about the loss of hundreds of dollars of paper and hundreds of hours of darkroom work here - prints that were in perfect condition are now good only for the bin - and I am extremely angry about it. I'll post some scans tomorrow, but believe me, the damage varies from "a spot" to "catastrophic"; it seems to be increasing and I suspect that I am going to lose all of my RC B&W prints. About 6 years worth!
Consider yourself warned in the most dire fashion possible.
but a long-term stability test didn't show any benefit either
If a stability test didn't show any change over 20 years then isn't that a good thing or were you expecting some kind of improvement? :confused:
I was expecting a difference between using it or not but there was none.Aslong as a print is mildly toned it is ok for decades!
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