Ammonia spell, where from?

[titrisol]

Either from rapid fixer or selenium toner.
Both have Ammonium Thio and either a strong alkali or chlorine make the Ammonia airborne

Nothing to worry about thogh, very good for colds and sinus

 

[Ryuji]

I've studied that IPI paper. It should be made clear that their
concern is with microfilm.

Here is your new trick for today. For complete protection
prepare a .01% solution of Na2S, sodium sulfide, then soak
the print in that solution. The IPI paper did not suggest
any times. I'd think 3 or 4 minutes would do.

If paper and microfilm silver are similar than the 1:9,999
solution will give very good archival protection.

IIRC, the matter of selenium's value as an archival treatment
is wholely concerned with microfilm. There may be no studies
of it's worth where papers are the subject. Dan

Microfilm and enlarging papers are fairly similar. There are differences but then I would say variations among enlarging papers is also large. If you are serious about archival concern, I would say you should consider all weakness found for microfilm as well as other silver material in order to enhance the permanence of your prints.

There are studies about enlarging papers, duplicating films, and other materials from various labs, including Eastman Kodak, RIT, national museum of Denmark, etc.

 

[Ryuji]

I wasn't clear enough. I don't mix the PermaWash and Selenium together directly, but add both of them to water to make my washing aid. I'm not adding enough selenium to act as a toner and change the print tone, but only enough to coat the silver particles and add permanence. When I want to actually tone prints, then, of course I keep them separate.

Larry

Protection from selenium toning is useful if the conversion is pretty complete. Even this is a vague statement and the actual benefit depends on a lot of variables. One study I know looked at the image degradation after oxidation treatment versus degree of conversion. The minimum conversion necessary to achieve a certain level of protection varied a lot depending on the emulsion. Even among pictorial material.
The problem is no one knows what physical/chemical parameter in the emulsion is correlated with this result, so one can't simply predict the permanence from speed, brand, etc, etc. On the other hand, polysulfide treatment is more consistent and sure-fire.

Another problem is that selenium toner left in the print is just as harmful as residual fixer. Prints must be washed thoroughly after coming to contact with toning agent.

 

[Ryuji]

All other things being equal, does treatment of negs and prints with KRST increase, have no effect on, or decrease archival permanence?

Given proper toning and washing, the permanence will be increased, but probably not as much as we would like, and not as much as what we could get from polysulfide toner.

 

[dancqu]

Microfilm and enlarging papers are fairly similar.
There are studies about enlarging papers, duplicating films,
and other materials from various labs, including Eastman
Kodak, RIT, national museum of Denmark, etc.

There are studies. Specifically, I've not seen one concerned
with selenium and FB paper. Never the less, nothing tops sulfide.

The IPI gives reasons for the use of polysulfide rather than
sodium sulfide. None of those reasons has anything to do with
sodium sulfide's effectiveness as an archival treatment. They
do not spell out their reasons for mentioning the polysulfide.
Drum quantities is likely a factor, manufacture, and S&H
are likely others.

They do say that sodium sulfide affords complete archival
protection at a 1:9,999 strength; 0.01%. in solution. Dan

 

[Ryuji]

The IPI gives reasons for the use of polysulfide rather than
sodium sulfide. None of those reasons has anything to do with
sodium sulfide's effectiveness as an archival treatment. They
do not spell out their reasons for mentioning the polysulfide.
Drum quantities is likely a factor, manufacture, and S&H
are likely others.

They do say that sodium sulfide affords complete archival
protection at a 1:9,999 strength; 0.01%. in solution. Dan

Various publications written by IPI people clearly describe why polysulfide is more preferred in practice. Plain sodium sulfide is good for lab testing as a comparison sample but it is very hard to use in practice because the solution is very unstable and has very small processing capacity. Strong polysulfide solution is a lot more robust, practical way to approach this problem in darkroom.

 

[dancqu]

Various publications written by IPI people ...
Plain sodium sulfide ... is very hard to use in practice
because the solution is very unstable ...

Very unstable! Gosh! You don't suppose it'll explode?

I'm not going to debate the sulfide vs polysulfide issue.
The reason; we are approaching the issue, each with our
own objective in mind for one or the others use.
I may or may not be interested in toning but I am
interested in LE.

Various publications; search Google for, stability black white .
At the very top, an Abbey Newsletter. Most central to this
debate is the section on sulfideing. Readers will have to
make up their own minds. I've read and now have a
couple of sulfide solutions being time tested. Dan

 

[Ryuji]

Various publications; search Google for, stability black white .
At the very top, an Abbey Newsletter. Most central to this
debate is the section on sulfideing. Readers will have to
make up their own minds. I've read and now have a
couple of sulfide solutions being time tested. Dan

Read that, and also key research reports mentioned in that paper.

Very dilute sodium sulfide solution is very unstable and does not keep.
Very dilute polysulfide is also a good agent for protecting prints
from oxidative attacks but has the same problem of very small processing capacity and short life. That is, polysulfide toner is also unstable if kept in dilute solution. This is one reason
IPI Silverlock is very concentrated.

There is an IPI Q&A section in RLG Preservation Handbook. If you don't believe me, that's probably the easiest source to get the same words from IPI. Their report to National Endowment for Humanities is also an essential reading. Unfortunately these good info are available on print only and not on the internet.