Adostab II for film

[Helge]

Adostab II (Sistan) is well established as toning agent for prints. But I use it as a wetting agent and light toner for film too as suggested by the sales pitch.
It’s absolutely superb as a wetting agent, and seems to give a nice tightness to the grain.

But:

A. Does anyone know of longterm or immediate harmful/negative effects? Read the horror story from a printer here. But it seems to be user error.

B. How many times can you use a 500 ml batch? I’ve used it about eight times, mainly because It didn’t lather up, and it seemed cheap to be on the safe side.
But judging by the print instructions, you should be able to use it many more times.
Any experience?

C. Edit forgot this one:
There is no clear explanation of how long it should work and with what agitation.
So I just did one minute with inversions.
Right?

 

[Andrew O'Neill]

I always thought Sistan was for increasing print longevity, especially RC papers. Ctein did a full on test with it in conjunction with KRST. How would it act as a toning agent??

 

[AgX]

Yes, the idea behind Sistan is not to tone at all, neither to be used as wetting agent, but to deposit scavengers for silver-ions that may come into existance under environmental influence.

 

[Helge]

Agfa Sistan was not a toner but a stabilizer (active ingredient potassium thiocyanate) with a wetting agent (surfactant) - the same surfactant as in Kodak Photo Flo. Agfa always cautioned not to exceed the recommended mixing concentration and to remove excess from the material being treated or else staining could occur with time.

Adostab II appears to be similar to Sistan. It contains the same stabilizer, and probably a different surfactant, so the same caution would apply regarding the mixing concentration.

Yeah it kind of is in the name.
Better long term stability was always my intention.
The rest is just gravy.
I just wanted to hear others a opinion on this little talked about product.
Here is the product description though:

• Adox Adostab is an image silver stabilizer for black and white materials. Uses the same active ingredients as Agfa Sistan, but in revised proportions to achieve improved archival performance. Protects films and paper from changes in the silver image and for archival protection without altering the image tone. Sistan protects films and paper from changes in the silver image caused by UV light and environmental effects. These faults initially appear as reddish to yellowish-brown highlight discolorations and the complete negative may be destroyed by the silver being converted to a colloidal form. Its causes are industrial and traffic fumes and fumes from heating oil, plastic paints, compressed boarding, cardboard with an acid content, glues, sticky tape, freshly cut PVC and brittle rubber and also ozone and all substances giving off peroxide.
  
  Adostab is recommended as an alternative to Selenium toner for fine art printers who want added archival protection without altering the image tone of the print. A slight increase in density may occur. Adostab can also be used alongside Selenium toner for additional protection.
  
  Apply Adostab like a wetting agent for 120 sec. There is no need to wash the print or film after use. Wipe dry and you're done.
  
  Dilute: 1+19 Capacity: 2 sqm per liter of working solution (=700 films per bottle or 40 sqm of prints).
  
  https://www.digitaltruth.com/products/product.php?brand=adox&link=adostab

 

[Helge]

Agfa Sistan was not a toner but a stabilizer (active ingredient potassium thiocyanate) with a wetting agent (surfactant) - the same surfactant as in Kodak Photo Flo. Agfa always cautioned not to exceed the recommended mixing concentration and to remove excess from the material being treated or else staining could occur with time.

Adostab II appears to be similar to Sistan. It contains the same stabilizer, and probably a different surfactant, so the same caution would apply regarding the mixing concentration.

I’m always careful not to exceed the amount of course. Just as with anything else development.

There is no clear explanation of how long it should work and with what agitation.
So I just did one minute with inversions.
Right?

 

[AgX]

There is no clear explanation of how long it should work and with what agitation.

It is not intented to work. Instead just a certain concentration within the emulsion is to be established by diffusion.
Such approach is not new, just think of the stop bath.

 

[Helge]

It is not intented to work. Instead just a certain concentration within the emulsion is to be established by diffusion.
Such approach is not new, just think of the stop bath.

Diffusion takes time.
And a certain concentration has to be present for it not to be homeopathic.
If/when the emulsion is saturated with water that helps a lot. But it’s still not instantaneous.

 

[RalphLambrecht]

Adostab II (Sistan) is well established as toning agent for prints. But I use it as a wetting agent and light toner for film too as suggested by the sales pitch.
It’s absolutely superb as a wetting agent, and seems to give a nice tightness to the grain.

But:

A. Does anyone know of longterm or immediate harmful/negative effects? Read the horror story from a printer here. But it seems to be user error.
Sistan (or alike) is neither toner nor a wetting agent; it is a silver stabilizer protecting residual silver from browning and silvering out.
B. How many times can you use a 500 ml batch? I’ve used it about eight times, mainly because It didn’t lather up, and it seemed cheap to be on the safe side.
But judging by the print instructions, you should be able to use it many more times.
Any experience?

C. Edit forgot this one:
There is no clear explanation of how long it should work and with what agitation.
So I just did one minute with inversions.
Right?

 

[AgX]

Diffusion takes time.
And a certain concentration has to be present for it not to be homeopathic.
If/when the emulsion is saturated with water that helps a lot. But it’s still not instantaneous.

I did it not questuion that, to the contrary. I gave an example of a similar process we are used to. One can take that time over.
However you had it before over the time for the stabilisr to "work", but that is not the case: the working of the stabiliser is in the future, if at all. So we only have to take into account here the diffusion time.