fixer mix of SodiumThio+Am.Chloride - could it be archival ?

here in Ukraine SodThio is 20 times less expensive than the only one proposition of Amm.Thio in bulk, and 5-6 times than cheapest ADOX AmThio factory produced.

We are trying to keep the tight line of affordable pricing to local clients and came to the point that buying ready factory mixtures is no way.

Coming to Thios - Ammonium is at present on the market or price is prohibitive. We think of using Sodium for local inexpensive papers and big prints/trays. Looking through soviet "cookbooks" we came to the idea of "middle" option of SodiumThio+Amm. Chloride to be in some 5 min fixing range instead of 10 min.

But that soviet cookbook of 1974 says that "prints intended to be stored for more than 20 years are not subj for fixing with Amm.thio due to formation of water insoluble salt in the paper". As I see modern theory came to the 1+1 min in Am.Thio procedure. Old school is 10 min in SodThio. But I see no info on this middle option of some Ammonium in fixer from Am.CL. addition. Looks like time would be about 5 min. But also looks like it might be having either worse of the two wolds (still long but impossible to wash out insoluble salts that have enough time to penetrate base) or best - faster than 10, cheap and still possible to be archival.

I tend to either stay with 1+1min Ammonium or 10min 2bath Sodium. But if there is any links to safety of "middle way" that you would advice It would be very helpful for our small photo society in UA.


PS soviet book says "for prints intended to be stored for more than 20 years 2 bath of SodiumThio fixer should be applied, with 2nd to be new/not working and time in it of 1/3 of total fixing. For print intended to be stored for more than 50 years 3 bath must be applied with 2nd+3rd to be new/not working".

Serg Lavrenchuk said:

here in Ukraine SodThio is 20 times less expensive than the only one proposition of Amm.Thio in bulk, and 5-6 times than cheapest ADOX AmThio factory produced.

We are trying to keep the tight line of affordable pricing to local clients and came to the point that buying ready factory mixtures is no way.

Coming to Thios - Ammonium is at present on the market or price is prohibitive. We think of using Sodium for local inexpensive papers and big prints/trays. Looking through soviet "cookbooks" we came to the idea of "middle" option of SodiumThio+Amm. Chloride to be in some 5 min fixing range instead of 10 min.

But that soviet cookbook of 1974 says that "prints intended to be stored for more than 20 years are not subj for fixing with Amm.thio due to formation of water insoluble salt in the paper". As I see modern theory came to the 1+1 min in Am.Thio procedure. Old school is 10 min in SodThio. But I see no info on this middle option of some Ammonium in fixer from Am.CL. addition. Looks like time would be about 5 min. But also looks like it might be having either worse of the two wolds (still long but impossible to wash out insoluble salts that have enough time to penetrate base) or best - faster than 10, cheap and still possible to be archival.

I tend to either stay with 1+1min Ammonium or 10min 2bath Sodium. But if there is any links to safety of "middle way" that you would advice It would be very helpful for our small photo society in UA.


PS soviet book says "for prints intended to be stored for more than 20 years 2 bath of SodiumThio fixer should be applied, with 2nd to be new/not working and time in it of 1/3 of total fixing. For print intended to be stored for more than 50 years 3 bath must be applied with 2nd+3rd to be new/not working".

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I suggest you try your mixture and conduct a residual-silver test. as long as all unexposed silver is removed, the prints will be 'archival after proper washing.brief sulphide toning will give additional protection; also consider two-bath fixing to be on the safe side; it will not increase fixing cost but make more efficient use of your fixer.

Take a look at this thread for some formulas and other information that may help: https://www.photrio.com/forum/threa...stitution-for-potassium-metabisulfite.147271/

There is no reason that a sodium thiosulfate/ammonium chloride fixer should not fix "archivally." Simply be sure not to exceed the capacity of the fixer. Two-bath fixing, like Ralph mentions, and testing for residual silver with either the Kodak ST-1 or Rapid Selenium Toner tests will give you confidence in your process. There is a lot of information here about everything you need. Google is your friend.

Best,

Doremus

I am not aware of insoluble silver or other salts that would be formed with Ammonium Thiosulfate and not with Sodium Thiosulfate. To the contrary: Sodium Thiosulfate is much more prone to forming insoluble compounds with Silver Iodide, which causes exhaustion long before Ammonium Thiosulfate.

Is there a chance, that Ammonium Thiosulfate back then had significant impurities, and that these impurities caused all the problems described in this old publication? Western public literature from the seventies knows nothing but praise for Ammonium Thiosulfate, and all modern fixer products are based on it ...

A rapid actinel fixer can be made from adding ammonium chloride to a sodium sulfite bath.

I have been using a mix of sodium thio and ammon. sulfate for a long time now, but only for film. There is no sign of deterioration in 10 year old negatives.
To be absolutely non-PC I buy my amm sulfate at the garden store. The Thio came from the pool shop.

Wow... didn't know it could be so easy
Actually Am.Cloride is so inexpensive (in 25 kg bags) here in Ukraine now and looks like more or less decent quality. I do not see there is much price sense try the garden store amm.sulfate. But thanks for the option.

At the moment I am using formula from the link hereinbefore that Rudeous proposed:

200 g/l Sodium Thiosulfate,
45 g/l Ammonium Chloride,
10 g/l Sodium Sulfite and
2,2 g/l Sodium Metabisulfite,

I use it 5 minutes. 4 minutes in bath A and 1 minute in tray B.

The biggest drawback of Sodium Thiosulfate based fixers (regardless of whether they contain ammonium salts or not) is their lower capacity with Bromide and especially with Iodide. Given the price difference between Sodium Thiosulfate and Ammonium Thiosulfate you will still be better off, especially when you fix Chloride/Chlorobromide based photographic papers. Before you use this for commercial processing, make sure you have a good handle on fixer capacity, especially with high iodide film stock.

Gerald C Koch said:

A rapid actinel fixer can be made from adding ammonium chloride to a sodium sulfite bath.

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Sodium Thiosulphate not Sulphite

Ian

Price vise this blend cost me about 0.25 USD / L of fix. With 2 trays 20-25 L each for 120x100 format print that is 10-13 USD per print session.
If I start any new project I could change fix baths to be sure and not worry/think about chemistry.

If I buy readily mixed chemistry it cost 1.3 USD per liter and more. Small difference in few litters but 50-60 USD per 2 trays. And with that price, I have to think about keeping it longer or add to the price of the print.
Jeneral price for the print nowhere calculated on the basis of cost of bw paper. Usually 4 times paper price. And that is already prohibiting level for a lot of photographers here in Ukraine to try BW enlargements from negatives. I explain that cause sure that price vise 0.25 or 1.3USD per litter of fix talk sound silly for people from US or EU...

There are drawbacks to this mix. Our chemist told me that in the hard financial times of 1990s made this mix option for the medical X-Rays cabinets. Medicine was on a very tough budget but must to x-rate somehow.
This formula due to Cl in it appeared so corrosively that is few months they had many machines made from stainless steel corroded to leaks. Thay abandoned that idea and moved on making own Am.Thio reactor.

We are using trays welded from stainless steel. But from the very beginning foud that welding beads were going to corrode very soon even from general use. So not we coated all the trays (made from stainless with PU Primer+Epoxy cover. Time after time we recoat that when chemistry finds cracks and go undercoating and about 5x5 to 10x10 cm areas flake aways. But that is once-twice a year and is much better than cleaning away new layers of rust from stainless trays every time. PU primer has nice light gray matt tone what is better that glazing stainless.

And also no metal tweezers for the fix baths. Personally, I like to use wide brushes to mix chemistry in big baths. Not sure about the practical sense of this procedure but it calms down nerves and get feeling of better done fixing. Also it takes away your hands and you do not stick it into the print so less chance to make dimples. Also time goig faster when you brush the print in chemistry. But all branches in the garden store have metal between hair and handle. So soon they also corrode and need to be changed.

Thanks for the advice.
I do not use it for the film. I am scary, especially for others films.

Will go and read it to some guys in the lab. When printing their own jobs they tend to go close to 0.5 m2 / litter for the first bath.
Personally, I try even not to come half of that throughput. After you note I guess if I am too positive about being safe with 0.25 m2 / l.

Once I asked a guy make contact prints from 21 step tablet to check contrast of new roll.
He found and used for that some old bottle of Ilford HYPAM fix maybe 10 years old (as I found the next day).
He left prints on my table and in the morning I took x-rite spectrophotometer to check densities. After some minutes I found that some contacts had tiny dark dots on them.
In ten more minutes, I have understood that dots were exactly in the centers of some light areas.
In a few more minutes I have found that dots were on the same field that had densities handwritten by me.
In a minute I got the idea - dots were on the measured fields only and were caused by densitometer light dot

When I found a 5l bottle with fix and emptied it - there were some maybe 1/5 of it taken by deposits (Sulfur I think).
The bad thing was that appeared that he printed that evening some extra sheets for his own client. We advised him to call the guy and advice to reprint those.

After that bad story, I go and check what capacity chemistry is used today when guys are printing for clients of the lab.
Sometimes they print overtime for themselves and their own clients renting a lab trying to use worked chemistry.
And I can't persuade USSR old schoolers. They say that were printing 40 years without problems with fixing like that and think that I am a moron.
Moreover - USSR old schoolers never used 2 fixing baths. "what for?!" is a usual question.

But... recently I had a talk with a photographer who got a call from a client about the deterioration of his hand-printed bw on the wall.
As I understood time period was 5 to 10 years framed under glass and the printer never used 2 bath fix at all.

Rudeofus said:

The biggest drawback of Sodium Thiosulfate based fixers (regardless of whether they contain ammonium salts or not) is their lower capacity with Bromide and especially with Iodide. Given the price difference between Sodium Thiosulfate and Ammonium Thiosulfate you will still be better off, especially when you fix Chloride/Chlorobromide based photographic papers. Before you use this for commercial processing, make sure you have a good handle on fixer capacity, especially with high iodide film stock.

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Ian Grant said:

Sodium Thiosulphate not Sulphite

Ian

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It depends on what was the final destination....

https://www.google.com.ua/search?bi...0.0....0...1c..64.img..0.0.0....0.E69qt9b_KjM