Ammonium chloride + Sodium Thiosulfate = Ammonium thiosulfate

Hello, i do most of my photo chemistry from bulk, but here in

portugal Ammonium thiosulfate is quite rare and expensive, what i´m

asking is if i mix a rapid fixer from mixing ammonium chloride and

sodium thiosulfate i get ammonium thiosulfate in the solution, rising

fixing speed, plus, i generaly use alkali fixer for films, but i mix

it like this: sodium tiosulfate 200gr

ammonium chloride 50gr

sodium sulfite 15gr

kodalk or sodium carbonate 10gr or 5.9gr

 

to 1 liter of working solution

 

this is a mix of 2 formulas agfa 304 rapid fixer and tf-2 alkaline

fixer, this way í was planning to make a rapid fixer from sodium

thiosulfate

 

clearing times are below 30 sec, i fix at least 5 min,

do i get the benefits of alkali fixers?

do i have to wash longer in a acid fixer with ammonium chloride and

sodium thio than with regular fixers???

am i doing right?

Yes, I have also read these old recipes for Rapid Fixers. If I remember it correctly, the mixing of Ammonium Chloride and Sodium Thiosulfate will make Ammonium Thiosulfate and Sodium Chloride.

 

Your questions are interesting, and I will come back here and read what the experts say. :)

Hello, I'm not the abovementioned expert, but I went down this road last year. Look at the thread

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=002awF

 

for this. Anders Ocklind suggested Agfa FX-Universal fixer which is slightly alkaline and here (Australia) is much cheaper than the Kodak and Ilford rapid fixers. It's primarily for colour processing, but it's also promoted as a B+W fixer for paper and film. I've been using it for all film and paper since then.

 

Your formula looks good to me. It should wash faster than acid fixer. Alkaline fixers don't smell nearly as much as the acid ones.

 

Following is a summary of some emails on the subject. Recently, Agfa has started to label it for B+W as well as C-41. Also, water stop seems adequate to me.

 

Anders Ocklind responded to a message you left in the B&W Photo - Film & Processing bboard:

Subject: Response to Formula for alkaline fixer

 

I use Agfa Universal Fix (C-41) 1+4 for B&W films and the same for B&W paper. Substitute 20% of the volume with fresh fixer after each filmdeveloping.

Paper:I use 2 bath method and measure the silvercontent with Kodak silverteststripes.

 

 

Subject: FX Universal developer

From: trevor.prestwich.tp@australia.agfa.com

 

The FX Universal can be used for Black & White papers at the following dilution,

1 + 7. You will need to use a stop bath between the developer and the Fixer. The

fixing time is the same as you would normally use for a normal, not rapid,

fixing bath.

 

We generally don't advetise the FX Universal for B & W as we have two other

fixers, MC & Agefix.

The FX Universal will do aproximately 1.5 sq m of Fibre based papers per litre.

Hope that you have success with it.

Regards

Trevor Prestwich

Applications Technology Manager

In one respect yes, there will be ammonium inos and thiosulphate ions in solution. But to get any significant concentration of ammonium thiosulphate you would need to remove the sodium chloride by fractional crystallisation. This isn't difficult because sodium chloride is not as soluble as ammonium thiosulphate and its solubility is fairly constant with temperature. By gradually evaporating the water, sodium chloride will crystallise out first leaving a higher concentration of ammonium thiosulphate. But for what's involved it would probably be easier to by Ilford Hypam.

that´s ok but hypam is an acid fixer and i want to make a rapid alkaline fixer from sodium thiosulfate, that´s it, more, no one knows if the rapid acid fixer made from sodium thiosulfate and ammonium chloride takes to longer washing times than with other acid fixers

 

thaks for the answers

I think it is important to know what you are trying to do to solve this problem. From what I've understood about Ilford Hypham, it is a non-hardening acid fixer. For the trouble to mix and use your own Amonium thiosulfate fixer you could just treat your Hypham-fixed prints in Kodalk as a pre-treatment for toning for five minutes --that is, if this is the goal. Kodalk will neutralized the acidity of a print. This will greatly reduce chances of staining. An important note is that Amonium Thiosulfate fixers used with extended fixing times will produce argentothiosulfates which are difficult to wash out of a print (see The Photographer's Cookbook). Ilford recommends a one minute fix time for rapid fixers for this reason. I do know a famous photographer that does two five minute fixes with Kodak rapid fix! (Minus the hardening solution).<P>Note on wash aids: Use Perma Wash for rapid fixers and hypo clearing agent on thiosulfate fixed prints. The former uses amonium bisulfite and the latter uses sodium bisulfite. (Just look for amonium based ingredients in your wash aids for rapid fixed prints, they'll work fine.)

My mistake: The reference was The Darkroom Cookbook.