What do I need to be aware of when making my own fixer?

[pkr1979]

Hi all,

I'm intending to mix up my own fix (Ive been using Ilford Rapid Fixer, and I now use Tetenal Superfix Plus)... but I dont know what kind of recipe I should use. And to be honest, I dont know what the difference is of a 'regular' fixer, a rapid one, and a hardening one (I get the the 2 Ive been using are rapid fixers, but I dont know if they are hardening fixers).

Ive been happy with both fixers, so its not out of dissatisfaction I want to make my own, I just want to try it

I'd like to use the fixer for BW neg film, BW reversal film, and paper... if that makes any difference...

Opinions? Or suggestions?

Cheers
Peter

 

[bedrof]

Have a look here.
https://www.photrio.com/forum/threads/a-neutral-quick-fixer-formula.157021/

A couple of weeks ago I mixed the fixer according to this recipe, it is easy to mix and works fine.

 

[Anon Ymous]

A regular fixer is one based on sodium thiosulfate and is rather slow. A rapid one, as the name implies, acts much quicker and is preferred if the raw chemicals required can be obtained. It is based on ammonium thiosulfate, although sodium thiosulfate can also be used as long as another chemical will be added that will practically make ammonium thiosulfate in solution. This is usually ammonium chloride, although it's not the only option. A hardening fixer is pretty much a relic of the past. There are very few cases where a hardening fixer is needed and they come with serious disadvantages. For starters, they're harder to wash, requiring long wash times.

Forget about hardening fixers and try mixing a rapid one. The fixer formula that @bedrof mentioned earlier is a good choice.

 

[Rudeofus]

There are a few questions you have to ask yourself:

1. are current available ready made fixers lacking in some way, or are you just curious about home brew in general?
2. do you have a good source of Ammonium Thiosulfate?
3. do you have a very cheap source of Sodium Thiosulfate?

In most cases, Ammonium Thiosulfate as raw ingredient is more expensive than rapid fixer off the shelf. Sodium Thiosulfate can be very cheap, but only, if you buy larger quantities.

If you want to enjoy the fun of home brewing, here are the fixer formulas you could take a closer look at:

• Ryuji Suzuki's neutral rapid fixer. Simple, reliable, easy to mix. Working solution lasts very long, because fixer is neutral.
• Rowland Mowrey's Superfix. Very fast fixer mixed from somewhat more difficult to obtain ingredients. If you follow the link: do yourself a favor and stop reading after about 10-15 replies.
• Bill Troop's TF-3. This is an alkaline fixer, with a very distinct smell. Some applications such as staining developers fare better with alkaline fixers.

If you have a very cheap source of Sodium Thiosulfate, you can try that quick fixer formula of mine, linked to already by @bedrof .

 

[Donald Qualls]

One more important difference between regular "hypo" fixer and rapid fixer is that non-rapid fixers don't work as well as we might hope for tabular grain emulsions (T-Max or Delta films, for instance) -- they can do the job, preferably when used in a two-bath format, but they don't last well and don't fix completely in a reasonable time as a single bath.

For traditional cubic grain (like Tri-X or Fomapan 400) they're fine.

 

[Rudeofus]

Sodium Thiosulfate fixers have mostly a capacity problem with high iodide emulsions. Issues with T grain were only reported, because they were high in iodide from the onset. There are certain poorly soluble mixed salts made from silver, sodium, bromide/iodide and thiosulfate. These mixed salts will form at sufficiently high levels of these four. A Sodium Thiosulfate plus Ammonium Chloride fixer can reach fixing speeds close to rapid fixer, but in terms of capacity it will be rather poor. This difference in capacity will be small with Silver Chloride papers, will be noticeable with Silver Bromide emulsions (papers and old films), and will be quite strong with Silver Iodide or Silver Bromoiodide emulsions (most modern films). This poorly soluble mixed salt does not form with Ammonium ion, therefore rapid fixers do much better with modern film.

Mixing this Sodium Thiosulfate (with or without Ammonium Chloride) fixer is really only worth the effort, if you can get the ingredients very cheaply and if hazmat disposal is also easy and cheap. In all other cases I would recommend one of these Ammonium Thiosulfate based fixers.

 

[Alan9940]

In addition to all the great info so far, you need to ask yourself: Do I need (want?) an alkaline or acid fixer? I prefer an alkaline fix for pyro developed negatives, but use standard sodium thiosulfate fix for paper. I don't shoot much T-grain type films, but when I do I use a rapid fix. As mentioned above, mixing a rapid fix yourself really isn't that cost effective. Another possible consideration is the volume needed. I need 5L for my tanks & hangers setup so mixing a standard formula is more cost effective for me. Most modern films don't need a hardener, but I do use a hardening fix for Fomapan 100 and EFKE 25.

 

[pkr1979]

Hey all,

And thanks for great feedback Regarding @Rudeofus questions, it is mainly about curiosity. Im happy with the Superfix Plus... but the concentrate has started to develop small crystals. I know this is probably not an issue, but one of the advantages of making your own is shelf life of powder (fixer might have long shelf life though - I dont know). Also, Im making my own developers and other chemistry so I thought I might have most of the ingredients, and I think I do except for the ammonium thiosulfate... I dont know how cheap I can get it, but there is a disposal facility nearby I can use.

What else... I shoot pretty much only TMY2 so I guess a rapid fixer is the way to go. When I develop as negative I do use Pyrocat, but I also develop BW reversal and Id like to use the same fixer for both... and paper. I'll have to read thru the posts once more to figure out how to do this though

Peter

 

[Donald Qualls]

The big problem with ammonium thiosulfate is that it's so hygroscopic (pulls water out of the air) that it's usually available only as a 60% solution -- which means you have to pay to ship liquid water (as opposed to only water of crystallization), which is heavy. I've seen it as powder, but then you have to deal with it picking up water in storage, so measuring by weight gets less and less accurate unless you dessicate it before each mix.

At least sodium thiosulfate pentahydrate won't gain moisture as it stands (though it will clump more and more, like salt in a box, you can just break up the clumps and weigh it out).

 

[Raghu Kuvempunagar]

Does this synthesis work? Has anybody tried it?

"Ammonium thiosulfate can be produced by mixing two solutions of ammonium sulfate and sodium thiosulfate, followed by cooling, filtration of the sodium sulfate."

 

[Anon Ymous]

Does this synthesis work? Has anybody tried it?

"Ammonium thiosulfate can be produced by mixing two solutions of ammonium sulfate and sodium thiosulfate, followed by cooling, filtration of the sodium sulfate."

I don't see why it wouldn't. At some point I even considered it, but sourced ammonium thiosulfate and forgot about it. Sodium sulfate solubility decreases greatly at lower temperatures, but ammonium thiosulfate not that much, so it will work, although you won't completely get rid of sodium sulfate in the solution, some of it will remain.

 

[Pioneer]

I use a lot of hypo because I have a very inexpensive source (basically free if I pick it up.) But I do use it as a two bath fixer and I regularly dispose of the first bath and rotate the second bath to first bath as capacity is very low. I usually rotate at 20 prints or films. It works great for prints and for films like AEU/Fompan 400 which I use a lot. I use a different fixer (TF-5) for TMX100.

 

[Raghu Kuvempunagar]

I don't see why it wouldn't. At some point I even considered it, but sourced ammonium thiosulfate and forgot about it. Sodium sulfate solubility decreases greatly at lower temperatures, but ammonium thiosulfate not that much, so it will work, although you won't completely get rid of sodium sulfate in the solution, some of it will remain.

Ok, I will give it a try. My problem is I can get Ammonium Thiosulphate for very good price but minimum order needs to be 25 litres which is too much for my needs. Sodium Thiosulphate and Ammonium Sulphate are fortunately available in much smaller quantities.

 

[Raghu Kuvempunagar]

• Rowland Mowrey's Superfix. Very fast fixer mixed from somewhat more difficult to obtain ingredients.

Can Potassium Thiocyanate be used in place of Ammonium Thiocyanate in this fixer? If yes what is the equivalent amount?

 

[Rudeofus]

Can Potassium Thiocyanate be used in place of Ammonium Thiocyanate in this fixer? If yes what is the equivalent amount?

Potassium will not cause a fixer speed loss, but it will greatly impact fixer capacity. The same thing, this poorly soluble mixed salt, which I described for sodium, applies in even stronger terms to potassium.

 

[Rudeofus]

The big problem with ammonium thiosulfate is that it's so hygroscopic (pulls water out of the air) that it's usually available only as a 60% solution -- which means you have to pay to ship liquid water (as opposed to only water of crystallization), which is heavy. I've seen it as powder, but then you have to deal with it picking up water in storage, so measuring by weight gets less and less accurate unless you dessicate it before each mix.

I bought a stash of Potassium Thiocyanate and powdered Ammonium Thiosulfate about 10 years ago. Within a few years the stash of Potassium Thiocyanate attracted so much water, that the salt completely dissolved in the attracted water. The Ammonium Thiosulfate stash is still unchanged. The biggest risk to Ammonium Thiosulfate is AFAIK not attraction of water, but slow release of Ammonia. The remaining Thiosulfuric Acid will decompose once dissolved in water. There are powdered BLIX kits comprising Sodium Ferric EDTA and powdered Ammonium Thiosulfate, so this decomposition process is quite slow. The biggest disadvantage of powdered Ammonium Thiosulfate is its much higher cost, therefore most people use the 60% solution.

BTW you should not get too hung up on the shipment of water in Ammonium Thiosulfate 60% solution: powdered Sodium Thiosulfate Pentahydrate contains just as much water than Ammonium Thiosulfate 60% solution!

 

[Doremus Scudder]

What I don't see anyone articulating clearly is that using Ilford Rapid Fixer or a similar product will likely be less expensive and certainly more convenient than mixing your own. I mix lots of things in my darkroom, but fixer isn't one of them.

Doremus

 

[revdoc]

I agree with Doremus. Based on 1+9 dilution, I find Ilford rapid fix to be far cheaper than making my own, even allowing for the added shipping. (I still keep sodium thiosulfate on hand for fixing alt process prints, but it's very dilute, so the cost is low. Not that I can use rapid fix in that situation, anyway.)

 

[Raghu Kuvempunagar]

Do Ammonium Thiocyanate and Thiourea work synergistically with Sodium Thiosulphate also as they do with Ammonium Thiosulphate? In other words, can a Sodium Thiosulphate based fixer be made faster by adding appropriate amounts of Ammonium Thiocyanate and Thiourea?

 

[Rudeofus]

Do Ammonium Thiocyanate and Thiourea work synergistically with Sodium Thiosulphate also as they do with Ammonium Thiosulphate? In other words, can a Sodium Thiosulphate based fixer be made faster by adding appropriate amounts of Ammonium Thiocyanate and Thiourea?

Yes, you can increase the speed of Sodium Thiosulfate fixer with thiocyanate and Thiourea. However, since capacity of thiosulfate fixers is much reduced in the presence of sodium or potassium ions, fewer people would spend much money on extra ingredients. I recommend Sodium Thiosulfate fixers only, if one has a very cheap source of Sodium Thiosulfate.

 

[Donald Qualls]

If regular (non-rapid) fixer will do the job for you, you can mix that very cheaply -- I've gotten sodium thiosulfate penta in buckets (they come as large as 25 lb., maybe bigger) at pool suppliers. Plain hypo without sodium sulfite works fine for one-shot use, and further you can use as little as about 1/4 the usual 240 g/L amount. You'll need to do clearing tests to verify the time for reduced concentration, but I used to figure I could mix plain hypo for use on RC paper and conventional grain films for about a nickel a liter. Make your own Parodinal with Costco acetaminophen at a penny a caplet, and you can develop and fix your Fomapan for about a dime and with barely more than a gallon of water including dilution and wash.

That said, these days I use rapid fixer that I got for next to nothing years ago (and still good). As noted above, it's the iodide that does it, but plain hypo doesn't work well enough on tabular grain...

 

[pkr1979]

I need a rapid one, so I guess this depends on if I can get hold of ammonium thiosulfate at a reasonable cost or not.

Whats the consequence of using a rapid fixer instead of an alkaline one when developing with Pyrocat ?

 

[koraks]

I need a rapid one, so I guess this depends on if I can get hold of ammonium thiosulfate at a reasonable cost or not.

Look for fertilizers based on ammonium thiosulfate. Some types of fertilizer are basically just a 60% solution of ammonium thiosulfate. It's cheap that way, but it may be difficult or even impossible to acquire small quantities (< 25 liters).

Whats the consequence of using a rapid fixer instead of an alkaline one when developing with Pyrocat ?

Rapid fixer and alkaline fixers are NOT mutually exclusive. I.e. you can make a rapid alkaline fixer, a rapid neutral one or a rapid acidic one, and the same for regular (sodium thiosulfate) fixer - it can be alkaline, neutral or acidic.
There's no distinct drawback to using an alkaline fixer for pyrocat negatives other than that its shelf life and capacity may be considerably less than an acidic fixer.
pH is fairly critical if you want the fixer to be effective, long-lasting and high-capacity. If you just want a fixer that works one shot for a short time, it's not very critical.

 

[Donald Qualls]

As I understand it, the main consequence of acid fixer after pyro developers is that the acidity tends to reduce the stain image, leaving a negative that's thinner and grainier (seeming) than one fixed in neutral to alkaline fixer.

Never tried pyro, myself, and staining Caffenol derivatives don't seem to be (as) affected in this way.

 

[Raghu Kuvempunagar]

the main consequence of acid fixer after pyro developers is that the acidity tends to reduce the stain image, leaving a negative that's thinner and grainier (seeming) than one fixed in neutral to alkaline fixer.

Is this a myth or is there experimental evidence for it?