Ammonium thiosulphate

Hello,
I could only find (in the European Union) the powder form of ammonium thiosulphate. The formula for TF3 fixer specifies a 60% ammonium thiosulphate solution. How can I obtain this solution using ammonium thiosulphate powder ?

Are you sure you have access to powder ammonium thiosulfate? Unusual to find in this form, very hygroscopic.
Easiest way to get a solution is buy plain rapid fixer from Ilford, Kodak etc.

Determine the specific gravity.

It is a fertilizer as liquid solution. You may asked any farm supplies store, but quanitites tend to be big.

First the answer to your question. The 60% must weight/volume. So, 600g of Amm.thio. for 1000cm3 final volume. Adding powder to a liquid increases the volume, less than one might anticipate, but 60%, is a lot. So start with less than the final volume (800cm3? 600?) dissolve the powder (probably need to heat) and adjust total volume.

Now what you did not ask.
1 - 60% amm. thio. is used as a fertilizer. Minimum order 1000 litre, but more commonly sold as a complete truckload. That is in France. Elsewhere might be different. Or you are lucky to live next to a farm that is willing to re-sell you a few litres.
2 - Making your own fixer is not economically viable (even if your time spent is "free") when comparing with "amateur" products (Ilford, Foma, Adox) and a clear loss comparing with fixer for C-41, which is just the same, but different market. The best deal I found:
From the recommended dilution and replenishent rates, I infer that for 25€ you have the equivalent of 4 litres of concentrated rapid fixer (Ilford, etc).
3 - As concerns the need for an alkaline fixer, see:

The dry form of ammonium thiosulfate is usually expensive, and for a 60% solution you need about 800 grams of the anhydrous form to make 1 liter of 60% w/w. You can get a ready-made concentrate from Mr. Suvatlar in Germany. I bought a 5-liter canister from him (it's quite heavy) and I'm satisfied.

mshchem said:

Unusual to find in this form, very hygroscopic.

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Not very unusual and it actually keeps quite well as long as it's kept in a tub/jar with a reasonably well-fitting lid.
It does tend to sulfur out a little bit with prolonged storage, so a fresh solution made with it will be slightly milky. This doesn't hurt, but if it's considered a problem, the solution can be filtered.

As the others have said, it's surprisingly difficult to obtain reasonable quantities of 60% ATS cheaply, given the fact that it's so widely used as a fertilizer. I think the main issue here is that most fertilizer products are compounded from a couple of materials, of which ATS is only one. Hence, it seems that the bulk 60% ATS solution is mostly sold to companies that compound these products for sale towards end users.

European seller, 65% solution. If you cannot find the anhydrous form, just add some water to this one.

Thank you very much for all your replies.

Here is the supplier reference where ammonium thiosulphate powder is available.

I wanted to check before if it was economically viable to make my own fixer. I currently use Rollei RXN fixer, which I buy in 5-litre containers, covering my needs for about six months. Indeed, this does not seem to be the case.

Can C41 fixer be used to process black and white paper?

Marc Charvet said:

Here is the supplier reference where ammonium thiosulphate powder is available.

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Yeah, quite expensive.

Marc Charvet said:

wanted to check before if it was economically viable to make my own fixer.

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Not really unless you can get fertilizer bulk quantities of ATS. Don't bother; many of us have explored this and about the best you can do is break-even with commercial fixers. What does help is to buy fixer in somewhat larger quantities, which tends to give you a better per-liter price.

Marc Charvet said:

Can C41 fixer be used to process black and white paper?

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Absolutely; it can be used for pretty much everything. B&W and color film, paper, alt. processes like Van Dyke, salt print etc.

Marc Charvet said:

Thank you very much for all your replies.

Here is the supplier reference where ammonium thiosulphate powder is available.

I wanted to check before if it was economically viable to make my own fixer. I currently use Rollei RXN fixer, which I buy in 5-litre containers, covering my needs for about six months. Indeed, this does not seem to be the case.

Can C41 fixer be used to process black and white paper?

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if my math is right, and it may be not, if you buy less than 10kg of powder you're paying more than buying the liquid solution.
As per liquid solutions, it appears that Suvlatar is slightly cheaper than my ebay link only in the 5L packaging (well, i'd have to do some more math to convert 65% to 60%, but...).

koraks said:

Not very unusual and it actually keeps quite well as long as it's kept in a tub/jar with a reasonably well-fitting lid.
It does tend to sulfur out a little bit with prolonged storage, so a fresh solution made with it will be slightly milky. This doesn't hurt, but if it's considered a problem, the solution can be filtered.

As the others have said, it's surprisingly difficult to obtain reasonable quantities of 60% ATS cheaply, given the fact that it's so widely used as a fertilizer. I think the main issue here is that most fertilizer products are compounded from a couple of materials, of which ATS is only one. Hence, it seems that the bulk 60% ATS solution is mostly sold to companies that compound these products for sale towards end users.

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When used as a fertilizer it's in a solution. Knifed into the soil.
In the US anhydrous ammonia is applied in late fall and during planting. Animal waste is collected by hog and poultry confinement operations and as a slurry and spread on the fields. Horrible smell. The slurry is shot out of bazooka like guns into the air. Ammonium nitrate is used in prell form.
Why the rivers are overwhelming polluted with nitrates high enough to create dead zones in the Gulf of Mexico

King corn, greater yields, bankrupt farmers, polluted water. Yields ethanol for fuel, cheap pork and chicken. Unsustainable.

I know what you mean @mshchem and it's the same around here. "Green fields" of monoculture. Where I live, the fields have two shades of green in summer: monoculture grassland and monoculture corn. Both are for beef & dairy. We import soy at a massive scale from Brazil where we chop down rainforest to grow the soy. This soy is then converted by our cows into manure. We have so much manure that only certain types of grass and corn can grow.

Fertilization is more subtle here; they used to use spray tanks as well, but that was banned a few decades ago. I think it was just too visible; we like to shove things under the carpet a bit more so we can pretend that all is well. Nowadays it's injected by arrays of shit injectors into the top soil. This happens to the extent that the soil can no longer bear it and the liquid manure overflows the soil and puddles on the field, or it simply flows in the many brooks/canals that were dug to drain the soil because otherwise the tractors get stuck too often.

We have totally and utterly raped this land. Most people don't realize because it looks green enough, doesn't it, and the cows look happy, too. We passed the mark of unsustainable by around 1965. For the past 60 years we've been living on borrowed time, propping up the system artificially. Sooner or later, some bug will turn up that eats corn faster than the cows can and that will be sufficiently resistant to the gallons of poison we cart onto the fields (so nice, those corn seedlings popping up in April...but hey...how come it's only corn...?) Something's gotta give.

Maybe at that point ATS will become cheaply available to us photographers because there'll be no other application for it anymore. There will be a brief moment when we get to eat all the cows and can do photography, before hunger sets in.

Thank you again for your detailed answers.

I will therefore abandon this idea, which has more disadvantages than advantages.

koraks said:

Absolutely; it can be used for pretty much everything. B&W and color film, paper, alt. processes like Van Dyke, salt print etc.

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I have not found any safety data sheets mentioning the chemicals used in C41 fixers: are they neutral or acid fixers ?