Plain sodium thiosulfate fixer

BetterSense · Jul 14, 2011

Like many, I have to mail order my photo supplies. Since I have large quantities of bulk chemicals, I don't have to worry about running out of developer. However, I sometimes run out of rapid fixer, and I hate paying to ship rapid fixer through the mail anyway. I would like to buy a pail of sodium thiosulfate and use it to make fixer. Questions:

Do I need any ingredients besides sodium thiosulfate to make fixer for both film and RC paper?

What proportions do I mix the powder with water?

Does anyone else use scratch-mixed sodium thiosulfate fixer? Is it economical to use it one-shot?

trexx · Jul 14, 2011

water 750 ml , warm
sodium thiosulfate pentahydrate 240 g
sodium sulfite anhydrous 50 g
water to make 1L

Does not last as long as the liquids concentrates . Good for maybe 6 weeks in stoppered bottle or one session in tray up to 25 prints.

c6h6o3 · Jul 14, 2011

BetterSense said:
Like many, I have to mail order my photo supplies. Since I have large quantities of bulk chemicals, I don't have to worry about running out of developer. However, I sometimes run out of rapid fixer, and I hate paying to ship rapid fixer through the mail anyway. I would like to buy a pail of sodium thiosulfate and use it to make fixer. Questions:

Do I need any ingredients besides sodium thiosulfate to make fixer for both film and RC paper?

What proportions do I mix the powder with water?

Does anyone else use scratch-mixed sodium thiosulfate fixer? Is it economical to use it one-shot?

Has anyone

I use Michael Smith's print fixer formula in two baths. I usually one shot them because the Chinese amidol paper developer I often use ruins the fixer. If I use Artcraft amidol I can add the bisulfite to the second bath from last session as use it as the first bath for the current session.

You can get both hypo and sodium metabisulfite at reasonable prices from the Chemistry Store. I find their shipping prices absolutely outrageous, however, so I always get the 50 lb. bag of Na2O3S2. That works out, including shipping, to around $2.00/lb.

I have never used plain hypo to fix film, although as I recall Michael Smith used to do just that until he met Paula and then began using rapid fix for his film.

Gerald C Koch · Jul 14, 2011

The usual form of sodium thiosulfate is the pemtahydrate commonly called "hypo" or "hypo rice". The large crystals look somewhat like grains of rice. There is an anhydrous form but it is more expensive and doesn't keep well. So if you switch to using the pentahydrate you are in a sense also paying to ship water.

There are numerous formulae for fixers on the web and in the APUG archives. They typically contain 200 to 300 g of hypo per liter. A plain fixer would also cobtain a small amount of sodium sulfite as a preservative. A hardening fixer would contain other chemicals like alum. A rapid hypo fixer would include ammonium chloride.

removed account4 · Jul 14, 2011

hi bettersense

i have this page bookmarked because i can never remember the amount of hypo/water

(there was a url link here which no longer exists)

its about 20-24% ... when i make it i don't put anything else in there, just sodium thiosulfate and water ...

good luck !
john

Ian Grant · Jul 14, 2011

Gerald C Koch said:
A rapid hypo fixer would include ammonium chloride.

An old fashioned Rapid fixer contained Hypo & Ammonium Chloride because Ammonium Thiosulphate was very expensive at one time and this was a cheap way to form it.

However these days Rapid fixers contain Ammonium Thiosulphate and no Chloride and are more efficient.

Ian

nworth · Jul 14, 2011

A plain sodium thiosulfate solution (240 g of sodium thiosulfate pentahydrate per liter of water) will work very well and is quite fast. But it has very limited capacity and life. It's great for a short session of a half dozen 8X10s or a couple of rolls of film, but not a lot more. Life and capacity can be extended by adding a couple of teaspoons (say 25 g) of anhydrous sodium sulfite. Some (like me) prefer to buffer the fixer near neutral with a teaspoon of sodium sulfite and a teaspoon of sodium metabisulfite. The sulfite seems to slow down the fixer a bit, but capacity and life are extended. You can make rapid fixer the same way by using about 190 ml per liter of ammonium thiosulfate solution. You could also add ammonium chloride and sodium sulfite to a sodium thiosulfate solution to make a rapid fixer, although this seems to be not quite as effective for some reason.

BetterSense · Jul 14, 2011

This sounds more complicated that developer. I think I will just go back to buying rapid fixer.

Gerald C Koch · Jul 14, 2011

Ian Grant said:
An old fashioned Rapid fixer contained Hypo & Ammonium Chloride because Ammonium Thiosulphate was very expensive at one time and this was a cheap way to form it.

However these days Rapid fixers contain Ammonium Thiosulphate and no Chloride and are more efficient.

Ian

The OP was interested in a cheaper alternative to ammonium thiosulfate solution. In portions of the US sodium thiosulfate pentahydrate is available cheaply from pool supply stores.

BetterSense · Jul 14, 2011

I've looked all over at pool supply stores and never found sodium thiosulfate. I also asked a small-time pool cleaner that I know if he had any or knew where to buy it and he had never heard of it. So at least in the Southern US, it's not easy to find as a pool chemical.

c6h6o3 · Jul 14, 2011

I've searched high and low for it here in the DC area at pool supply and chemical distributors. No joy. The Chemistry Store charges about $30 to ship a 50 lb. bag to my house in Maryland. Well worth it to me.

ic-racer · Jul 14, 2011

When you buy fixer from Ilford or another photography supplier you, indeed, are paying mostly for marketing and packaging. Take those two things away and you are 1) on you own finding a supplier (they won't be marketing or advertizing to you on the internet) and 2) without packaging, the product will arrive in 55 gallon drums to the port of your choice or arrive via tanker truck.

If you are getting the stuff packaged in smaller quantities from a chemical retailer with a web site, you are just taking sales away from the consumer darkroom photography industry.

brucemuir · Jul 14, 2011

What does PF charge for the pentahydrate?

Gerald C Koch · Jul 14, 2011

BetterSense said:
I've looked all over at pool supply stores and never found sodium thiosulfate. I also asked a small-time pool cleaner that I know if he had any or knew where to buy it and he had never heard of it. So at least in the Southern US, it's not easy to find as a pool chemical.

Many of the stores don't know what they are selling. Remember these guys aren't chemists. Ask for "chlorine neutralizer." Check the MSDS first because they sometimes sell sodium sulfite for the same purpose.

john_s · Jul 14, 2011

Gerald C Koch said:
Many of the stores don't know what they are selling. Remember these guys aren't chemists. Ask for "chlorine neutralizer." Check the MSDS first because they sometimes sell sodium sulfite for the same purpose.

In the pool test kits, one uses a drop of chlorine neutralizer reagent before the pH test which would otherwise be inaccurate. The neutralizer is thiosulphate solution.

Thiosulphate is used to get rid of excess chlorine in pools, but would normally be needed very rarely, since chlorine is expensive and the much more common problem is not enough of it. So it doesn't surprise me that most pool shops don't keep big quantities of it or even know much about it. My local pool shop (Melbourne Australia) has it in small quantities at a high price.

Gerald C Koch · Jul 14, 2011

john_s said:
Thiosulphate is used to get rid of excess chlorine in pools, but would normally be needed very rarely,

If you have to "shock" your pool then you are going to have a large excess of chlorine in the water. This is something we often have to do in Florida. Very humid here and there seems to be an abundance of stuff just waiting to infect a pool.

michaelbsc · Jul 14, 2011

BetterSense said:
I've looked all over at pool supply stores and never found sodium thiosulfate. I also asked a small-time pool cleaner that I know if he had any or knew where to buy it and he had never heard of it. So at least in the Southern US, it's not easy to find as a pool chemical.

Ask for chlorine reducer for pools that have been overshocked.

Those words make more sense to them.

jochen · Jul 15, 2011

Hello,
here the old and well proven formula of Agfa A 300:
Sodiumthiosulfate Pentahydrate: 200 g
Sodium- or Potassiumdisulfite (Na2S2O5, K2S2O5, also called "metabisulfite")): 20 g
Water to make 1000 ml, for film to make 800 ml.
The Disulfite is added to make it a little bit acidic. Formulations with Only sodiumsulfite are not acidic enough to neutralize developer alkali rests. Some formulations add 10 g Sodiumsulfite, anhydrous to 1 liter, it should give a better stability against formation of sulphur.

removed account4 · Jul 15, 2011

BetterSense said:
I've looked all over at pool supply stores and never found sodium thiosulfate. I also asked a small-time pool cleaner that I know if he had any or knew where to buy it and he had never heard of it. So at least in the Southern US, it's not easy to find as a pool chemical.

when i was in france a few summers ago, i went to a handful of pool / spa places
and looked at the chemicals ... no one had sodium thiosulfate.
and here in rhode island, i called 6 or 7 pool places ( like leslie )
no one carried it but one, i would have had to buy over a hundred pounds of it
and he was wasn't selling it any cheaper than getting it at a chemistry place.

just get it at the chemistry store as jim suggests, it isn't worth the trouble
of searching, wasting a day on the phone calling or going down to stores,
and then realizing after all that work it isn't any less expensive ...

john

Murray Kelly · Jul 15, 2011

Hypo is called 'chlorine lowering' chemical in the pool biz. Home pools don't bother but public pools buy it in bulk so you may need to question the bigger stores more closely as they probably aren't aware of its chem name.

Bassett11 · Feb 13, 2014

Still looking for the plain fixer?

I realize your post about the sodium thiosulfate fixer is very old, but I'm wondering if you're still wanting to use it and looking to buy?

Plain sodium thiosulfate fixer

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