Sodium Thiosulphate as fixer help quick??

[mexipike]

Haven't been around here for a while but I'm back. I'm in a bind I'm working on a deadline and was getting ready to develop some film. I decided to mix a new batch of fixer and threw my old batch out like an idiot only to realize that I don't have any fixer. The photo stores are closed and I won't be able to get fixer for a couple of days (due to my real job) and really need to develop the film tonight. I do have a big tub of sodium thiosulphate in powder, and have seen people mention that it can be used although it's not ideal for archival standards. I'm going to fudge on the archival standards and go for it, any suggestions?? What ration should i use. Any suggestions on something I may have on hand or could get at the grocery store to add to it. I plan on using Xtol, an acid stop, (could be omitted if necessary) with tri-x 400. I also have some rodinal on hand.

Thanks,

John

 

[mexipike]

Looks like I may have most of my answers here-
(there was a url link here which no longer exists)
I'll wait a minute but then I'm going to start developing away.

 

[Anscojohn]

Plain sodium thiosulfate will fix ok; but you should use an acid stop bath. Plain hypo doesn't last very long, but for your one time need there should be no real problem. Most fixers use an approximately 25% solution of sodium thiosulfate. I use Ek F24, which is just 24% hypo, some sodium sulfite, and some sodium bisulphite. Ideally, you should let your mix stay in solution for a time before using. The old lab rats who taught me darkroom insisted nothing was any good unless it had been in the jug for twenty four hours.

 

[jim appleyard]

AFAIK, sod thio will fix to archival standards. Removing unexposed silver from film is removing unexposed silver from film. It's the washing out of the silver that makes it archival. Ammonium thio fixes film and paper faster and washes out faster, but both fixers do the same job.

Am I correct on this chem gurus?

 

[fschifano]

Yep. The sodium sulphite is there as a preservative. The sodium bisulfite is there as an acidifier. An acid fixing bath would go bad almost immediately without the sodium sulphite. Without the sodium sulphite, I'd be cautious about using an acid stop. You'll wind up carrying acid over to the fixing bath and without a buffering agent, you might have a problem. In this case, I'd use a water stop. Make it several changes of water with some agitation to clear as much developer as possible from the tank and the film. Other than that, there is no reason sodium thiosulfate cannot be used just as effectively as ammonium thiosulfate. Fixing times are longer, but so what? As long as you get the fixer and byproducts out of the film with a good wash, either type of fixer will leave you with archivally processed film. Oh yeah, it's the acid and hardener that makes washing more difficult, not the type of thiosulfate used.

 

[nworth]

Here is a generic acid fixer that should work well:

Acetic acid fixer (nonhardening)

Sodium thiosulfate (penta) 250 g
Sodium sulfite 5 g
Acetic acid (glacial) 5 ml
WTM 1 l

Fix 5 to 10 minutes, with some agitation. Sodium thiosulfate fixers are slower than ammonium thiosulfate fixers. You could probably omit the acid and up to sulfite to about 15 g to get a fixer that will wash out more easily but still have a reasonable life. Use an acid stop bath. Be sure to wash the prints thoroughly for archival stability, especially if you have fixed a quite a few. The silver thiosulfate complexes may not wash out as easily from this bath as from the usual rapid fixer. I'm not sure of the capacity for this one, but the thiosulfate content is similar to regular Kodak Fixer. Washing becomes more of a problem as more prints are processed, but the usual instructions for something like Kodak Fixer should work.

 

[dancqu]

I do have a big tub of sodium thiosulphate in powder,
and have seen people mention that it can be used
although it's not ideal for archival standards. John

The powder you say. May be the anhydrous form; no
attached water. If so a usual mix is 15%. Try to pin it
down. The penta has 5 molecules of water hanging on
so the usual strength is 24%.

That's all I use, film or paper. My formula a roll of 120:
sodium thiosulfate anhydrous 16 grams in 500ml of
water, 10 minutes with intermittent agitation.
A one-shot. No stop needed. Mixed fresh
at processing time.

Likely that 16 grams, a good half ounce, will do although
I've not tested with Tri-X. If you've not the time for
testing up to 20 grams for some margin. Up all
amounts 50% if you have the penta.

As for Archival, what you have read is from the bad mouth
of the Ammonium Manufactures International. Dan

 

[mexipike]

I finished developing all of the film, using around 25grams to to 500ml of sodium thiosulphate(it was penta). Everything came out fine. The first roll seemed to take forever, and in fact I ended up refixing them shortly after hanging them up to dry as they looked to purple to me. All in all at the end of the day everything went fine.
Thanks, so much for all your help. As I'm still out of fixer, and have lots of sodium thiosulphate I'll probably use it a few more times.

 

[dancqu]

I finished developing all of the film, using around 25grams to
500ml, of sodium thiosulphate(it was penta). Everything came
out fine. The first roll seemed to take forever, and in fact I ended
up refixing them shortly after hanging them up to dry as they
looked too purple to me.

All in all at the end of the day everything went fine. Thanks, so
much for all your help. As I'm still out of fixer, and have lots of
sodium thiosulphate I'll probably use it a few more times.

I processes only a few rolls of film each year. A fresh one- shot
fix seemed the way to go and sodium thiosulfate the chemical to
use. It's shelf life may be in the decades. A ten minute time limit
is reasonable and the amount of chemistry I've mentioned fits
that limit. The 25 grams penta, 16 grams anhydrous proved
good at least with slower film. Faster films have more
silver and thicker emulsions. With Tri-X 30 grams
of your penta may be better.

Slow it is. It is not rapid fix, the ammonium, and as used it
is at one fifth, 1/5th, normal strength. Used one-shot the
fixer is very clean. I don't bother with a stop, water or
what ever.

The Acros I've been putting through is loaded with pink out of
the fix. After the leisurely three stage Ilford wash sequence has
finished it's hard to tell if any color remains. Ilford's three stage
wash uses very little water; mine, room temperature.

For future rolls I suggest upping a little the amount of chemistry,
adopting something similar the three stage sequence, and keep
a jug or two of room temperature water at hand. Dan

PS: How many rolls of what format did you process.