sodium thiosulphate in place of Rapidfix?

Sim2 · Jul 2, 2012

Hi there,

Easy question for you guys here - I am thinking of trying sodium thiosulphate fixer (supplied as powder) instead of my normal Rapidfix, anything I should know about or be aware of in differences between the two types of fixer? Silly things, like does it smell bad, go off quickly etc etc.

I know it has no hardener in it, dilutes at different ratios and fixing times are longer. Anything else that is different that should be of concern?

Cheers guys,
Sim2.

removed account4 · Jul 2, 2012

sometimes it is mixed with a hardener, if you don't want hardening fixer you might want to make sure
what is in it ...

Photo Engineer · Jul 2, 2012

A Sodium Thiosulfate fix will take 2 to 4x longer to fix your normal film or paper compared to a rapid fix. So, test it first to determine the correct time for your film.

PE

cliveh · Jul 2, 2012

Photo Engineer said:
A Sodium Thiosulfate fix will take 2 to 4x longer to fix your normal film or paper compared to a rapid fix. So, test it first to determine the correct time for your film.

PE

Good advice.

Photo-gear · Jul 2, 2012

Something I would like to understand. Why does Sim2 want to avoid "hardener" in his fixer?

Sim2 · Jul 2, 2012

Photo-gear said:
Something I would like to understand. Why does Sim2 want to avoid "hardener" in his fixer?

Not sure about the smiley face meaning but I don't actually *want* to avoid hardener in the fixer and as I understand it Ilford Rapidfix (for example) doesn't have hardener anyway. Just thinking that just because one type of chems work ok without hardener, a different formulation to do the same function *might* require hardener. I do not know, which is why I was asking. Probbly a bad explanation but sort of makes sense to me!!

hrst · Jul 2, 2012

I think using a hardener in a fixer has been rather uncommon for many decades now.

Almost all commercial fixers available are non-hardening. The acidic ones are just COMPATIBLE with a hardener ADDITIVE which is sold separately. This does not make the fixer itself a hardening fixer. This seems to cause confusion every now and then.

For OP; if you are talking about PLAIN sodium thiosuplhate, it goes bad quickly and must practically be used one-shot. If you talk about a commercial PRODUCT that just is sodium thiosulphate based, then it most likely contains sulphite as a preservative.

Sim2 · Jul 2, 2012

hrst said:
I think using a hardener in a fixer has been rather uncommon for many decades now.

For OP; if you are talking about PLAIN sodium thiosuplhate, it goes bad quickly and must practically be used one-shot. If you talk about a commercial PRODUCT that just is sodium thiosulphate based, then it most likely contains sulphite as a preservative.

Thanks, this is the sort of info I was looking for.

I am specifically interested in a product from Silverprint (UK) called Silverfix (ref no 51713) on the following page:

http://www.silverprint.co.uk/ProductByGroup.asp?PrGrp=522

So I am guessing this may go off quite quickly. Perhaps an email to Silverprint beckons!

The heads-up is useful though.

Photo Engineer · Jul 2, 2012

Films and papers swell in developers. Swelling increases the chance of scratches. Cheap papers and films are very prone to this, but good films or papers are not. Good products usually come from Fuji, Ilford and Kodak. They are the hardest at this time.

Hardeners in fixers are usually useful then when fixing products from other manufacturers to prevent defects from handling.

PE

Photo-gear · Jul 2, 2012

Hardeners in fixers are usually useful then when fixing products from other manufacturers to prevent defects from handling.

As funny as it may look, i didn't know the use of hardener. Thanks for explaining to us!

removed account4 · Jul 2, 2012

hardeners trap the fixer into the emulsion and make it difficult to wash them free,
they also make it difficult to retouch the films with lead,
this was true in the 1930s as it is today.

Mark Fisher · Jul 2, 2012

Hardeners are also said to make print toning more difficult....

PhotoJim · Jul 2, 2012

With careful processing, hardeners in fixing baths are rarely necessary. One time they might be helpful is processing sheet film in trays, but it won't save you from rough handling before the film reaches the fixer.

Photo Engineer · Jul 2, 2012

There are pros and cons. You must determine which is best for your workflow!

PE

SkipA · Jul 2, 2012

I use Kodak F-24 fixer as described in The Darkroom Cookbook for all B&W film and paper. It works fine for me. One of these days I'll try TF-2 or another alkaline fixer just to see how I like it.

ruilourosa · Jul 3, 2012

you can make a rapid fixer with sodium thiosulfate by introducing about 40 gr of ammonium chloride per liter of solution, regarding hardener... PE: good materials does not mean hard materials, products like foma, efke, forte, maco, rollei, lucky, agfa, kentmere and some more, hold their own regarding quality but some have a bit more delicate surfaces WHILE WET!!
never had any problem although! and fomapan 100 in 8x10 especially with PMK is a must, also in €€€
here is a nice almost neutral fixer and easy to do:

H2O 52ºC - 750ml
Sodium THiosulfate - 200gr
Ammonium Chloride - 40 gr
Sodium bissulfite - 20 gr
Borax - 20 gr
h2o to 1 liter

borax plays the ph role but also eliminates the smell!

RalphLambrecht · Jul 3, 2012

it takes longer to fixand washout,but consider two-bath fixing anyway. it's the most efficient way to fix film and paper.

sodium thiosulphate in place of Rapidfix?

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