Sodium Thiosulphate (Hypo) - Lifetime
Does anyone know what the lifetime is of a 10% solution of Hypo? I have done some fixing of a couple of salt prints and then poured the solution back in the bottle (like I do with Rapid fixer) for re-use later. IS that OK...or should I be treating it as one-shot fixer? How can I test its suitability for re-use (eg some form of clearing test like for rapid fixer).
If it is a pure Hypo-solution (no sodium sulfite), then its lifetime is max 24 hour.
So use it and throw it away.
It's pure, so thanks for the pointer. Rgds, Kal
Does hypo dissolve well in propylene glycol, I wonder? The CRC says it's soluble in ammonia and insoluble in alcohol, but has no position on glycol. If it was amenable to a preservative solution the same way that phenidone is, that'd be convenient. (I assume ammonia wouldn't be a useful solvent for this purpose.)
I regularly use straight S. Thio. at 1% to 2%
Originally Posted by Shangheye
strength for fixing prints. Strength depends on
paper; fixer requirements vary. One-shot. Dan
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How long do you fix with that ratio? Twenty grams is about 1/10th of the usual minimum. And then there is the matter of how many prints will it fix.
Originally Posted by dancqu
Inquiring minds want to know.
I fix for 31/2 to 4 minutes. A single fix at such a high
Originally Posted by Paul Verizzo
dilution is all that is needed for greatest LE. The usual
strength of a sodium thiosulfate anhydrous fixer is
150 to 160 grams per liter; 15 to 16 percent. So,
1% for Slavich, 10 grams per liter. Good for 3
8x10s, each in 1/3 liter. Dan
Would welcome some thoughts as to why my Vandykes bleach out a bit when fixing in straight Hypo/sodium thiosulfate. I was under the impression that Vandykes should get darker! And yes, they do seem to be fixed :-)