ammonium thiosulfate longevity

[lensmagic]

Over time, does a stock solution of 60% ammonium thiosulfate lose its effectiveness as a fixer? Is it advisable to test for clearing time every so often?

 

[Photo Engineer]

I have had some keep for 5+ years with no problem.

PE

 

[lensmagic]

Hi, PE, if I wanted to speed up the fixing process by decreasing the dilution, is there a concentration of ammonium thiosulfate that should not be exceeded? For example, could the working solution be 20%? 50%?

 

[paul ron]

i saw ammonium thiosulfate also listed as liquid fertilizer. is this the same as rapid fixer?... perhaps cheaper too?

 

[Photo Engineer]

There is a chart in Mees and Mees and James. I won't do your research for you and I don't remember it OTOMH. So, look it up. It is quite effective over a wide range as Mees shows. The results are true for both Sodium and Ammonium Thiosulfate so don't worry about the "names" in the references.

Fertilizer may be different. I would hate to recommend it. It could contain a lot of Ammonium Nitrate.

PE

 

[paul ron]

thanks. i just thought sometimes generic chemicals are used for other applications are exactly tge same aside from labeling....

 

[lensmagic]

There is a chart in Mees and Mees and James. I won't do your research for you and I don't remember it OTOMH. So, look it up. It is quite effective over a wide range as Mees shows. The results are true for both Sodium and Ammonium Thiosulfate so don't worry about the "names" in the references.

PE, I believe the charts in Mees and Mees and James are Figs. 141 and 142, pp. 521-22. The max seems to be 30% to 40% 15% looks to be ideal. Sorry I can't copy the images or text.

 

[StephenT]

I can't find a book by Mees, Mees, and James. But I found a third edition by Kenneth Mees and a fourth edition by TH James. Are these the same books, just later editions?

EDIT: I did find a hardback by the two Mees along with James, copyright/publish date 1936. Along with a biography of Kenneth Mees by TH James published in the nineties, so am I correct in assuming that the fourth edition, 1977, will be a satisfactory reference?

 

[Alan Johnson]

See fig 8.1 on p135 here:
https://babel.hathitrust.org/cgi/pt?id=mdp.39015016032883;view=1up;seq=147

 

[lensmagic]

thanks. i just thought sometimes generic chemicals are used for other applications are exactly tge same aside from labeling....

I can't find a book by Mees, Mees, and James. But I found a third edition by Kenneth Mees and a fourth edition by TH James. Are these the same books, just later editions?

Hi, the Figures I found were in Theory of the Photographic Process, by C. E. Kenneth Mees, 1942. Apparently this was the first edition. Sorry for the confusion.

EDIT: I did find a hardback by the two Mees along with James, copyright/publish date 1936. Along with a biography of Kenneth Mees by TH James published in the nineties, so am I correct in assuming that the fourth edition, 1977, will be a satisfactory reference?