It's strange that people talk about proprietary formulae of Ilford and EKC, but not the small company...(posted 8491 days ago)I just found on my old copy of "The Darkroom Cookbook" by Anchell that the pH of T-F4 (I guess it means TF-4) is 6.0 on page 37. This is not really alkaline to many people but that's ok. Did anyone confirm this pH? Incidentally, when I checked the pH of Ilford Multigrade fixer (working strength) the pH was at 6 range. I think at pH of 6, thiosulfate is easy to wash off because the pH is higher than gelatin's isoelectric point.
Ilford list sodium acetate and sodium bisulfite in the list of multigrade fixer's ingredients, and the pH seems buffered. One may want buffer the pH because pH too high may result in strong odor and too low may result in conventional acid fixer that requires long washing. Ok, it makes sense... What does TF-4 uses to buffer pH? (anyone thought about it?)
So, assuming that Anchell was right, how is TF-4 superior to Ilford Multigrade fixer, which is sold everywhere?
Finally, did anyone try to formulate own neutral pH rapid fixers?