Further to Pete's latest post:(posted 8628 days ago)Pete, I want to re-iterate that my experience may not have been an issue of alkai softening (or not)the emulsion, but more of a mechanical phenomenon as the alakai developer and acid fixer mix. Most chemical reactions are exothermic or endothermic, and the resulting temperature change which could soften (or seem to soften?) the emulsion (perhaps moreso than the alkalai?), and the by products of the reaction could outgas, or otherwise cause a dimensional change resulting in a softening. Most parts of the photographic process involve multiple actions.
On the other hand, perhaps it isn't the emulsion at all that softens, but the top anti-scratch coat?
I must admit that acid-hardening fixers have generally worked well for me, but it seems that keeping the whole process on one side or the other of pH 7 seems a better situation than crossing the line.
In over 30 years and I have had only one instance where the negatives have not remained stable, though the process was the same. And the only 2 times I damaged negatives with acid fixer were: 1) when I used Kodak rapid fixer without the hardener (early in my photgraphic life), and 2) the 8 x 10 sheet film I first mentioned.
I've avoided acid stop baths with films lately as I've had several instances of pin holes. I live in the San Francisco bay area, and our water has lots of impurities, so I use distilled water for developer and fix. Perhaps that the source of my experiences?
Perhaps I'll experiment to see if I now get the same results as you.
As far as TF-4 being archival, your comments cannot be refuted. It hasn't been around long, and may not be archival. Personally, I don't care if my negatives don't outlive me.