Hypo clear?

[reddesert]

Here is an MSDS for Perma Wash that lists a couple of ingredients: https://art.illinois.edu/images/docu...-Permawash.pdf
Ammonium sulfite and sodium ethylhexyl sulfate are the two listed.

Ammonium sulfite is close to the same sulfite ion per molecular weight as sodium sulfite. I don't know if ammonium sulfite acts faster or more efficiently than sodium sulfite. I washed longer than their (IIRC) somewhat absurdly short recommended wash times. Perma Wash is a little more convenient and/or stock solution is longer lasting than Kodak HCA, but if one is making wash aid from sodium sulfite that's less of an issue.

I have films and RC papers from 20-25 years ago that were wash-aided with Perma Wash and don't seem to have degraded, but no fiber base papers, and I didn't do residual fixer tests.

(By the way, why does ammonium thiosulfate (rapid fixer) fix faster than sodium thiosulfate? I wondered if that was related, but couldn't find an answer, even though it is presumably well understood.)

[alt.kafka]

I put 12.5g of HCA in 500mL of warm water with a magnetic stirrer at the start of each session. It's kind of hard, so the heat and the stirrer help it to be completely dissolved by the time I need it.