Quote Originally Posted by CBG View Post
Interesting. I found this comparison of chemicals used as wash aid:

Solution........................pH at M/250...............Effectiveness relative
.................................................. ....................to pure water

Demineralized water...............~6............................ ...1.0
Sodium chloride.....................6.1.................. ........ .....1.5
Sodium bisulfite.....................4.1................. ..............2.8
Sodium sulfate.......................6.4................. ..............14
Sodium bicarbonate................8.4.................... ............49
Sodium sulfite........................9.2................ ....... ........87
Sodium hydroxide...................11.6.................. ............89

I don't remember where I dug it up, but your information seems like it fits.

C
It came from Haist, quoting other Kodak researchers.

The one common salt not listed which I think would be of "great" interest is sodium carbonate. I presume it would rate up there close to the hydroxide.

IIRC, Kodak HCA is sodium sulfite plus sodium bisulfite or some other acidic salt. I presume to lessen the swelling of the gelatin, which will give faster results.