What was Edwal Thermo Salt?

[juan]

I’m reading an old Edwal book and see several references to adding Edwal Thermo Salt to developers at high temperatures. What was it? My search engine finds no reference.

 

[fgorga]

According to this thread...
https://www.photrio.com/forum/threads/edwal-thermo-salts.103479/

it is sodium sulfate

 

[juan]

Thanks. Interesting how the search engine here works. I searched for salt - singular, and it didn’t turn up. That post uses salts - plural.

 

[LFGuy]

Kodak J-1 has some guides on using sodium sulfate (page 19 of my copy).

 

[Bill Burk]

And... because you reduce swelling, the developer doesn’t penetrate as much as it otherwise would so you treat the developing time as if it were 5 degrees F cooler

 

[juan]

I might have tried using it at my previous place in Florida. My water pipes ran through the attic, so my cold water temperature was 80F even in the winter.