What was Edwal Thermo Salt?

juan

Member

Joined

May 7, 2003

Messages

2,706

Location

St. Simons I

Format

Multi Format

• Apr 17, 2021

• #1

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

Member

Joined

Aug 31, 2015

Messages

772

Location

New Hampshire

Format

Multi Format

• Apr 17, 2021

• #2

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

it is sodium sulfate

 

OP

OP

juan

Member

Joined

May 7, 2003

Messages

2,706

Location

St. Simons I

Format

Multi Format

• Apr 17, 2021

• #3

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

Member

Joined

Nov 20, 2002

Messages

138

• Apr 17, 2021

• #4

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

 

Bill Burk

Subscriber

Joined

Feb 9, 2010

Messages

9,318

Format

4x5 Format

• Apr 18, 2021

• #5

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

 

Attachments

• 9DD1ECD4-44D3-46DD-B160-88B92FBD5ED3.jpeg

  116.9 KB · Views: 57

OP

OP

juan

Member

Joined

May 7, 2003

Messages

2,706

Location

St. Simons I

Format

Multi Format

• Apr 18, 2021

• #6

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.