• Welcome to Photrio!
    Registration is fast and free. Join today to unlock search, see fewer ads, and access all forum features.
    Click here to sign up

Formula for copper based rehalogenating bleach

Mark Fisher

Member
Allowing Ads
Joined
Dec 13, 2003
Messages
1,691
Location
Chicago
Format
Medium Format
I am looking for a copper based bleach to use with second pass lith printing. I can't find my Tim Rudman lith book (ugh!) and I looked all over the web and I can't seem to find what I am looking for. I used some potassium ferricyanide bleach last night with some pretty interesting results, but I want to try a different bleach to see what the difference might be.

Thanks -- Mark
 

Ian Grant

Subscriber
Allowing Ads
Joined
Aug 2, 2004
Messages
23,370
Location
West Midland
Format
Multi Format
As a starter you could possibly use acidified Copper Sulphate and Potassium Bromide

Something like

Copper Sulphate (pentahydrate) 35g
Potassium Bromide 110g
Acetic acid (10%) 10ml
Water to 1 litre

Ian
 

trotkiller

Member
Allowing Ads
Joined
Feb 7, 2008
Messages
146
Location
København, DK
Format
Multi Format
Taken from page 99 of The Master Photographer's Lith Printing Course

Copper Sulphate 50 g
Sulphuric Acid 6.5 ml
Sodium Chloride 50 g
Water to 1 L

Dilute 1:9 for use
 

msonelson

Member
Allowing Ads
Joined
Dec 22, 2005
Messages
2
Location
Missoula, Mo
Format
Medium Format
A reader might note that Dr. Rudman's formula calls for concentrated sulphuric acid. If you are using the 48% sulfuric acid solution double the quantity to 13ml.