A 3-Year Durability Test: Copper Sulfate Bleach Still Working Perfectly!

[mohmad khatab]

Hi everyone,

I have a fascinating chemical observation to share. After being away from my lab for 3 years, I tested a bleaching solution I had prepared back then, and to my surprise, it still works with full efficiency!

The Formula:

• Copper Sulfate: 25g
• Ammonium Chloride: 25g
• Deionized Water: 500ml (Dissolve at a temperature near boiling).

Usage Instructions:

• Time: 6 minutes.
• Temperature: Should not be less than 32°C.
• Capacity: This 500ml batch is enough to bleach 10 rolls of film.

Important Technical Notes:

• No Pre-bleach or Post-bleach "Solutions" needed: This specific formula does not require a Pre-bleach solution or a Post-bleach solution.
• The Water Wash: It only requires a hot water wash after development and another after bleaching. The water temperature must be at least 38°C for a duration of no less than 3 minutes.

The Hardware Challenge: Unfortunately, while the chemistry survived, my film scanner is out of service because I lost the cables, the power adapter, and the Linux software configuration. I am working on getting it back to life soon.

Has anyone else experienced such longevity with this specific Copper Sulfate / Ammonium Chloride mix?

Best regards,Mohmad khattab

 

[Yezishu]

Thank you for the experiment. I'd like to ask if there's a source for the 32°C. requirement? This might be from an earlier experimental post? It seems dangerous for some films; would this formula work at 20°C?

 

[wiltw]

Depletion of developer is due to 'oxidation' (vs. 'reduction') chemical process while in storage, yet solutions that do not undergo 'oxidation' are long lived.

 

[Spektrum]

Thank you for the experiment. I'd like to ask if there's a source for the 32°C. requirement? This might be from an earlier experimental post? It seems dangerous for some films; would this formula work at 20°C?

How can a temperature of 32°C damage the film if the C-41 process is a high temperature process (38°C) ?

 

[Raghu Kuvempunagar]

Thank you for the experiment. I'd like to ask if there's a source for the 32°C. requirement? This might be from an earlier experimental post? It seems dangerous for some films; would this formula work at 20°C?

OP's use case is C41 films and so 32°C should be fine.

Copper Sulphate + Chloride bleach works at 20°C too but needs to be acidified for effectiveness. Can be used in B&W reversal processing in place of Dichromate/Permanganate bleach albeit with an additional clearing step.

 

[Yezishu]

OP's use case is C41 films and so 32°C should be fine.

Copper Sulphate + Chloride bleach works at 20°C too but needs to be acidified for effectiveness. Can be used in B&W reversal processing in place of Dichromate/Permanganate bleach albeit with an additional clearing step.

Thank you! That's what I wanted to know. The BW reversal post I saw before, as you said, added acid but didn't need this higher temperature.

 

[koraks]

This kind of bleach works fine at lower temperatures. Modern films have no problems withstanding 32C, color or b&w.

 

[mohmad khatab]

Hello everyone, may God bless you all. The bleaching solution can work at room temperature, no problem, but it will need more than a few minutes to be fully effective. However, in my personal experience, the best and fastest results you can get from this (miracle) solution are at 32 degrees Celsius, and it will only take a few minutes, no more than that, maybe even five minutes. But just to be extra sure, I'm adding an extra minute. This solution was given to me by my Ukrainian-Soviet colleague, Haji vova, who got it from old Soviet references. It differs from the traditional copper sulfate solution, which consists of copper sulfate and sodium chloride (without iodine), because this one contains ammonium chloride instead of sodium chloride. However, it won't work with tap water or distilled water; it only works with deionized water.

My greetings to my dear older brother, Mr. Raju, from India. I thank you from the bottom of my heart for forgiving my past foolishness and for coming to share my posts. May God bless you. You can't imagine how sad I was during my imprisonment because you were angry with me. A person remembers all the foolish things they've done when they sit alone in prison, with memories flashing before their eyes, constantly berating and punishing themselves for every mistake, big or small. I hope you will forgive me completely and sincerely, and give me another chance to learn at your photography school. I missed you dearly, and I told my fellow political prisoners about you. They now know (Hajj) Raju, the Indian, one of the greatest masters of black and white photography in the world. I will share my memories of my time in prison with you later, and how painful yet enriching it was. Regards.