Bleach formula of Kodal Sepia II

[Andrew Moxom]

Okay, I have been experimenting with the Kodak Sepia II product and have to dilute the Pot Ferri bleach significantly as the stock solution is REALLY active. I dilute to about 1:10. That said, I discard the solution afterwards as I worry about longevity after so much dilution. I find that I use the pot ferri way quicker than the actual sulphide toner and am looking to make my own blend of pot ferri/bromide bleach that mimics Kodaks sepia II product.
does anyone have any starting points or recommendations for this mix of chemicals?

Thanks

 

[Tom A]

A simple mix for a bleach is:

Potassium ferricyanide 10g
Potassium bromide 5g
Water to 1000ml

This is working strength.

Tom

 

[Ian Grant]

A more common ratio is:

Potassium ferricyanide 100 g
Potassium bromide 100 g
Water to 1 litre

Dilute 1+9 for use.

If you use Sodium Chloride in placew of the bromide you get much warmer tones.

Ian

 

[Andrew Moxom]

Thanks guys

 

[dancqu]

Why the bromide, or chloride for that matter.
After the bleach the silver image exists as the
insoluble silver ferocyanide. How that image
might then tone in a sulfide bath I can not
say. Soon may know though as I've now
the P. Ferri. and sodium sulfide. Dan

 

[Rich Ullsmith]

You need rehalogenate the emulsion, or it won't be active in the developer or toner. Pretty sure if you if you bleach without rehalogenating, it goes poof. Like Farmer's reducer.

 

[dancqu]

You need rehalogenate the emulsion, or it won't be active
in the developer or toner. Pretty sure if you if you bleach
without rehalogenating, it goes poof. Like Farmer's reducer.

Farmer's reducer has fixer in it. Thiosulfate will dissolve any salt
of silver. The image should convert to silver sulfide. Dan