problem with bleach formula

[NewMexican]

Hello,
I made a liter of bleach using Tim Rudman's formula of 10g potassium ferricyanide /5g potassium bromide/ 1 liter of water. It makes everything disappear in seconds, very agressive. What am I doing wrong?
charlie

 

[pdeeh]

what are you wanting to bleach, and why ?

 

[NewMexican]

problem with too agressive bleach

I am using the aforementioned bleach on Ilford Mgfb with the intention of toning with the thiourea dioxide or FSA toner as described in Rudman's tome.
charlie

 

[cliveh]

So what happens after you tone?

 

[BMbikerider]

Is this not the same principal similar to Sepia toner? The bleach for this makes the image disappear but is brought back to life by the toning bath.

 

[NewMexican]

I diluted the bleach 1:8 and got some control over three minutes.
Then the toner
Really fast to a red tone over all. Like red brick. Way too much and way too fast.
Was Tim spinning a tale?
:

 

[pentaxpete]

I use those same chemicals for Sepia Toning bleach and they work OK -- it re-haloganises the Silver which is then converted into another form by the Thiocarbamide / Sodium Hydroxide toner.

 

[Ian Grant]

Ideally there should be a bit more Bromide if you're going to re-use the bleach for a number of prints. It is designed to work fast, it makes it easier to wash the remaining bleach from a Fibre based print.

Ian

 

[tim_bessell]

Ideally there should be a bit more Bromide if you're going to re-use the bleach for a number of prints. It is designed to work fast, it makes it easier to wash the remaining bleach from a Fibre based print.

Ian

Ian,

Not to high jack this thread, but is the speed factor the reason Sodium Carbonate is sometimes added to a bleach of this type? I'm thinking of PF's Thiourea Toner in particular.

Tim

 

[Ian Grant]

Ian,

Not to high jack this thread, but is the speed factor the reason Sodium Carbonate is sometimes added to a bleach of this type? I'm thinking of PF's Thiourea Toner in particular.

Tim

There's no reason to need to add carbonate. However it used to be recommended to soak prints which had been fixed with a hardening fixer in Sodium Carbonate (followed by a rinse) before toning to soften the emulsion. Someone posted last week that PF recommend usinga hardening fixer before toning, maybe that's why they add Carbonate.

Paper manufacturers recommend a non hardening fixer when toning prints.

Ian

 

[NewMexican]

I think that my Potassium ferricyanide/Potassium-bromide bleach is way too strong. It is not slow enough to allow for partial bleaching. I have seen so many strengths I don't remember which I used.
Any formulae here?
By the way, I am not using thiourea toner, I am using FSA> Dr. Tim gives a whole chapter to it.
charlie

 

[Ian Grant]

If you want partial bleaching dilute it as weak as you want, 1/10 or 1/50 of the normal working strength.

Ian