Fogging redeveloper for B&W reversal

[avortex]

I've added my own formula at the recipes section (in alternative processes) to make a reliable fogging redeveloper:

(there was a url link here which no longer exists)

 

[removed account4]

I've added my own formula at the recipes section (in alternative processes) to make a reliable fogging redeveloper:

(there was a url link here which no longer exists)

so happy it is "normal" non hazardous materials.
thanks for posting this !
john

(edited later )
i've never heard of Hydrazine Sulfate ...
i hope it is easy to find, and it isn't like dichromate, or other
photographic materials that are crazy hazardous and hard to get rid of )

 

[avortex]

Have you tried plain dithionite?

Yes, I've tried and I dislike it. Not better than normal re-exposure method.
With this formula I get much superior results. Besides, it gets rid of the yellow cast that sometimes I got with Dithionite or re-exposure.
Cleaner highlights and better density.

 

[KPA40]

avortex,
have you also compared Hydrazine Sulfate with Stannous Chloride in the second developer?

 

[avortex]

Yes, I've tried a lot of different combinations with Stannous Chloride, but as it needs an acidic environment, it's very difficult to work with it and results have never satisfied me.
I've also used it as a separate fogging bath before the second developer. It doesn't work as well as this formula with Hydrazine.

 

[avortex]

so happy it is "normal" non hazardous materials.
thanks for posting this !
john

(edited later )
i've never heard of Hydrazine Sulfate ...
i hope it is easy to find, and it isn't like dichromate, or other
photographic materials that are crazy hazardous and hard to get rid of )

jnanian, you're right: I should have specified that Hydrazine Sulfate has to be treated with great care. Wear gloves, mix it with a mask, etc...
As many chemicals in the reversal process, like dichromate, it is a hazardous material.

 

[KPA40]

avortex, thanks so far. I have already ordered the stuff and I'll give it a try.
Now I have one question more. You wrote at the recipes section „dilute 1:3 and add 1g/l of Hydrazine Sulfate to this dilution“. I usually develop a single roll of film in a small Jobo 1510 tank with 250ml working solution, so I should add 0.25g in this case? Is there a special reason to add the Hydrazine Sulfate at this very last stage? I don't like it to handle with (hazardous) raw chemicals during development. I would prefer to add 3g/l to the stock solution when I mix up the redeveloper a day before or so.

 

[avortex]

Yes, for 250ml of working solution, you should add 0'25g.
About mixing the hydrazine sulfate in the concentrated developer... I don't know, because I haven't tested its shelf life.
Like you, I don't like the extra step of measuring and mixing chemicals while processing, so it's something I'll have to try.
Please, let me know if it works for you. And don't forget you have to add 4g/l at the stock solution instead of 3!

 

[pdeeh]

Hydrazine Sulfate has to be treated with great care. Wear gloves, mix it with a mask, etc...

This is one of those situations where the saintly Wikipedia lets us down - it makes no mention of the hazardous nature of this chemical.

The MSDS fortunately makes it very very clear, and this just emphasises the importance of even casual users of chemicals always referring to the MSDS before contemplating using them

 

[removed account4]

i know pdeeh,
i looked it up too, soon after i made my post ...

This is one of those situations where the saintly Wikipedia lets us down - it makes no mention of the hazardous nature of this chemical.

The MSDS fortunately makes it very very clear, and this just emphasises the importance of even casual users of chemicals always referring to the MSDS before contemplating using them

it is not even close to benign ...and i guess the answer is obvious why the OP didn't bother to even address my post.
i'll stick to using a bright light to fog my prints.

 

[avortex]

Well... I addressed your post before:

jnanian, you're right: I should have specified that Hydrazine Sulfate has to be treated with great care. Wear gloves, mix it with a mask, etc...
As many chemicals in the reversal process, like dichromate, it is a hazardous material.

I even specified it at the original recipe.

 

[removed account4]

thanks, i didn't see the post you made today addressing my concerns.