Black and white reversal: Iron Out and fixing

[DeletedAcct1]

Thanks; to be honest, I never do this and just mix a small batch at a time. I use permanganate for clearing the DAS stain from carbon transfer prints. The 'official' documentation (Charles Berger, Sandy King et al.) suggest to use what is essentially a working stock permanganate bleach and dilute that for this particular purpose. I find this is (1) unnecessary and (2) counterproductive and simply dissolve a small amount of permanganate in plain tap water. I mix about 200ml at a time and this keeps fine for a couple of months (in the dark). I understand Calgon/hexametaphosphate can help even more; I don't have any handy and fortunately, even without this, the permanganate solution as such seems to be sufficiently stable for my needs (I've used it on occasion as a silver halide bleach as well, coincidentally!)

hexametaphosphate helps not only to avoid the plating out of the container but also, in a reversal setting, to avoid the formation of the purple/red patina in the emulsion (due to the permanganate reduction) that is difficult to remove even after a clearing bath.
That's what I found, with calgon I can prepare a one bottle only permanganate bleach ready to use. Adox is providing the bleach as one bottle only in their Scala kit, very convenient.

 

[koraks]

Interesting, and as you said, convenient.

to avoid the formation of the purple/red patina in the emulsion (due to the permanganate reduction)

Does a bisulfite afterbath help with this? That's what we use in carbon transfer. Permanganate to reduce the DAS sensitizer which leaves a stain, and the bisulfite to clear the stain and remaining discoloration due to the permanganate.

 

[DeletedAcct1]

Interesting, and as you said, convenient.



Does a bisulfite afterbath help with this? That's what we use in carbon transfer. Permanganate to reduce the DAS sensitizer which leaves a stain, and the bisulfite to clear the stain and remaining discoloration due to the permanganate.

Yes

 

[pkr1979]

Would the need for a fixer still be present if you are using a sodium carbonate+thiourea solution as the second developer? Or if you use a sulfur based toner as the second developer?

I assume both those alternatives would yield slides in a certain tone - but are there any suggestions for a toner that would be kind of 'neutral'?

 

[koraks]

With a thiourea developer I think you'd quite effectively convert all silver halide into silver sulfide. The slides will come out in shades of brown and yellow, of course. This can be beautiful if that's what you're looking for.

 

[pkr1979]

With a thiourea developer I think you'd quite effectively convert all silver halide into silver sulfide. The slides will come out in shades of brown and yellow, of course. This can be beautiful if that's what you're looking for.

If its too strong it might be a bit much. But if Im honest, the last couple of years Ive been looking for the most convenient way to do BW reversal (which is why I use dichromat and Iron Out). Ive also read that sulfur based toners can be used in the same way as a thiourea developer, and maybe there are som more neutral then the thiourea developer - but can any sulfur based toner be used?

 

[koraks]

Ive also read that sulfur based toners can be used in the same way as a thiourea developer

It's essentially the same thing. Thiourea + carbonate (or hydroxide) is essentially a sulfur toner.

there are som more neutral then the thiourea developer

I don't think so. Silver sulfide is brown, basically. You can influence the hue a bit, shifting it between a dark chocolate/purple-brown and a more yellowish burnt sienna brown - but thiourea is in fact the most flexible in achieving this, in my experience. Try using a little sodium hydroxide instead of the carbonate. I once did a whole toning gamut for thiourea sepia toning (the redevelopment step is what you're suggesting) where the hue was varied throughout this gamut. I must have the actual strips somewhere as well, but I plotted it in Excel for reference; here's the essence from that worksheet:

Working solution:	grams
100ml	.	NaOH	Thiourea
A	Yellow	5	10
B	.	7	7
C	.	8	5
D	.	9	3
E	Purple-brown	10	1

The molar ratio for yellow is around 0.5 (NaOH:thiourea) and 10 for deep brown.
With carbonate, you'll get the lighter hues due to a lower pH, I expect. I only did the quantitative tests with NaOH though.

I found that bleaching the prints (this was for B&W silver gelatin prints) with copper sulfate would create a sort of split-toned effect with blueish highlights, but this was really just a copper salt getting stuck in the emulsion; the whites would also stain pretty badly as I recall.

So yes, there are some ways to modify the tone, but if you're going to 'redevelop' using sulfer, you'll have to be content with some form of brown. This is especially the case in an application such as yours where you convert all silver halide to silver sulfide, as opposed to a print toning situation where you typically don't tone to completion.

 

[pkr1979]

Thanks for this @koraks Much appreciated.

 

[DeletedAcct1]

If its too strong it might be a bit much. But if Im honest, the last couple of years Ive been looking for the most convenient way to do BW reversal (which is why I use dichromat and Iron Out). Ive also read that sulfur based toners can be used in the same way as a thiourea developer, and maybe there are som more neutral then the thiourea developer - but can any sulfur based toner be used?

A potent redeveloper is an hydrazine derivative, quite toxic.
Another is tin(II) chloride, the same fogging agent as in E6 line. A recipe of which you can find in the Fomapan 100 R pdf instruction (on the Foma website).

 

[pkr1979]

A potent redeveloper is an hydrazine derivative, quite toxic.
Another is tin(II) chloride, the same fogging agent as in E6 line. A recipe of which you can find in the Fomapan 100 R pdf instruction (on the Foma website).

Ive been using tin(II) chloride, but Iron Out is more convenient. And as good with clear based films. Whats this hydrazine derivative stuff? Is it possible to get in solutions that keeps?

 

[DeletedAcct1]

Ive been using tin(II) chloride, but Iron Out is more convenient. And as good with clear based films. Whats this hydrazine derivative stuff? Is it possible to get in solutions that keeps?

Hydrazine sulfate.

https://www.cia.gov/readingroom/docs/CIA-RDP78B04770A002100090009-2.pdf

Please don't use thiocyanate in the first developer if the subsequent bleach is permanganate.
I would not use hydrazine.

 

[pkr1979]

Thanks @Alessandro Serrao . The recipe seems to call for fixing, so I see noe reason to use that instead of Iron Out. Some sort of Thiourea redeveloper might be a more convenient option then. Something off the shelf would be good

 

[Rudeofus]

Please don't use thiocyanate in the first developer if the subsequent bleach is permanganate.

If you put a wash between FD and B&W reversal bleach, then there should be no problem. I would not expect people to go directly from FD to B&W reversal bleach.

I would not use hydrazine.

I have - so far - never seen a source for any form of Hydrazine, at least not one which would sell to private individuals. There are some interesting Halochrome formulas out there with Hydrazine, so I did look.

 

[koraks]

I have - so far - never seen a source for any form of Hydrazine

Last time I was close to any was at a nuclear power plant.

I didn't ask them to give me any; I guess it must have slipped my mind.

 

[Rudeofus]

Last time I was close to any was at a nuclear power plant.

I didn't ask them to give me any; I guess it must have slipped my mind.

The PDF document link provided by @Alessandro Serrao marks Hydrazine Sulfate with an (*), and the footnote says, that it is a strong irritant and needs immediate attention. Sodium Hydroxide, Sulfuric Acid, Potassium Dichromate and Glacial Acetic Acid listed in the same batch of formulas bear no such (*) mark. This tells me, that Hydrazine Sulfate is not something you want anywhere near you.

 

[DeletedAcct1]

Thanks @Alessandro Serrao . The recipe seems to call for fixing, so I see noe reason to use that instead of Iron Out. Some sort of Thiourea redeveloper might be a more convenient option then. Something off the shelf would be good

I'd suggest part B of the Foma sepia kit, is based on thiourea.
It works very well, tested.

 

[DeletedAcct1]

The PDF document link provided by @Alessandro Serrao marks Hydrazine Sulfate with an (*), and the footnote says, that it is a strong irritant and needs immediate attention. Sodium Hydroxide, Sulfuric Acid, Potassium Dichromate and Glacial Acetic Acid listed in the same batch of formulas bear no such (*) mark. This tells me, that Hydrazine Sulfate is not something you want anywhere near you.

Exactly.
Also the Bellini reversal kit has a redeveloper in it that is based upon boranes, another kind of fogging specimen.
Bellini had problems with their previous redeveloper formulation, that was based on Sn(II)Cl which expired so fast that the redeveloper was useless. They switched to boranes.

 

[pkr1979]

I'd suggest part B of the Foma sepia kit, is based on thiourea.
It works very well, tested.

Thanks. How did you dilute it? And, do you know what its keeping properties are like?

 

[DeletedAcct1]

Thanks. How did you dilute it? And, do you know what its keeping properties are like?

The part B keeps for a very long time. I diluited it by trial and error, until I obtained the desided density.

 

[Rudeofus]

Exactly.
Also the Bellini reversal kit has a redeveloper in it that is based upon boranes, another kind of fogging specimen.
Bellini had problems with their previous redeveloper formulation, that was based on Sn(II)Cl which expired so fast that the redeveloper was useless. They switched to boranes.

The redeveloper working solution is very alkaline, which is not exactly becoming if you want to keep Stannous ions in solution. Not even ATMP will help you at pH 12.

 

[lamerko]

The redeveloper working solution is very alkaline, which is not exactly becoming if you want to keep Stannous ions in solution. Not even ATMP will help you at pH 12.

If SnCl is in separate solution, will it have good stability?

 

[Rudeofus]

If SnCl is in separate solution, will it have good stability?

I have never had a bad experience with Stannous Chloride, but PE adamantly warned be about its "sudden death" syndrome. It is a very powerful fogging agent and will work until really almost no stannous ions are left in solution, and then it will suddenly collapse, i.e. become inactive from one moment to another. It also doesn't change color when it oxidizes, and being a strong reducer of course it oxidizes well in air.

If you make the concentrate to Kodak's spec (see my 5l kit formulas), then you can assume, that the concentrates will last for a while. As soon as you move away from that, you are on your own, and as described, this can work a long time until it suddenly doesn't.

You can easily test reexposure bath with unexposed B&W film, but then again you have some residual risk, that it fails between test and actual run. I would not keep the working solution for more than two weeks.

 

[lamerko]

I've always wondered, what exactly does p-aminophenol do in this formula? Can it be skipped?
I have some, I don't care, but this amount is...