Has anyone done B/W reversal with color bleach?

[RLangham]

Is this a thing that can be done? I'm talking about a three-bath color process where the bleach isn't combined with acid fixer.

Basically B/W reversal consists of
First development
Bleach -- often homebrewed with 9% hydrogen peroxide and citric or acetic acid
Reexposure
Water rinse (extensive)
Second development (can be same developer)
Fix
Wash

Since it's hard to get hydrogen peroxide where I'm at, will color bleach work? Or will it end up killing all the silver in the emulsion, not just the developed silver? If it does work, how long should it stay in the bleach?

 

[Ian Grant]

The bleaches used in Colour processing aren't suitable.

Ian

 

[koraks]

Is this a thing that can be done?

Depends on the bleach. It could work with a color reversal bleach (i.e. for color slides/transparencies). It's not going to work with a color negative bleach.

 

[RLangham]

Depends on the bleach. It could work with a color reversal bleach (i.e. for color slides/transparencies). It's not going to work with a color negative bleach.

Alright, that's what I thought. At some point I'll try to get some concentrated peroxide at a beauty supplier (I think most things are open in my town) and cut it down to 9%...

 

[Ian Grant]

Depends on the bleach. It could work with a color reversal bleach (i.e. for color slides/transparencies). It's not going to work with a color negative bleach.

A bleach for colour transparencies is little different to one for colour negatives, think about it, First Dev (B&W), stop or rinse, re-expose either to light or chemical fogging agent in the 2nd Developer (Colour dev), rinse or stop then Bleach followed by fix, or a combined Blix.

You need an entirely different type of bleach for B&W reversal that dissolves only the silver image formed in the first development and not the remaining unexposed Silver halides, Colour bleaches are more aggressive after all you need to remove all the silver image and residual Silver halides.

So the main two B&W reversal bleaches Use Potassium Permanganate or a Bichromate and Sulphuric acid to convert the Silver negative image to highly water soluble Silver Sulphate

Ian

 

[koraks]

Ian, you're right of course. I wasn't using my gray matter properly!

 

[RLangham]

A bleach for colour transparencies is little different to one for colour negatives, think about it, First Dev (B&W), stop or rinse, re-expose either to light or chemical fogging agent in the 2nd Developer (Colour dev), rinse or stop then Bleach followed by fix, or a combined Blix.

You need an entirely different type of bleach for B&W reversal that dissolves only the silver image formed in the first development and not the remaining unexposed Silver halides, Colour bleaches are more aggressive after all you need to remove all the silver image and residual Silver halides.

So the main two B&W reversal bleaches Use Potassium Permanganate or a Bichromate and Sulphuric acid to convert the Silver negative image to highly water soluble Silver Sulphate

Ian

And do remember that, in a pinch, C-41 and a basic b/w developer can develop E-6 slides. The bleach need not be any different than negative bleach.

 

[Rudeofus]

Since it's hard to get hydrogen peroxide where I'm at, will color bleach work? Or will it end up killing all the silver in the emulsion, not just the developed silver? If it does work, how long should it stay in the bleach?

Most color bleaches convert metallic silver to Silver Bromide. Typical reversal bleaches convert metallic silver into a water soluble silver salt, leaving the silver bromide behind. Note, that color bleaches are used after all development processes are done, whereas black&white reversal bleach is done before second development. Therefore color bleaches and reversal bleaches are fundamentally different. You can use a black&white bleach for color (assuming it doesn't attack the gelatin and the dyes), but you can not use a color bleach or BLIX for black&white reversal.

If hydrogen peroxide, potassium bichromate and potassium permanganate all become increasingly difficult to get, you could take a look at Athiril's cleverly designed copper bleach for black&white reversal. Athiril's bleach converts metallic silver into Silver Chloride, which can be dissolved in Ammonia, unlike Silver Bromide.

 

[RLangham]

You can use a black&white bleach for color (assuming it doesn't attack the gelatin and the dyes), but you can not use a color bleach or BLIX for black&white reversal.

Well, I certainly wouldn't use mixed Blix, since I am well aware that it contains acid fix, which is to say both a decent-sized amount of acetic acid, which is a potent stopping agent, and rapid fixer, which would render further development impossible even if the bleach didn't. My question regarded the uncombined bleaching agent only.

As for the technical details you bring up, thank you. That does make the absolute difference between color bleach and reversal bleach clear.

It's not that peroxide is at all difficult to get in itself where I am... it's that I would need pure peroxide at 9 percent solution or more, which isn't sold as a topical or oral debriding solution anymore where I'm from. I could probably obtain a much more concentrated form for bleaching hair from a specialty establishment, if one is still open, but I would worry about its purity. I may well just buy a reversal bleach like the ones you mention. I do appreciate the relative low toxicity of a solution of 9% peroxide and citric acid (lemon juice suffices, in fact) but I can live with something else if i must.

I have tried with the 3% solution of peroxide they sell at the drug store, but its action was incomplete even at inconveniently long time with agitation.

Anyways, it was just an idea prompted by the fact that I had a leftover set of unmixed Blix makings from a cinestill c-41 kit, and I had already made acid fix by mixing and diluting the other two components, leaving a bottle of bleaching concentrate. I thought "waste not want not," and popped in here to see if there was anything I could do with the stuff. It seems there is not, however.

 

[mohmad khatab]

Most color bleaches convert metallic silver to Silver Bromide. Typical reversal bleaches convert metallic silver into a water soluble silver salt, leaving the silver bromide behind. Note, that color bleaches are used after all development processes are done, whereas black&white reversal bleach is done before second development. Therefore color bleaches and reversal bleaches are fundamentally different. You can use a black&white bleach for color (assuming it doesn't attack the gelatin and the dyes), but you can not use a color bleach or BLIX for black&white reversal.

If hydrogen peroxide, potassium bichromate and potassium permanganate all become increasingly difficult to get, you could take a look at Athiril's cleverly designed copper bleach for black&white reversal. Athiril's bleach converts metallic silver into Silver Chloride, which can be dissolved in Ammonia, unlike Silver Bromide.

+1

 

[Donald Qualls]

I have tried with the 3% solution of peroxide they sell at the drug store, but its action was incomplete even at inconveniently long time with agitation.

Just in case you didn't -- you have to acidify the peroxide. Most folks seem to use either citric acid or acetic acid (white vinegar or stop bath). The 3% you can buy at the drug store is going to be slow and won't have much capacity; you might check your local beauty suppliers to see if they carry 9% or 12% for hair bleaching. Otherwise, Amazon lists 9%, 12%, and 35% (though the listing for the last is a little ambiguous; it may be "pre-diluted" to 12% or 9% strength).

BTW, 3% apparently works fine for paper, but may not work as well for the more silver-heavy emulsions in film.

 

[RLangham]

Just in case you didn't -- you have to acidify the peroxide.

Yes, I put a good deal of citric acid into it. I was trying to adapt someone's recipe, so I think I kept the amount of citric acid intact.

 

[mohmad khatab]

Well, I certainly wouldn't use mixed Blix, since I am well aware that it contains acid fix, which is to say both a decent-sized amount of acetic acid, which is a potent stopping agent, and rapid fixer, which would render further development impossible even if the bleach didn't. My question regarded the uncombined bleaching agent only.

As for the technical details you bring up, thank you. That does make the absolute difference between color bleach and reversal bleach clear.

It's not that peroxide is at all difficult to get in itself where I am... it's that I would need pure peroxide at 9 percent solution or more, which isn't sold as a topical or oral debriding solution anymore where I'm from. I could probably obtain a much more concentrated form for bleaching hair from a specialty establishment, if one is still open, but I would worry about its purity. I may well just buy a reversal bleach like the ones you mention. I do appreciate the relative low toxicity of a solution of 9% peroxide and citric acid (lemon juice suffices, in fact) but I can live with something else if i must.

I have tried with the 3% solution of peroxide they sell at the drug store, but its action was incomplete even at inconveniently long time with agitation.

Anyways, it was just an idea prompted by the fact that I had a leftover set of unmixed Blix makings from a cinestill c-41 kit, and I had already made acid fix by mixing and diluting the other two components, leaving a bottle of bleaching concentrate. I thought "waste not want not," and popped in here to see if there was anything I could do with the stuff. It seems there is not, however.

Peroxide 9% will not help at all
This liquid used in hair dyes will not work, it is not pure pure peroxide at all, it is intended for hair dye and is mixed with some other elements. I know this solution, my sister works as a hairdresser and when I have trouble getting this solution, I just gave her one ml of my peroxide and did what one liter of this peroxide of hair dyes did.
You need at least 70% peroxide.
- You are wasting time, my friend,
Copper bleach is very safe and everyone who speaks otherwise has no clue as to what it says.
Copper sulfate is mainly available at agricultural fertilizer stores, gardening companies, plant nurseries, plant sellers or farmers with agricultural land.
Maybe veterinary medicine maybe and it is very cheap
Sodium chloride is table salt (iodine stripped) or the lowest iodine content available.
- If you can get some of the sulfuric acid (battery water), this will be a good thing and if you cannot, there is no problem, you can whiten the negativity about 14 minutes with continuous stirring at a speed of at least 40 revolutions per minute. A temperature of at least 32 ° C.
It should be thoroughly washed with a cleansing solution after bleach for at least a minute.
is over .

 

[RLangham]

Peroxide 9% will not help at all

I have it on good authority that, if acidified, pure 9% peroxide can help. There was man, I believe, in Portugal (or was it Spain), who made B/W slides with caffenol-C, 9% peroxide from the pharmacy and lemon juice.

 

[Donald Qualls]

Around here, I can buy copper sulfate (crystals, which would be tetrahydrate, but easy to compensate by using more) at the Big Box store as tree root killer for drains. Purity is technical grade, not reagent grade, but that's fine for bleaching film if you want to use copper sulfate. You can buy table salt in both iodized and non-iodized form; the latter is still not reagent-pure sodium chloride, because mined salt (which this is) is actually sea salt that's been underground for geological time. However, because of the way naturally deposited salt is laid down, the layers that are mined for table salt are probably as pure as technical grade -- and cost fifty cents for a half kilo box. I actually prefer iodized salt for some photographic applications, the trace of sodium iodide helps sometimes. Battery acid (sold by Amazon, among other sources, or available locally from auto parts stores if they'll sell it, and you don't have to pay HazMat and wait for ground UPS) is 30% strength, so you have to compensate formulae for that factor.

 

[mohmad khatab]

I have it on good authority that, if acidified, pure 9% peroxide can help. There was man, I believe, in Portugal (or was it Spain), who made B/W slides with caffenol-C, 9% peroxide from the pharmacy and lemon juice.

Portugal and Brazil! I do not know ,,,
Forget all of this and do the guaranteed thing and don't waste your time and money. Trust me .
Copper sulphate is a guaranteed thing and has been tried many times successfully.
It's on Ebay here, five dollars.
This amount lives with you until the Day of Resurrection.
100 grams copper sulfate
100 sodium chloride
5 ml sulfuric acid (if available)
Deionized or distilled water up to one liter
Note 1: With tap water it will take more time and you may not get satisfactory results.
Note 2: The water temperature during mixing is not less than 52 ° C.
Note 3: It needs to be filtered with a coffee filter.
It's over

 

[RLangham]

Portugal and Brazil! I do not know ,,,
Forget all of this and do the guaranteed thing and don't waste your time and money. Trust me .
Copper sulphate is a guaranteed thing and has been tried many times successfully.
It's on Ebay here, five dollars.
This amount lives with you until the Day of Resurrection.
100 grams copper sulfate
100 sodium chloride
5 ml sulfuric acid (if available)
Deionized or distilled water up to one liter
Note: With tap water it will take more time and you may not get satisfactory results.
It's over

Oh, if it's that cheap, I suppose I have no excuse!

 

[mohmad khatab]

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