B/W reversal bleach possible alternative?

septim · Oct 24, 2013

So while researching different caffenol recipies a while back I came across a post on a forum (Not APUG) that was talking about the impossibility of using a laundry Oxi Cleaner (Like Nappisan - though I dont know if that brand name means anything to anyone outside Aus/NZ) in caffenol because one of its ingredienrs would bleach the silver image from the film. Now I have no idea about the truth of that statement about the Oxi Cleaner and I had totally forgotten about that post until I was walking down the laundry isle of the supermarket. So if that statement about the Oxi Cleaner is true (which I am not entirely sold on) then could a solution of Oxi Cleaner be used as a bleach for reversal processing?

Gerald C Koch · Oct 24, 2013

NO, the only thing that this product and a reversal bleach have in common is the word bleach.

septim · Oct 24, 2013

Well technically they dont even have that in common. Any idea what could make someone say that about oxi cleaner bleaching (or perhaps stripping?) the image from film or were they just making an uninformed guess? The active ingredients are listed as Sodium Percarbonate, Hydrogen peroxide, Sodium Sulphate and Benzenesulfonic Acid.

Rudeofus · Oct 24, 2013

There are many patents for Silver bleaches based on Hydrogen Peroxide, and from looking at the redox potentials it is quite obvious that Hydrogen Peroxide will oxidize Silver (usually some catalyst is needed to unleash the oxidizing power of Hydrogen Peroxide).

Since this bleach was never intended to be used with films, there is a good chance that it will eat the gelatin and thereby destroy the film. If you feel experimental, take a short clip of some test film, expose it to room light, develop it to completion in some left over developer until it is completely black, then see what this bleach does to that test clip and the Silver on it. If the black Silver turns into white/grey milky stuff and the emulsion stays on the film base, you have successfully bleached your film.

septim · Oct 25, 2013

Rudeofus said:
There are many patents for Silver bleaches based on Hydrogen Peroxide, and from looking at the redox potentials it is quite obvious that Hydrogen Peroxide will oxidize Silver (usually some catalyst is needed to unleash the oxidizing power of Hydrogen Peroxide).

Since this bleach was never intended to be used with films, there is a good chance that it will eat the gelatin and thereby destroy the film. If you feel experimental, take a short clip of some test film, expose it to room light, develop it to completion in some left over developer until it is completely black, then see what this bleach does to that test clip and the Silver on it. If the black Silver turns into white/grey milky stuff and the emulsion stays on the film base, you have successfully bleached your film.

On Monday, when I next have some ID-11 I will perform a couple of clip tests and see how things turn out. I will post my results here once I perform the tests.

Edit: There is a clip test in some Caffenol now

Thanks for your input so far!

septim · Oct 25, 2013

Update: So it seems I screwed up with mixing the Caffenol and am so going back to the original plan of using ID-11 on Monday. This will allow me to focus on finishing shooting some slides over the weekend.

B/W reversal bleach possible alternative?

septim

Gerald C Koch

septim

Rudeofus

septim

septim

Privacy & Transparency

Privacy & Transparency