mohmad khatab
Member
How is this bleach?
Is it completely reliable?
Is it completely reliable?
And is the ammonia actually needed? If so, can I reuse it over multiple rolls? Thanks.
The Ammonia is critical to the bleach. You are converting silver to silver chloride as the first step. In the second step you rely on the much better solvency of silver chloride vs silver bromide in ammonia. So the ammonia dissolves the silver chloride without taking away much of the silver bromide.
It is reusable a few times. Read the warning about too much silver build up earlier in the thread.
silver fulminate
It definitely works. I have used this bleach a few times. I just don’t have any scans to post. You can see that it works in Athiril’s first post on this thread.Thank you for clarifying. Some folks on a discord server are giving me crap for thinking this would work at all. But it seems like it should, so I might just try it.
It definitely works. I have used this bleach a few times. I just don’t have any scans to post. You can see that it works in Athiril’s first post on this thread.
And are you using Copper Sulfate + NaCl + Citric Acid followed by household ammonia? If so, just a picture of the negatives would be appreciated, it doesn’t need to be super fancy.
I experimented with citric acid but the only totally successful full reversals I did was with this bleach linked by @Raghu Kuvempunagar earlier in the thread https://real-photographs.co.uk/formulae/toners/copper-sulfate-bleach/
Yes, it’s household ammonia. My sulphuric acid was drain cleaner.
Raghu posted a couple of images on Flickr. Here’s one
If no one posts anything better I can go digging around in my negatives (positives?) over the weekend
Alright, nice nice. Was hoping to use citric acid, as I don’t like the idea of Sulfuric acid. I would be afraid of it dissolving anything I have that would give me 6.5ml.
Alright, nice nice. Was hoping to use citric acid, as I don’t like the idea of Sulfuric acid. I would be afraid of it dissolving anything I have that would give me 6.5ml.
Is drain cleaner just sulfuric acid? I thought it had other things in it as well.
There are diluted sulfuric acid presentations, from 25-50% that are less dangerous and easier to measure (6.5ml turns into 26ml of a 25% dilution).
It could be quite difficult to get concentrated Sulfuric Acid,
the bottle of drain cleaner degrades over time, so does that mean I need to get a fresh one? Or can I use some that I have on-hand and just use a bit more than 6 ml to make up for any list acidity?
In Ireland you cannot buy battery acid, but you can buy "professional" drain cleaner in the mini-sized version of big box stores which we have over here, which is 30% sulphuric acid. This is what I used.Canada might be different, and EU surely is, but I bought concentrated sulfuric (sold as drain opener) in the Big Box store just a couple weekends ago. About $11 for a bottle that looks like a pint -- which at 6.5 ml at a time, is good for around fifty batches (it'll start to fail from water and CO2 absorption from air while the cap is open before I do that much reversal processing). Battery acid (30% strength) can be had at auto parts stores and I've used that for reversal bleach in the past.
"professional" drain cleaner
As long as you know what it is and how strong, you can make it work. Nothing I know of in photography requires undiluted concentrated acids (with the possible exception of making your own silver nitrate from metal -- and that wouldn't be sulfuric, would it?).
weird logic of what is allowed and not in various jurisdictions
Photrio.com contains affiliate links to products. We may receive a commission for purchases made through these links. To read our full affiliate disclosure statement please click Here. |
PHOTRIO PARTNERS EQUALLY FUNDING OUR COMMUNITY: ![]() |