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I recently stopped using stop bath for both film and paper in favour of plain old water and the only thing I miss is the smell, I'm just addicted to it. Aggie, if you ever get to visit my darkroom when you came to the UK I promise that I shower every day.
Why not just get Sprint and enjoy a vanilla smelling stop ; )
I should have been more clear.
I use a water bath and TF4 fixer for film, always. The stop is for Azo, because a water bath would continue the development too long. So it's just for paper. And, if it matters..I use plain thiosulfate and bisulfite and then plain thio to fix the paper.
But after reading the interesting responses, I do have a question...isn't citric acid a developer, also? If you use it as a developer AND as a stop, how does the medium (film in that case, I guess) know when to stop developing???
I would be interested in making some rapid odorless top myself, if anyone has a good formula.
Thanks!
dgh
Ascorbic acid is a developer. Never heard of citric acid. For Ascorbic I assume since it's allegedly something that can be subbed for hydroquine that it acts in the same way. In other words it only develops with high pH levels. 11?? So in a stop bath it wouldn't develop. I guess you could use it for both your developer and stop then .
Robert is right. The developer is ascorbic acid, which works best in relatively high pH solutions.
Citric acid is simply a weak organic acid, which is what you want for a stop. Since it smells of citrus (lemon), most people find it less (ob)noxious than vinegar
You know, I think I was thinking of Citric Acid as vitamin C. I forget that it's ascorbic.
dgh
David, Funny, I almost made the same mistake the other day...Caught myself just before I let my mouth overload my....Oh well, you know what I mean.
So if I were to use citric acid as a stop, what would I need? And in what kind of dilution? I am actually a fan of water baths, so I would want to use just enough to stop development and keep the fixer fresher.
dgh
Had a quick look in the literature yesterday. Seems that 15g citric acid to 1liter water should do the trick. Don't know how long it will last, but citric acid is cheap and can be bought in most supermarkets...
used to preserve the color and such in fruit while preparing it to can....omg another area I have lots of knowledge in,,,home canning,,,darn farm girl upbringing.