Aging of Stop bath?

[winger]

I have a bottle of Kodak indicator stop bath that has been opened, but very little has been used. I don't know how old it is, but probably 15+ years. Is it likely to be fine for use? Especially considering that water could be used in its place.

 

[MattKing]

When I was doing only a portion of my darkroom work at home, I used a large bottle of Ektaflo indicator stop bath for almost a decade, with no apparent ill effects.

 

[largely]

I recently discovered a 3/4 full bottle that had been in storage for about 22 years. Worked fine as far as I could see.

Larry

 

[Bob-D659]

Just be careful if the bottle is plastic, acid helps the age hardening, I managed to twist a bottle apart trying to get the cap loose, luckily over a sink.

 

[jerl]

The main purpose of the stop bath is to neutralize the developer to stop development and to wash it out to prevent it from contaminating the fixer, so there's too much it needs to do, and there's not too much that can go wrong. Sometimes, people would use just plain water for this (although you have to be more careful).

 

[ic-racer]

If you have access to something like a Fox 4000 electronic nose, you could test it
http://www.insung.net/cgi/pdf_new/20/30 Vinegar.pdf

 

[PhotoJim]

Sometimes, people would use just plain water for this (although you have to be more careful).

Plain water works well if you use an alkaline fix. I tend to always use stop with acid fix, but never with alkaline. (I use a 60-second running water step with alkaline fix.)

Acetic acid stop bath concentrate like Kodak's is nearly immortal so I'd trust it. I'm not sure how long-lived the citric acid-based ones like Ilford's are; I've never kept one long enough to see.

 

[George Collier]

It's probably still good. Just try it, you can tell if it's not working, the stop bath starts to feel slimy (alkaline, like the developer), even if the dye stops changing color.

 

[Ian Grant]

It'll be fine. I'm still using Acetic acid to make up stop bath that's well over 20 years old, works perfectly.

Ian