Lumpy
Established
I've just mixed up some xtol and intend using it at 1:1. I have a two reel tank and my question is this: if I develop two rolls of film, can I keep this used developer to develop another two or do I need to dump it out?
I think it's possible: since you can also use it at 1:3, it's not very probable that a 1:1 solution will be exhausted after developing two rolls
Xtol uses dimezone-s (a phenidone analogue) and isoascorbate as its developing agents. Ascorbates are effective developers of silver with similar efficacy at developing silver as hydroquinone. Ascorbates also can act as secondary developing agents - these regenerate the primary developing agent (but only above pH 9.5 for dimezone-s according to conventional understanding, and the pH of a working solution of Xtol is under pH 8.5) but ascorbates also act as a preservative like sulfite.
I tried translating this with 'Babel Fish' ... no luck! 😀
Dear Marty,It doesn't quite work like that. Xtol uses dimezone-s (a phenidone analogue) and isoascorbate as its developing agents. Ascorbates are effective developers of silver with similar efficacy at developing silver as hydroquinone. Ascorbates also can act as secondary developing agents - these regenerate the primary developing agent (but only above pH 9.5 for dimezone-s according to conventional understanding, and the pH of a working solution of Xtol is under pH 8.5) but ascorbates also act as a preservative like sulfite. Exactly how it works isn't really clear to me, but from experience the ascorbate seems to get exhausted faster than might be expected. Xtol seems to retain very little capacity after use except as stock, and even then to reuse it, you need to extend the time quite a lot or replenish it.
If you use Xtol diluted, use it one-shot.
Marty
It doesn't quite work like that. Xtol uses dimezone-s (a phenidone analogue) and isoascorbate as its developing agents. Ascorbates are effective developers of silver with similar efficacy at developing silver as hydroquinone. Ascorbates also can act as secondary developing agents - these regenerate the primary developing agent (but only above pH 9.5 for dimezone-s according to conventional understanding, and the pH of a working solution of Xtol is under pH 8.5) but ascorbates also act as a preservative like sulfite. Exactly how it works isn't really clear to me, but from experience the ascorbate seems to get exhausted faster than might be expected. Xtol seems to retain very little capacity after use except as stock, and even then to reuse it, you need to extend the time quite a lot or replenish it.
If you use Xtol diluted, use it one-shot.
Marty
Ok, I'm dead in the water now 😛😕😱
Does this translates to: "No, doesn't work !" ? I'm sure you're right, but I'm only a poor whatever-but-a-chemist 😉
Apparently the exact way that Xtol works isn't totally clear even to its inventors, hence the unusual 'minimum volume' requirements. I asked why, once, and the answer pretty much came down to, "It just does, all right?"