Whoops, Xtol-R contamination issue.

[Rowreidr]

I've been running a batch of Xtol-R (replenished) since receiving my replacement, using a 2.5L bottle for working and doing nearly all of my developing with it. More recently, I bought the raw chemicals and started a batch of d96-R for a bulk roll of 5222 (double x) and have done several rolls. The working bottles are the same (Eternal spring water), clearly labeled, and the replenishing solutions are in different sized and clearly labeled wine bag thingys.

Monday, I developed a roll of P3200 in Xtol-R (the first in a few weeks) with no issues. Today, I was going to develop some expired Tmax100. But, as I was going to pour out the developer, I realized that I had pour 60cc of d-96 replenisher into my Xtol working solution on Monday.

So, should I dispose the Xtol or pretend it didn't happen? I am going to test the developer, but right now all my developing tanks are filled, so I thought I would ask here as well, in case someone wise can guide me and save me some hassle.

Thanks!

 

[Donald Qualls]

The "correct" way would surely be to discard the contaminated Xtol working solution, wash, and refill the bottle with fresh replenisher (stock solution) and restart your seasoning (or use a starter if you have one -- I don't know if there's one sold, but I'd bet it's possible to mix one).

With the high replenishment rate of Xtol, however, if you aren't picky about your negatives you could probably just pretend it didn't happen. You'll have "off" negatives for the next dozen or more rolls, but you'll still get images, and over time the working solution in the bottle will change more and more toward pure Xtol again.

 

[Rowreidr]

Thanks, Donald. I was close if not at equilibrium with my xtol-r, that I don't really want to start all over (I didn't use and don't have starter). It is a low dilution 60/2500cc, and I do have relatively low standards, but knowing that I have d-96 floating around bothers me a little. I have less than 1000cc of replenisher left, so I guess I will finish that with my less important rolls, and then go from there,

 

[Donald Qualls]

If you don't do sensitometry, you might well not notice the difference with 60 ml of D-96 replenisher in 2.5 L of working solution. Of course, the large working solution volume (by home darkroom standards) means it'll take longer to work out the D-96, but at worst you should see a very small decrease in contrast. D-96 is and MQ developer, vs. PC for Xtol, so you may also see a (very) small loss of film speed.

The biggest thing to watch for is Xtol failure that could be caused by iron or copper contamination in the D-96 replenisher (Fenton reaction, destroys the ascorbate). Chemicals used for D-96 don't need to be as carefully controlled as those that go into Xtol, but on the other hand, Kodak has had a sequestrant in their Xtol for many years now, so again, with the small quantity of contamination, it's not likely to become a problem.

 

[Rowreidr]

I was worried about the vitamin C part. So far I have developed a roll of expired Tmax100, which I have never shot before, and 2 rolls of fp4+ @1000, which look similar enough to prior negatives, though still waiting for them to dry. Looks like I have 8 more rolls that I am willing to develop with this batch, so I'm just going to let the developer sit for a few days, to see if anything precipitates out, and then see what happens.

 

[Andrew O'Neill]

I wouldn't worry about 60ml in 2.5 litres. Eventually, it'll work its way out.

 

[removed account4]

So, should I dispose the Xtol or pretend it didn't happen? I am going to test the developer, but right now all my developing tanks are filled, so I thought I would ask here as well, in case someone wise can guide me and save me some hassle.

Thanks!

I wouldn't worry about that tiny amount, but ...
you might want to run a test, mix the 2 developers together 1/2 1/2 and see if you like the results ? I know Pat Gainer ( I think it was him ) used to mix rodinal and xtol together. maybe you will like your proprietary mix

have fun!
John

 

[Rowreidr]

Thanks for your thoughts. I have read about rodinal+xtol in the past. I'm not going to stress as much about this and just keep eye on it. It's funny how I have grown fond of my bottles of replenished developer.
Patrick

 

[Donald Qualls]

you might want to run a test, mix the 2 developers together 1/2 1/2 and see if you like the results ? I know Pat Gainer ( I think it was him ) used to mix rodinal and xtol together. maybe you will like your proprietary mix

Worth noting that this is generally only suitable (with testing) for one-shot developer use. In replenishment, especially where one developer is self-replenishing with resulting near-infinite potential lifetime, and the other is not (hence usually would be discarded after replenisher consumed equals working solution volume), it makes little sense (IMO). Just as you'd only mix Rodinal with Xtol for one-shot, I'd only mix Xtol and D-96 for diluted one-shot use -- and I don't use Xtol that way, and never have used D-96 (because at still film contrast levels, it's not advantageous over D-76 or Xtol, again IMO).

 

[Adrian Bacon]

I wouldn't worry about 60ml in 2.5 litres. Eventually, it'll work its way out.

+1

60ml in 2500ml is 2.4 percent. I doubt it’s enough to even make a measurable difference, much less one you’ll see.

 

[Rowreidr]

I've done about 8 rolls since then, and can't tell the difference. I'm just going to keep going on with my Xtol-R*

 

[Andrew O'Neill]

Great! It's probably worked its way out by now.

 

[MattKing]

Or it has established a new steady state and is giving you the best results you ever have had, but will never be able to duplicate again if this particular batch ever needs replacing!

 

[Donald Qualls]

There won't be any steady state until replenishment has diluted out the contamination to negligible levels (which seemingly might have been the case from the start). Until then, the amounts of metol and hydroquinone, at least. will taper off on an exponential decay curve. I'm not enough of a mathematician to say what the decay constant is, which is what would be needed to say how much replenishment it would take to reach effectively zero levels of these contaminants.

However, since in this case the contamination does effectively the same thing the "pure" solution would, just at a slightly different rate and response curve, it's entirely reasonable to get this result where you can't see any change. And because the D-96 is vanishing a little with each replenishment, I'm confident there's no need to worry about build-up of development byproducts as would be the case in a low-rate replenishment (as for instance with D-96 and its own replenisher).

 

[MattKing]

Clearly Donald, you missed the emojis at the ends of my post!

 

[Rowreidr]

Xol-R*, because it has a little magic inside.