All one needs to know about XTOL versus other developers

[Gerald C Koch]

The problem is that METOL and Phenidone both oxidize rapidly and as soon as they are dissolved in water, the clock starts ticking.

I have a test bottle of a highly concentrated MQ developer similar to Rodinal that is over 10 years old. It is stored in a PET bottle and is still fine. So you really cannot make a blanket statement on Metol stability. Phenidone on the other hand is not quite as stable but should last a year in a PQ developer.

 

[miha]

Phenidone on the other hand is not quite as stable but should last a year in a PQ developer.

I always thought it's the other way way aroung.

 

[Chris Livsey]

Seems to me all these photographers with developer storage issues should just get out and shoot more film

 

[Gerald C Koch]

I have Metol that is decades old that is still in excellent condition. However I have had phenidone go bad in only a few months. Once in a developer solution the longevity of both developing agents is similar but Metol still has the edege..

 

[Ian Grant]

I have Metol that is decades old that is still in excellent condition. However I have had phenidone go bad in only a few months. Once in a developer solution the longevity of both developing agents is similar but Metol still has the edege..

Like you I have Metol made in the 18960's or slightly ealier and it's as good as the day it was made. I've Phenidone made in 1961 it's still perfect as well although I'm currently using newer stock. My experience is Phenidone has the edge on Metol once in solution but a lot seems to depend on the source of the Phenidone, Ilford & UK books talk about good storage life while US books say the opposite and my experience matches the UK data

Ian

 

[Zelph]

I would hazard a guess that the previous poster experienced the Fenton reaction and not typical aerial oxidation. So not excluding air was not the problem. The reaction is catalyzed by iron (III) ions. It is this reaction that is blamed for the sudden death of ascorbate developers like Xtol. There is a good description of the reaction in the following article.

http://flipper.diff.org/app/pathways/info/6861

Interesting that it is Iron sensitive. Considering it was initially touted as a Universal developer able to be used in any water, anywhere for great results. Kodak really pushed this as a developer for crappy areas without excellent quality water.

 

[removed account4]

Yes it was airtight in glass bottles. I think the stuff is pure junk when compared with any of the other 6 developers I keep on hand at all times.

i've used it extensively to test it with a variety of films, dilutions exposure and development times and the only reason
i will ever buy xtol isn't to use it as a developer cause i found it to be terribly flat, lacking contrast and density no matter
how much the film was exposed or processed, even as "stock" undiluted ... but to watch the orange liquid disappear.
its like pouring AH dye in a tray into developer and watching it disappear.

useless waste of $$ and time otherwise.

but as usual
YMMV

 

[Sirius Glass]

i've used it extensively to test it with a variety of films, dilutions exposure and development times and the only reason
i will ever buy xtol isn't to use it as a developer cause i found it to be terribly flat, lacking contrast and density no matter
how much the film was exposed or processed, even as "stock" undiluted ... but to watch the orange liquid disappear.
its like pouring AH dye in a tray into developer and watching it disappear.

useless waste of $$ and time otherwise.

but as usual
YMMV

John, you needed to add 10% or 15% more developing time for some reason.



.

 

[PittP]

... xtol isn't to use it as a developer cause i found it to be terribly flat, lacking contrast ...

Seconded. Even had a post on this issue here, and no one could give a hint.
We have high iron (and whatever else) levels in our tap water, and certainly all chemical parameters and dissolved air (some days they pump 50% air through the meter) vary just within the chemical and physical limits of the medium. Using exclusively deionised water for both stock and eventual further dilutions significantly improved consistency (surprise!) and also contrast a bit. TMax 400 however remained a bit flat, just right for grade 17 paper.

 

[Tony Egan]

Gerald, my knowledge of chemistry is far too weak to be able to discern answers from the link you provide but it left me wondering why Jim Noel might have experienced the Fenton reaction in as little as 2 weeks. Is the reaction triggered by certain things or is it time-bounded? I have kept Xtol in winebags for over 18 months, using it as one-shot each time with no noticeable deterioration

My experience also. Been using Xtol for over 15 years. I buy "pure" water in 5 litre wine bags, use the water to mix chemicals and then store the Xtol in the bag. Never skipped a beat using 1:1. The longest period in the bag was about 14 months but I generally use up 5 litres every 2-3 months. My only horror stories have been with pyro developers and the recent TMY backing paper fiasco!

 

[Alan Johnson]

As a postscript let me point out AGAIN that the sudden death syndrome IS NOT DUE TO AERIAL OXIDATION. (I keep using the term Fenton reaction rather than Fenton oxidation for this very reason.) .

This is a rather unusual claim.
The Fenton reaction is not magic, in absence of oxygen something has to be reduced .
All I can think of is that the claim is that sulfite is reduced to bisulfite.To avoid a fall in pH this would need to form some kind of complex with the product of ascorbate oxidation.
If that is not what is claimed it would be helpful to know what what the claim is , not just some magical Fenton occurrence.