Longevity of Metol

[Tim Povlick]

I've done a search (in the forums) about "longevity of Metol" and it seems to turn brown when kaput. I have some that is getting rather old in the tooth (>6 months) stored in small brown glass bottle, still white. Three grams added to 20 oz. of distilled water (with a pinch of Sodium Sulfite) turned a dark tea color. Adding in the rest of the sodium sulfite (D76H was the target developer) the resulting liquid turned black.

Any insight is greatly appreciated.

Thanks,

_ .. --
TiM

[BradS]

Wow. That seems strange. I know that I've had mine (dry Metol) for at least five years....I've never seen that happen. Unfortunately, it does sound like your Metol has oxidized.

[Tim Povlick]

Wow. That seems strange. I know that I've had mine (dry Metol) for at least five years....I've never seen that happen. Unfortunately, it does sound like your Metol has oxidized.

Hi Brad,

Many thanks for your response. After reading this I tried the Metol again and it seems to be good. This is really bizarre as earlier it turned very bad.

I did mix in a different container, maybe that was the problem. The first time, it was also a glass container that I thought was clean.

Strange to say the least but your response was a BIG help.

Thanks.

Tim

[IanG]

I have Metol from the early 1960's that's as good as new Metol. It's from a variety of sources and has names like Elon, Planetol etc ass well as Metol. I also have some Phenidone with a 1962 Ilford code, again works as good as fresh Phenidone.

Ian

[mdarnton]

Mine is from the 90s, and uniformly tan, but works fine.

[rcmartins]

Well, I recently decided to start mixing my own chemicals and thus bought, amongst other chemicals, a relatively large batch of metol. The plastic bag shows a brown powder. Should I be worried? It won't work? I haven't tried it yet.
raul

[imagedowser]

raul, Shoot a test roll and try it. I recommend making D-23, since it's the simplest dev to make with metol i know of, to cut any chance of error, if mixing chemicals for the first time. Get a copy of The Darkroom Cookbook ( by Anchell). Probably avail. through your public library system, or if you can, buy a copy, it's the bible....

[Ken Lee]

Keep it sealed from the open air. Mine came from Artcraft in a small white container with a screw top. It has lasted for several years.

[Michael Cienfuegos]

I agree with Ken Lee, keep it sealed. I have a screw top jar from Kodak (Elon) from the late 1960's. It is still potent, I've used it to mix D76 with no problems.


m

[Tim Povlick]

Thanks Ian, Brad, Ken et. al. for the experts help. I tried mixing D76H again using clean beaker / mixing spoon and steam distilled water. The Metol goes into solution fine and the water is clear. As soon as Sodium Sulfite is added it turns to dark Tea. The more SS, the darker. The Metol was stored in very small brown bottles and both react the same. The SS has run out so I'll order fresh chemicals and try this experiment again.

Raul, Like yourself I recently started mixing chemicals and this sort of problem is a first. I'll report back once new chems arrive (withing 1-week)

Thanks again guys, very good to have this expertise handy.

Tim

[rcmartins]

Thanks Tim.
Meanwhile I went to the site of an international distributor of chemical and bio-chemical products and for the metol they have the following description:
color - white to faintly beige (http://www.sigmaaldrich.com/catalog/product/fluka/69750?lang=pt&region=PT)
Mine is indeed faintly beige.
raul

[Tim Povlick]

well....

The new supplies arrived and I was able to do a quick test. I tried the 'old' Metol with the new Sodium Sulfite. That was it! The new sodium sulfite did not turn the mixture to color of tea but clear.

The 'old' Metol is slightly beige whereas the new is white (not really important). The sodium sulfite looks fine and it is not that old. It was stored in brown glass bottle. I can't be certain but I must have mixed some other chemical in the sodium sulfite thinking I was combining some sodium sulfite from a second bottle to combine quantities.

So the good news is this is resolved, the Metol is good and seems to have long longevity.

Best Regards,
Tim

[Cor]

Although I do have a bit of a chemistry background, I am not a "hard-core" chemist, but I can offer a theory: If your old Sodium Sulfite was not water free (ie hydrated, you could find that information if your old stock has a proper label, something like .7H2O) it will slowly turn into Sodium Sulfate, by itself Sulfate is harmless, but it will not protect against oxidation like Sulfite as well is will not fur fill the other roles of Sulfite.

good luck,

Cor

[Gudmundur Ingolfsson]

I have Metol I bought 41 years ago and it still white and good but it is in a plastic chemical container from MERCK.

[coisasdavida]

Mine is from the 90s too, very tan, good still.