Old Pyrocat MC with glycol, turned blackish-brown

Hi All,

Before reading this, I know the obvious answer is, "Well... try it", but I'm wondering if anyone has already experienced this and can give me a few tips and some hope:

Several years ago I received some Pyrocat MC with Glycol from Photographers Formulary and promptly put it away under the darkroom sink (where it's cool and dark), to test the following weekend. As this region of my darkroom is known as "The Bermuda Triangle Corner", the stuff was never to be seen again. True to form, I'd forgotten about it until last week when I noticed some blackish-brown crud on the floor around those bottles. It turned out that the bottles of solution "A" were leaking at the bottom (I guess the plastic had cracked over time). I donned my hazardous waste garb and duly cleaned it up, and then re-bottled the remaining liquid in better bottles. Now I'm eager to (finally) use it up or dump it (responsibly .... in the Seine). (Yes, I'm joking).

To my mind the "B" solution is probably still OK because there's not much in it to oxidize. My question to you, oh wise multitude, is: Do you think the "A" juice is still good? I suspect —I mean, I'm hopeful— that because the "A" and "B" solutions were never mixed together, there may be a chance that the developer may still be viable. Hopefully I'll end up developing a successful test roll and screaming, like Dr. Frankenstein, "It lives! It lives!"

Thanks for any insights you can provide, y'all.

IMO, for best results . . . . Mix fresh, right before use!! ONLY thru consistency can you find what works and what doesn't! what you like and what you don't like. If for example, in this case, you use it! and you love the results. You use up the whole bottle with new film exposures, but when you make a new patch, something is different in your results!! now what!! how do you reduplicate the oxidation process, and the "punky" off color of the developer in the bottle.

It might be ok. you might get the same results as "fresh" but again you might not!!! but why risk it????????????

I've had some mc go funky on me. The metol is probably dead....but the catechol is probably fine. So it should develop with much longer development times.

Sent from my Nexus 5 using Tapatalk

xx

Pyrocat MC, HC etc can keep well (4 years in water) but not in poor quality bottles and it's no different in poor bottles with Glycol. I've seen multiple posts of PF chemistry going off early. A UK supplier of Pyrocat sold as Precyscol has similar aging issues due to low grade bottles.

Ian

I have never gotten to this point with pyro, however Per Volquartz told me about that phenomena and he said that the developer turning dark was not a problem and that pyro lasts a long time.

I'd pitch it. Get some fresh solutions and enjoy. I like the developer.

I don't believe the ascorbic acid works well enough as a preservative for Metol, by itself. When I use sodium bisulfite in a water based solution, it lasts much longer in the same bottle. Losing 50g of catechol with PyrocatMC was enough for me. It's both expensive and hard to get here.

My experience with Pyrocat HD in water was that it was fine for a long time until you got the solution levels down to a certain level and there was more air in the bottle than solution. It then oxidized very rapidly without giving an obvious color change to the solution, and you would literally do one developing session and have perfectly fine negatives, then the next batch a week later would look four stops underexposed. Pyrocat is not Rodinal - when Rodinal turns black and tarry it still works. When Pyrocat is oxidized, it's dead. If you want to test it out on some film that doesn't count, go ahead but I would be highly skeptical of the performance. Better off chucking it out and getting fresh that you know works - it's not like Pyrocat is as expensive as gold toner.

There was a thread on this a while back, the recommendation was to store pyrocat in glass containers to prevent or minimize oxidation, apparently plastic containers (at least the ones used by Photographers Formulary) don't prevent oxidation as well.

Yes, glass is definitely the way to go for storage and if you can mix the -MC yourself without the water. I think the Formulary mixes the -MC version with TEA and water. There are instructions somewhere here if you search. You take 100ml of glycerin and heat it up to 200/250F and mix in the 4g of metol and 4g Ascorbic. Then let it cool and mix in the 50g catechol. The catechol doesn't need any heat, you can put it into glycol and mix it up once a day for about 5 or 7days.

I did the glycerin version when I made mine. I just don't see why. I mix metol and ascorbic acid into glycol with other concoctions (it just needs to be slightly warmed).

My ultimate mistake was making a full litre. I should have stuck with making 100ml batches that would have had a chance to get used before bad things happened.

mrred said:

I did the glycerin version when I made mine. I just don't see why. I mix metol and ascorbic acid into glycol with other concoctions (it just needs to be slightly warmed).

My ultimate mistake was making a full litre. I should have stuck with making 100ml batches that would have had a chance to get used before bad things happened.

Click to expand...

I mix small batches only. Each batch is for one shot processing.

Can ingredients like catechol or metol go bad? Or is particular handling needed to store them?

Lars

LarsAC said:

Can ingredients like catechol or metol go bad? Or is particular handling needed to store them?

Lars

Click to expand...

Pyrocatechin can oxidise during storage but it takes some time for it to go off, Metol keeps far better 30 yearsr more. If the Pyrocatechin has oxidised they solution will be greenish blue.

Ian

Great and serious thanks to all of you. I really appreciate the feedback because —not demeaning the advice to "chuck it"*— it gives me enough courage to at least test it first. The "reward" for your advice will be that I'll use myself a guinea pig to obtain the ultimate answer and post the results to share with you (and future readers with the same problem).

*In reply to FlyingCamera: What you say is true, but by the time I replace six liters of this stuff and have it shipped to Europe, it's no longer as "cheap" as it may be in the States. Therefore, if the Pyrocat is still good, I'll keep the stuff to play with on experimental projects.

Thanks again, to all!

PS to Ian: Are you in Paris?? Sorry, too lazy to PM you ..It's an overcast Sunday and I'm off to make banana bread!

Christopher