shelf life of Pyro

[bernard_wiessner]

In Gordon Hutchings book of Pyro,he states the shelf life of PMK is

10 years.Is this true of other Pyro Developers such as Pyrocat or

WD2D+?

 

Thanks to all

[photojim]

No. DiXactol is said to be good for six to twelve months. PMK is good for at least three years; that's how old mine is. The only other developer that approaches it for longevity (that I know about) is Rodinal.

[ward]

I am just about to use my first ever batch of PMK Pyro and wanted to clarify the question. Do you mean the shelf life of the A and B solutions if kept seperate? Or the powder?

 

I figured the powder would keep until my house crumbled around it. It becomes pretty fragile once you mix the two solutions together, doesn't it?

[bernard_wiessner]

Hi Ward

Sorry about that. Yes I meant the A and B not mixed but kept apart in there own bottles. I think that when the two solutions are mixed they should be used right away. Although Hutchings claims they can sit for about an hour before before use to give the film more stain.

Thanks

[john_stockdale2]

I think that the part A keeps better than the powder pyrogallol. I've got some part A that is several years old and is my "best vintage." I used half a jar of pyrogallol powder to make it up.

 

The remains of that jar of pyrogallol powder went somewhat brown during the ensuing time. I have recently used it to make some more part A and it's a browner colour. It's not staining as well as the older batch. I hope it will come good.

[evan_parker]

Mr. MacKenzie, I also believe that HC-110 has a very long shelf life as well as Rodinal. Good knowledge for those who develop film infrequently (although I am not one of them!). :)

 

Evan

[paul_brenner1]

I've used PMK Pyro since 1992. Due to work demands, I don't do as much b&w as I would like. I've had batches of A & B (not mixed together) for a VERY long time at times and I've never noticed deterioration. Someone once told me that the life was "essentially indefinite" and I would agree with that.

 

Paul

[patrick_mckay]

A sealed-unopened bottle of Rodinal will keep for years, but once open it does begin it's slow inevitable deterioration. This can be noted by the fairly rapid colour shift of the concentrate, after being opened. HC-110, if kept in it's syropy concentrated form, without much air-space in the bottle(s), will stay in top shape for many years. Once HC-110's mixed to "stock solution" strength, it will still last for months, but does have a limited shelf life. Using an infant syringe to extract HC-110 concentrate, per developing session, is a simple way to to utilize one bottle of developer over a very long period of time. I've found that HC-110 gives slightly better speed than Rodinal, but they're both great developers. Have you ever tried your roll-film of choice in Rodinal 1:100 for 15-20 minutes?

 

As for PMK, Mr. Hutchings points out that he keeps a "well-aged" (for years/stoppered brown gallon jug)stock A solution, that he adds in proportion to his fresh Stock A solution. As for the Stock B solution, he notes that it's shelf life is doubtless indefinite.

[john_stockdale2]

One problem with Rodinal is that the accountants at Agfa (and maybe the chemists) have changed the formula at least twice in my photographic time. HC-110 has also changed.

 

When a manufacturer says that "you don't need to worry about that," it reminds me of some of our politicians (sorry if that is OT or impolite, you know what I mean)

[ward]

My experience with Rodinal and HC-110 is that the HC-110 syrup ages MUCH more gracefully than the Rodinal syrup, which turns mucky brown by the time I use up the bottle. Intuitively, I always imagined that the consistency (thick to the point of gloppiness) of the HC-110 makes it more resistent to oxidation. As an explanation it is utter rot, I'm sure, but the HC-110 seems to be almost eternal.

 

Re the Pyro: Postings seem to say that solution A actually ages well, improves with age. I'm intrigued with the idea of mixing a large jug of solution A and keeping it forever, letting it age and using it to sweeten the fresh batches of solution as I go.

 

Does the "cured" solution really behave differently, or are we all just romantics?

[sandy_king]

I recommend that Stock Solutin A of Pyrocat-HD be used within

six months. Stock Solution B should last indefinitely.

 

Sandy King

[photojim]

This is an ancient thread, but I thought it would be interesting to note that my PMK stock solution, which was three years old when I posted in 2003, is now seven years old and still works great.

 

I am, however, almost out of it. :)

 

I have just gotten 100 grams of pyrogallol and have all the other ingredients to mix up my next batch, and I'm confident it will still be good in 2014, at least... if I haven't used it up by then.