Still Crazy After All These Years: Revisiting PMK Pyro

[GregY]

No, I'm not familiar with him.

Dario worked at the old Camtech w Peter Jeune & Julian F (who later started the camera store). He had a great exhibition on Harley culture @ Sturgis & was a wonderful portrait photographer....& a killer printer.

 

[Craig]

Hmm, don't remember him. Definitely remember Ian and of course Peter and Julian.

 

[DREW WILEY]

Craig - were you mixing a Pyrocat formula for water or glycol? The water version could exhaust prematurely.

 

[chuckroast]

Craig - were you mixing a Pyrocat formula for water or glycol? The water version could exhaust prematurely.

This.

I had some surprising long term Pcat failure with a water for part A. I have never had any Pcat failure when Part A is mixed in glycol, even well after depleting the original 500ml over a 1 year + .. that is, even a diminishing amount in the bottle with increasing amounts of air made no difference with glycol based Part A.

 

[John Wiegerink]

I've never had a Pyrocat failure with the HDC, MC or HD version, but I only mix in glycol. I have had the HD version in glycol last 6+ years. After 3 of those years I mixed a new batch thinking the old batch could go anytime. I then switched to the new batch, but would test the old batch periodically and it was still good at +6 years when I finally dumped it. Damn good stuff! Yes, it's different than PMK or another pyro I use, WD2H+, but I like it much better overalll. Just me of course and you might have a different idea, which is fine with me.

 

[Raghu Kuvempunagar]

While cleaning the shelves yesterday, I found an unopened bottle of Formulary's PMK Pyro Part A that I had purchased in 2017. Initially I thought of discarding it but did a clip test. To my surprise the leader darkened sufficiently! I still don't know if the developer will work as it should and not sure if I want to experiment with it. But the possibility that PMK Pyro Part A might have survived these many years in the unopened bottle is interesting given how quickly Pyrogallol gets oxidised in solution.

 

[chuckroast]

While cleaning the shelves yesterday, I found an unopened bottle of Formulary's PMK Pyro Part A that I had purchased in 2017. Initially I thought of discarding it but did a clip test. To my surprise the leader darkened sufficiently! I still don't know if the developer will work as it should and not sure if I want to experiment with it. But the possibility that PMK Pyro Part A might have survived these many years in the unopened bottle is interesting given how quickly Pyrogallol gets oxidised in solution.

My experience is that the stuff lasts a looooong time even in partially full bottles. The trick seems to be to store it in glass containers. That seems to make all the difference.

I've generally made it a habit now to put all developer stock in glass regardless of formulation. This prevents air migration one sees from permeable plastic containers.

Even if I mix a gallon of D-76 or DK-50, I store in 2 separate 1/2 gal glass bottles and they seems to have an almost endless lifetime that way.

My local craft brewer sells beer in 1/2 gal brown glass "growler" bottles thereby providing a nice glass of brew and, later, a place for developers

 

[Raghu Kuvempunagar]

Great tip! I will move Part A to a glass container and give it a try one of these days. Thanks.

 

[Raghu Kuvempunagar]

give it a try one of these days.

I developed a short roll of Double X and it worked fine.