4 Year Old PyroCat HD Am I Pushing It ?

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Ian-Barber

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In July 2018 @Ian Grant mixed me up some Pyrocat HD which I placed in a brown bottle.

I have just tested it on a few 35mm frames and it still appears to be working. Do you think I am risking it ?.
Does it just die instantly or does it fade away slowly.
 
Do you know if it was mixed with water of glycol? The latter is known to last a very long time.
 
thronobulax said:
Do you know if it was mixed with water of glycol? The latter is known to last a very long time.
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He only mixed me 500ml of Part A. The Part B I have was mixed with Glycol. Need to ask him when he comes on.
Do you mix A+B with Glycol
 
I mix both with water, but I don't make more than 500ml stock at a time.
 
It's normally only Part A that gets mixed with glycol. Glycol is used to reduce the levels of oxidation from the multiple compounds used.

Part B can be made up with distilled water since it only consists of Potassium Carbonate solution.

I think you should be good to use the 4 year old dev, especially if Ian made Part A with glycol, but a clip test might convince you one way or the other.

Mike
 
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mpirie said:
I think you should be good to use the 4 year old dev, especially if Ian made Part A with glycol, but a clip test might convince you one way or the other.
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For a clip test would you just mix up a + b as normal and drop some film in for a few mins to see how black it goes
 
Yep, exactly.

Get some scrap film, well exposed to light, drop it into the mixed developer, leave it in there for your normal dev time, then fix it and check the density. If it's as dense as you would expect, then your dev is okay, if it's not as dense as you would expect, then ditch the dev and get hold of some fresh.

Mike
 
When I was living in Turkey my Pyrocat HD Part A in the UK lasted just over 4 years in a part filled bottle. The colour will have changed if it has gone off, and be particularly noticeable when mixed.

Ian
 
Ian-Barber said:
Ian, would it go darker or lighter in colour
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Usually, when developers oxidize they go darker, and spent Pyrocat-HD is darker than freshly mixed, so I'd expect it to be darker than usual if it's gone. That said, the only real test is to develop a sheet of film per your usual ASA and development practices.
 
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