Pyrocat-PC with p-aminophenol HCL?

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olk

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5.0g of p-aminophenol could be substituded 6.67g p-aminophenol HCL.
But how to deal with/neutralize the HCL? Should I skipp/reduce the ascorbic acid?
 
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olk

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Alan Johnson said:
Without doing the calculation, 1.67g HCL will have no detectable effect on 750g Potassium Carbonate in Part B.
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I'm wondering why Sandy King used the base instead of the hydrochloride (which is more stable).
 

koraks

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olk said:
I'm wondering why Sandy King used the base instead of the hydrochloride (which is more stable).
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Ask him? He's still active and in my experience always willing to share his views.

As to your original question: sounds easy enough to try it out with a small batch. I often mix up something like 50ml of an experimental soup and see how it goes; then maybe scale up if I like it.

Alan Johnson said:
Without doing the calculation, 1.67g HCL will have no detectable effect on 750g Potassium Carbonate in Part B.
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Yup. I also don't expect the HCl to do anything particularly problematic in the part A concentrate.
 
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olk

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I used Propylen Glycol at 50°C. The 6.67g p-aminophenol HCL seamed to be disolved after 30 min stiring (at ca. 52°C). The result is very dark brown solution (not translucent).

 

Alan Johnson

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If you try to make p-aminophenol by reacting paracetamol [acetaminophen, Tylenol] with sodium hydroxide it does go very dark brown very quickly due to oxidation by air [in absence of the antioxidant sodium sulfite]. In the brew pictured there seems to be some oxidation. Also as a rule, inorganic substances like chloride generally don't dissolve much in propylene glycol so look out to see if a precipitate settles out.
btw, methylaminophenol sulfate [metol] does not dissolve in glycol unless the sulfate group is first reacted with TEA.
 
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olk

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The dry p-aminophenol HCL was very dark/black crystals.
 
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olk

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After mixing 1+1+100 I got a light pink solution that changed its colo to dark purple.



 

koraks

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olk said:
After mixing 1+1+100 I got a light pink solution that changed its colo to dark purple.
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If I'm to hazard a guess, that p-aminophenol is as dead as a doornail. The developer may still work because the other components are OK. But you probably could have just as well left the p-aminophenol out.

lamerko said:
Might be a good idea to explore another p-aminophenol free formula…
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Yes, I'd say so. Or just use one of the other Pyrocat formulations that are more straightforward. There's no magic to be expected from this particular version.
 

juan

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The original formula turns purple exactly like that when active. I used it for years. I always looked for the purple color to be sure the developer was good and mixed properly. After use, it turns a very dark reddish purpleish ugly color.
I'd try developing some film in what you have.
 
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olk

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I guess the aminophenol hydrochloride is gone ... the crystals should be gray instead of black?!
The batch is ca. 4 years old (from Photographers Formulary).
In another thread I found the statement from juan: "The PC version doesn't instantly turn purple - I find it turns a bit amber and slowly turns purple over several minutes time.".
Developing a stoufer wedge worked but because I'd like to use it for calibration O need a stable developer so I'm uncertain if the developer is O.K. (not only the catechin is active). Is the deep purple color a good sign?



 
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GLS

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The pure HCl salt should be white to off-white in colour. The material you have is probably still active to a degree, but the colour indicates it is likely significantly oxidised.
 

Tumbles

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I just mixed up a batch of Pyrocat PC. I managed to find some new p-aminophenol which is a pale, slightly pink color. When mixed, the solution looks like red wine. It's still transparent, but you have shine a bright light through the bottle. I still haven't tested it out yet.

A while back I mixed up a batch using some old decomposed p-aminophenol, which was a dark purple/black color. It came out the same sort of red color, except it was almost totally opaque. I used it for around 6 months, and I initially got some pretty good results. Except in a few instances with 120 film and minimal agitation I had some serious mottling problems. Way more than I had seen before with any pyro developer.

When I first started using it, the working solution would gradually turn purple over the course of maybe 4 minutes. Towards the end, it would turn fully purple in like 30 seconds. This is when I started having some serious failures. If it turns purple that quickly, it's probably bad news.

Here's the last thing I developed with it, when it really showed how truly bad it had gone:
 

Bruce Butterfield

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Might be unintentional but I really like the result!
 
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