P-Cat HD liquids color

Bruce Osgood

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Attached are picture of the water after a 5 min pre rinse and the P-Cat HD after a 9-1/2 min development.

Do these look right to you? The resulting negative was absolutely blank.
 
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photomc

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Hey Bruce...sorry to hear you are having a problem. From the attached photo looks like you are using Bergger film? Have not used any so can not say if the pre-wash color is correct or not...I know I get a dark blue from Efke, seems like FP4+ is a purple color (but don't quote me on that). The post developer from the Efke I see is usually a pink color, FP4+ is usually close to clear/straw in color.

I'm sure Sandy will reply, and he is much more qualified (as are others), but each time I have gotten clear negs (or very faint image) is either the stock is over 6 months old or it has gotten contaminated. Was this fresh stock? If not how old is it, and did it start out as liquid or did you make it up from fresh chemistry? Tray or tube development?

Sorry for all the questions, but quess the more info we have the closer we can come to maybe finding out what happened. Will watch this one to see what the results are.
 
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Bruce Osgood

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Thanks for the interest Mike,
Yep Bergger. Brand new stock A and B. My Catechol (Pyrocatechol)/Pyrocatechin from PF is a grey color and looks like pieces of chipped slate. I suppose that may be the problem. I don't know what it should look like. I used Glycol in the A solution as instructed by Sandy. I used Sodium Carbonate (A&H) in the B solution, 200 g. Also, it was one neg in 260 mL for 9-1/2 minutes in the Jobo.
But this wouldn't explain the pre-rinse color.
 

Alex Hawley

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Bruce,

Something loks funny to me about the Pyrocat. After development, mine is an aqua blue, lighter in color than the presoak water, but blue just the same. You solution looks more like used ABC pyro to me. That's all I can come up with at this point.

Alex
 

sanking

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Bruce (Camclicker) said:
Alex, I'm sure it is what Sandy call PYROCAT HD.
Click to expand...

Bruce,

1. Totally blank film suggests to me that the working solution was not mixed correctly, i.e. equal parts of Stock A and Stock B. You may have left out either Stock A or Stock B.

2. Also, Pyrocat-HD Stock B is a 75% potassium carbonate solution. If you use a 20% sodium carbonate solution the correct dilution would be 1 Part A + 5 Part B + 94 parts water, not 1:1:100 as when using potassium carbonate.

Sandy
 
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Bruce Osgood

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sanking said:
2. Also, Pyrocat-HD Stock B is a 75% potassium carbonate solution. If you use a 20% sodium carbonate solution the correct dilution would be 1 Part A + 5 Part B + 94 parts water, not 1:1:100 as when using potassium carbonate.
Sandy
Click to expand...

Oh, I missed that little item somewhere along the way. Will try again tomorrow but I'm becoming afraid you're going to ask me to not use your Pyrocat formulas because of all the problems I seem to have.
But again, thank you for taking the time. I guess the blue pre-rinse does not seem out of line to you.
 

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Hi Bruce,

Yeah, Pyrocat is something of an albatross at times.

The blue/green color of the rinse water with this film is perfectly normal. I was surprised, however, that with that amount of oxidation of the developer you did not get any image at all. In my experince a totally blank negative could result from only one of two conditions: 1) the negaative received no exposure, or 2) the working solution did not contain both A and B stock solution.


Sandy




 

gainer

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Bruce (Camclicker) said:
Attached are picture of the water after a 5 min pre rinse and the P-Cat HD after a 9-1/2 min development.
Do these look right to you? The resulting negative was absolutely blank.
Click to expand...
What was the color of the working solution before development?
Try a developing a snip of film in room light to see if the developer is active. It should get quite dark in 2 minutes if 9-1/2 minutes is to do the job.
 

skahde

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Bruce (Camclicker) said:
Do these look right to you?
Click to expand...
"Now that's what I call a dead parrot." Question is why you didn't get even the faintest trace of a picture.

Stefan
 

juan

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Don't bother to mix the B solution. If you're weighing out the sodium carbonate, just weigh it for each batch of working solution. Add the A solution to your water, then take 75% of the amount of A, use that figure to add sodium carbonate measured in grams.

In other words, if you add 10ml of A to the water, add 8g of sodium carbonate (7.5 if your scales are that accurate) to the working solution.

That way, there's very little chance of cross contamination of A and B.

I'm no chemist, so someone may tell me how I'm doing this incorrectly, but it seems to work for me.

juan
 

photomc

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Hello Sandy,
Since I just had a recent post where my 'aged' Pyrocat-HD went off thought I would mention it here as well. The films were Efke PL100, which did give quite a bit of negative (just one could tell that there was something wrong - looked to be about 2 stops off) and the other was Ilford FP4+ - this gave only faint image on some frames, while other frames were blank, clear, nothing. It is difficult to see any image but there is a hint that something is there when under good light. In my darkroom, it does look blank.

As I mentioned in the other post, when I pulled out the stock that had been kept closed (and the bottles were full) it worked fine - in fact used the 'fresh stock' to process 7 more sheets this past weekend and it worked fine. Makes me wonder if the carbonate is what went bad, just thinking out loud.
 

Peter Coats

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I think the problem may be the pyrocatechin......I found a 5 pound jar of pyrocatechin in my local college's photo lab. I was very excited until I opened it - the compound was a brown/grey color. After calling Tri-Ess Sciences and City Chemical Corporation (CCC was the actual supplier), I concluded the pyrocatechin was oxidized. I was told it should be white in color.
I would imagine you got a shipment of oxidized pyrocactechin, although that seems a bit odd coming from PF.
 

sanking

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I am fairly certain that the problem is the weak carbonate Stock B solution. I just tested the pH of a working solution of Pyrocat that should be similar to the working solution used in the thread started, and the amount of carbonate used in the working solution (based on the 20% sodium carbonate Stock B solution) would only bring the pH of the working solution to about 9.7, barely above the threshold for development of pyrocatechin, and well below the pH of 10.9 you would expect from a 1:1:100 dilution using the 75% potassium carbonate Stock B. So in effect I guess it is likely that you would get no image at all with your mix of Stock B, or at best a very faint one.

Of course, all of my remarks assume that people are using fresh chemicals, or at least using the chemicals withing their expected shelf life. Pyrocatechin has very good shelf life, certainly on the order of 2-3 years if stored in tightly sealed glass containers, but if the color is darker than a medium tan its strength would be suspect. Phenidone in dry form has even longer shelf life. I have some in plastic bottle that is at least 10 years old and it works fine. As for the carbonate, my experience is that saturated solutions of both sodium and potassium carbonate, stored in glass containers, alos have shelf life on the order of several years.

Sandy



 
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Bruce Osgood

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Well todays forty into Pyrocat HD did produce a very slight image but not enough to warrant an attempt at printing.

I think, from my experience, Peter Coats may have the answer to my problem in my Pyrocatechin had oxidized. It was not new and has been stored in the original container which housed more air than pyro.

Lesson Learned: Bag volatile dry chemicals in Zip Lock type bag that can be compressed to evacuate air.

I am not able to measure pH levels and Sandy may really be right but using 1:5:100 with Sodium Carb did make an improvement, just not enough by itself.

Juan wrote:
"In other words, if you add 10ml of A to the water, add 8g of sodium carbonate (7.5 if your scales are that accurate) to the working solution. "

This is a good idea but you would need to be making 1000 mL Working Solution in order to use 10mL A I'm making 250mL Working and drawing off from the 1000mL Stock A and 1000mL Stock B.

Thanks everyone, I have to wait until the end of May to order new/fresh Pyrocatechin. Will pick it up again then.
 

gainer

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So make a liter of water with 7.5 grams of carbonate in it and only use 250 ml of it at a time, or even 250 ml period. It's worth a try just to see if it makes a difference.
 

lee

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the stuff I pour out from the pre wash is blue the spent developer I pour out is nearly clear. I will capture all of the liquids tomorrow to see what color it really is.

lee\c
 

juan

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Bruce (Camclicker) said:
This is a good idea but you would need to be making 1000 mL Working Solution in order to use 10mL A I'm making 250mL Working and drawing off from the 1000mL Stock A and 1000mL Stock B.
Click to expand...

It depends on what working strength you're using and how much you're making up. I was pointing out that if you take the amount of A solution you'd normally use measured in ml, then multiply that number by .75, then take product as the number of grams you need of sodium carbonate.

If you're making up 250ml of 1:1:100, you'd use 2.5ml of A and 1.875g of sodium carbonate. If making 250ml of 2:2:100, you'd use 5ml of A and 3.75g of sodium carbonate.

My scales won't measure amounts this small. If yours don't, maybe Gainer's idea is a better one.
juan
 
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Bruce Osgood

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Let me restate what I think is the issue here. Sandy says the Pyro Part A I'm using should be okay. I'm prepared to assume he is correct. That leaves Part B, Sodium Carb in question.

Sandy wrote: "If you use a 20% sodium carbonate solution the correct dilution would be 1 Part A + 5 Part B + 94 parts water, not 1:1:100 as when using potassium carbonate."

To make a compound of 1+5+100 to yield 250mL you would use (A) 2.5 + (B) 12.5 + (C) 185 = 250.

To make a 20% solution of Sod.Carb. wouldn't you use 200g SC to make 1000ml water? I did.

Also, the color of the compounded Working Solution prior to development is clear with just a tint of amber, or wheat or some such name.
 

gainer

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Sounds right, but only if you are using anhydrous sodium carbonate. If you are using monohydrated, you need about 20% more. If you are using true washing soda, there are 10 molecules of water to contend with. If you heat the carbonate you are using you will eventually arrive at anhydrous if you are in doubt. The purest you are likely to get would be to heat baking soda until it loses no more weight. Baking soda from the super market is USP, IIRC.
 

lee

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I am using Arm and Hammer Washing Soda without any problems Patrick. 200g in a liter of water adjusted mix ratio of 1:5:100 or 2:10:100.

lee\c
 

Jeremy

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lee said:
I am using Arm and Hammer Washing Soda without any problems Patrick. 200g in a liter of water adjusted mix ratio of 1:5:100 or 2:10:100.

lee\c
Click to expand...


Ditto. Much cheaper than potassium carbonate (I think I paid $1.97/4 lbs)
 

gainer

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The washing soda I got years ago came in a blue box and was available in any grocery store. It was used for cleaning auto radiators, etc. I used it in developers and in the activator solution for stabilization process. The stuff called "washing soda" in the CRC handbook is Na2CO3.10H2O. I can't even get it here in rural WV now. I don't know what A&H are calling washing soda, but I suspect it might be anywhere in between the anhydrous and the true washing soda. I have heard that whatever you start with, it eventually ends up as the monohydrate if you leave it exposed so moisture can get in or out.
 

gainer

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I should add that if you make a saturated solution, it won't make a hill of beans difference what you start with, but it might be quicker to make if you use hot water. True washing soda thinks it has all the water it needs and is thus harder to dissolve.
 
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Bruce Osgood

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Pat,
A&H All Natural SUPER WASHING SODA (As stated on the label), contains sodium carbonate. I know it may not be ALL it contains but someone on APUG or Pure Silver contacted them and was told it is Monohydrate Sodium Carbonate. There are no perfumes, preservatives or other additives, fragrances or phosphates. Just Mono Sodium Carb. No where on the box does it suggest using it to clean radiators. It is in a yellow box now and bought in the super market.
 
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