Pyrocat HD Failure Images

[interneg]

Sensitizing a VC emulsion is straight. You simply mix a color blind emulsion, not sensitized, with an ortho emulsion sensitized
during addition with Erythrosin B, then you may add a 3rd ortho Erythrosin emulsion sensitized after addition, which lowers ortho effect to the half...

It can be done with a single low tech dye with great results...

1. What type of emulsion are you making - from the sounds of it, probably not a sufficiently advanced one to be able to get the correct contrast at G5 once blended?
2. How are you preventing crosstalk?
3. How are you preventing dye migration & staining - especially with erythrosine?

[Pere Casals]

1

the light farm


My DIY VC emulsion does not go from G00 to G5, but I guess that I may reach from G1.5 to G3.5 or G4, which will cover a lot of situations for printing on glass, I'm interested on that. Buying Rollei Black Magic it's easier

A grade 5 component is the easiest thing in the word, monodisperse, the difficult thing is a G00, a long digestion provocates fog.

_________

2,3

Using small dye doses and extensive washing before mixing

_________

I'm playing with it and learning, but it looks that it has to be very easy for a manufacturer, layered dye sensitization is not layers of emulsions, but layers of dyes on the crystals, this allows a high flexibility for a manufacturer. I'm learning about that...

[John Layton]

Back to Pyrocat HD...seems like Bostick does not make a glycol version?

[Tim V]

No, seems not. And I’m still unclear as to why or how the PF kits are failing?

Back to Pyrocat HD...seems like Bostick does not make a glycol version?

[agregov]

My theory is the chemistry is old. When I was having my troubles, I found this thread where PF Pyrocat chemistry was allegedly years old after just ordering:

https://www.largeformatphotography.i...=1#post1459698

And then a bit later, the problem was solved with chemistry from Bostick:

https://www.largeformatphotography.i...=1#post1460064

That's when I ordered HD from Bostick and once I saw that the Part A came dry, the light bulb went on. I think it's as simple as PF mixes fairly large batches of wet chemistry and waits until they sell out their inventory before re-mixing. Or if they do have an expire date, maybe they miss taking some inventory out of stock. After I mixed the Bostick (on April 18th), I took a snap of the three chemistries I had on hand (see attached). Far left in the image is Bostick HD Part A (freshly mixed), center is Formulary HD Part A (opened sometime last August) and right is Formulary MC/Glycol Part A (opened sometime in January).



I don't want to sensationalize anything here. The PF HD Part A in the center is likely contaminated or definitely oxidized. The PF MC should work fine given the glycol formula. But my FP4 times using the MC formula were in the 6-12 asa range. That just made no sense. With some research, I tried the Bostick formula and all my problems disappeared.

I've read a zillion Pyrocat threads in the forum over the years and the most common back and forth discussion I see is someone having a problem and about half a dozen folks say "works fine for me." What I just realized I rarely see is from the folks that have zero problems, how they mixed/obtained their chemistry. I've been using Formulary Pyrocat pre-mixed chemistry from day one for years now and for the film I started with, TXT 320, I've never been able to get past 100asa for my "N" times (1:1:100). I never understood how others got far faster times for TXT. Now I think I know. I'll bet there's a decent chance that many who are having Pryocat issues are using Formulary pre-mixed kits (any). Of course I doubt the power based kits have any issues.

Let me reiterate, that I'm a big fan of Formulary and have not been looking to bad mouth them at all. In fact before this thread even started, I tried to reach out to someone there to report my findings. Still haven't heard back from them yet. I just don't want anyone else to go through the pain people like me have had with Pyrocat. Because since moving to using good chemistry, it's been a problem free developer.

[Tim V]

Thanks for the run down. Just so I’m absolutely clear, you think PF dry / powder packs should guarantee a trouble free experience; that the premixed kits may be old / oxidised by the time of sale.
Thanks again,
T

[esearing]

In response to Agregov's link to my earlier postings - After suffering failures from the B&S kits within months even, I have switched to Pyrocat M and am mixing my own with chemistry from Artcraft. 10 for 10 batches so far have come out perfect. For EMA I did have to bump part B a little bit when compared to _HD. For those that don't like semi stand or EMA, a more standard mix of 1A/0.8B/100W for 14 minutes gives a nice contrasty negative with little stain, 2 minutes initial agitation then 10seconds every three minutes, 70 degrees.

My theory of the pyrocat HD failures is :
Quality and Age of the chemistry is unknown to the user. It could fresh, it could be 5 years old.
Phenidone doesn't last or may oxidize in plastic containers.
The EMA dilution for only 500ML may not be sufficient for the Phenidone to act as initial speed developer or it exhausts too quickly. Metol does a better job.
The EMA dilution recommend by Steve Sherman may be fine for higher volumes. So one might consider finding that balance of A+B+W that is a little stronger yet still results in good acutance.

I once read a comment by Sandy King that stated to use glass containers for the Pyrocat formulas to make them last longer. So I am trying that in addition to making smaller batches.

[Tin Can]

Good thread.

Thank you all.

[Corran]

Eric, I'm glad you've gotten your Pyrocat handled.

My theory, is that whatever issue PF had, after Steven brought it up to them and discovered there was a bad batch, they must've threw it all away. My Pyrocat HD in gylcol, ordered right around that time, I specified to please mix it fresh. I got it and have been using it since with zero issues. So perhaps my request spurred them to mix a fresh batch.

I will mention that my first batch of Pyro ever, from PF, was a dry kit. It came with erroneous amounts of chemistry - they had mixed up bags for 1L and 5L in my kit, giving me 5x the needed amounts of some components. Mistakes happen. I have since only bought liquid kits and have been okay, luckily. Perhaps all the issues reported in the last year will help them ascertain their failure point(s) and moving forward everything will be fine? I hope so. I am not really interested in mixing my own from raw chemicals.

[ParkerSmithPhoto]

Far left in the image is Bostick HD Part A (freshly mixed), center is Formulary HD Part A (opened sometime last August) and right is Formulary MC/Glycol Part A (opened sometime in January)... I don't want to sensationalize anything here. The PF HD Part A in the center is likely contaminated or definitely oxidized. The PF MC should work fine given the glycol formula. But my FP4 times using the MC formula were in the 6-12 asa range. That just made no sense. With some research, I tried the Bostick formula and all my problems disappeared.

I think the answer is right in front of us. Those PF kits are clearly oxidized; the "Formulary HD Part A (opened sometime last August)" is now almost a year old, and the "Formulary MC/Glycol Part A (opened sometime in January)" is six months old at the time of your post.

And.... they are both in the original plastic bottles. One thing is for damn sure, any developer in a plastic bottle is going to go off. I've had fresh Dektol turn sludge brown inside 10 days in a full plastic bottle that was supposedly made to hold photo chemicals. Plastic totally sucks in the darkroom.

The catechol (dry powder) from PF came in a plastic jar and it just reeked out my cabinet. I funneled it into a brown glass bottle with a phenolic lid and now can't smell a thing.

I had some troubles with P-HD recently and went off on a puzzler before I realized, duh, the most likely explanation is I made a mistake. And it was my mistake. I have a dilution checklist now so I don't mess it up again.

The two rolls I ran last night are from the getting close to the bottom leftovers of some Jan 2015 Formulary HD glycol mix. This has been in glass bottles for almost the entire time, maybe 2-3 months in the original plastic bottles. I am going to save the last bits of it and then test it every year.