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Pawlowski6132
11-Jan-2016, 17:55
So, mixed up a batch of pre-measured ABC Pyro in kit form originally bought from Photo Formulary.

Got 6 clear negatives.

I didn't realize this was a possible side-effect of old chemicals.

Sux

jrp

LabRat
11-Jan-2016, 19:36
Was the kit old stock??? Did you buy it awhile ago??? I would contact them about it... Some of the chems they have sold over time don't have ideal packaging...

I remember reading somewhere Pyro gets old... And I have tried mixing ABC from some 50's (?) Ansco Pyro (in a glass bottle) and got almost no image, very uneven excessive staining, and anywhere even a tiny drop hit, a very difficult to remove "blood" stain appeared...

I barely remember something about the color of the pyro being an indicator of it's oxidation while in a dry state... (Mine was very dark brick brown/red...)

(Someone can chime in on this...)

Steve K

Michael R
11-Jan-2016, 19:44
Yes, fresh pyrogallol is white powder. Sometimes in kits I have seen it heavily caked into hard "rocks", but the colour is the best marker. The darker it is, the more oxidation has taken place.

vinny
11-Jan-2016, 19:55
did it turn tea colored when mixed?

j.e.simmons
11-Jan-2016, 20:20
Michael A. Smith once said his pyro was nearly 100-years old. Do you have more so you can dunk a strip of film in the light to see if it develops?

angusparker
11-Jan-2016, 21:44
Glycol versions of Pyro seem to me to be the way to go - much easier to use and safer than powder mixes. It's pretty damn cheap too versus alternative.

John Layton
12-Jan-2016, 06:07
I purchased three lbs. of "laboratory grade" pyro powder about thirty years ago from a medical school supply house...for $8.00 - as an "outdated" special. To this day what remains of this remains white and viable. Maybe its being "laboratory grade" makes a difference?

I'd tend to worry more about purchasing pre-mixed liquid solutions (less of a worry if in Glycol) - especially in cases of slow turnover of existing retail stocks. I've had great luck with Formulary Pyrocat-HD, pre-mixed in Glycol - even without transferring to the recommended amber glass bottles. Then again, I do tend to go through the stuff fairly rapidly - about 1000 ml of concentrate (A+B total) every three months or so. But I did find a couple of small (partially filled) bottles that went back a couple of years - which tested out fine.

At any rate...I'd chime in with others to recommend caution with some of the more obscure (equals slow retail turnover?) formulations in cases where these are pre-mixed, especially in cases where these are being re-sold (as in Formulary mixes being sold from other suppliers) - not just for possible issues relating to "use-by" dates, but also due to variables relating to handling/shipping/storing (the less of these the better!).

Bottom line...if any "white" powder (or "clear" liquid) ships to you as deep yellow or brown - send it back!

seezee
12-Jan-2016, 07:56
I've had great luck with Formulary Pyrocat-HD, pre-mixed in Glycol - even without transferring to the recommended amber glass bottles.

I was unaware this was a recommendation. Duly noted. Also, I just happen to have taken possession of a case of 16oz. amber Boston rounds yesterday. Yay, me!

Kirk Gittings
12-Jan-2016, 12:12
I got those results with Pyrocat once from PF. I was convinced it was a problem with the chemicals and raised hell-screamed bloody murder to all that would listen...........but it turned out that in a daze I had mistakenly added a 0 to the dilution.........................

Drew Wiley
12-Jan-2016, 12:21
I use PMK, no glycol needed, and it works perfectly even when the bottle of concentrate per se has been 98% air for months on end. But I've never tried ABC.
I have had pyrocat (not pyrogallol) formulas go bad somewhat prematurely in water.

Randy Moe
12-Jan-2016, 12:26
I got those results with Pyrocat once from PF. I was convinced it was a problem with the chemicals and raised hell-creamed bloody murder to all that would listen...........but it turned out that in a daze I had mistakenly added a 0 to the dilution.........................

Ah, an honest man is hard to find.

Very cool Kirk!

Jim Noel
12-Jan-2016, 14:25
I keep quite a variety of pyro developers on hand, all mixed from reagents. One of my bottles of pyrocatechol was purchased in the 1950's, just before I purchased the pyrocatechin. At most they have become slightly gray in color, but their activity is as good as ever. Everything is stored in glass, in the dark in a climate controlled situation where the temperature stays between 65 and 75 deg. F. My mixed up developers don't have to last very long because I use a lot.