Photographers Formulary Pyrocat HD Kit, is This The Correct Color?

[Andre Noble]

Hello,

Today I received from B&H (who had on back order, thus B&H received it ‘fresh’ from PF themselves) a dry Pyrocat HD kit from our friends in Montana. I’ve posted photos of it here.

This powdered Pyrocatechol has the color of a powdered chocolate milk mix (and not the white/pinkish color from my previous experience with same kit long ago).

I tried to call PF to see if this dark brown color is normal, but it’s too late in the day. When I mixed the Part A up in glycol per Sandy King’s directions, the solution is a deep amber color.

My question is: Is this color within normal range for this material? I leave out the possibility of chemical impurities responsible for acceptable batch to batch color variation, if that concept is applicable here. As some of you may be aware, I’ve been jinxed with multiple Pyrocat HD failures in the past, from PF pre-made kits in water.

Please tell me this solution is o.k. Otherwise, please provide a metaphysical explanation as to why the Photo deities continue to frustrate my efforts with this developer?

I have not tried the developer yet to see if it works. My point is, I want fresh developer to start with, and now that it's in glycol, this is especially true. I paid a pretty penny for the kit and glycol seperately ($40).

Thanks in advance.

[Jorge Gasteazoro]

I got mine from Artcraft and it is the same color as yours but in flakes not in granules. Since I dont know if the glycol has any effect in the color ( I mix mine with water) I cant tell you if the solution's color is alright, it looks a bit dark to me, but all in all I think you are ok and should try it.

[Jan Pedersen]

Andre,
Just mixed up a 500ml Pyrocat P kit tonight.
The color of the Pyrocatechol is the same as in your picture and is in granules as Jorge also reports.
Since i have mixed in water the stock solution have a different color as your glycol mix.
By reading different threads on the APUG forum i belive it is fine but will develop a couple of sheets tomorrow night and post the outcome here.

jan

[rcollins23]

I purchased a pound of pyro from PF about 3 months ago and this matches my color-it works fine!

[Andre Noble]

Where's Sandy King (for the definitive viewpoint) when you need him?

Sandy?

[Jan Pedersen]

Just developed a couple of 4X5 sheet film (Efke PL100) in Pyrocat P mixed yesterday and the neg's came out beautifull. Have only made a scan so far but have no doubt that the color it is not an issue. At least in the short term.
Whether there will be storage problems down the road, perhaps Sandy can tell?


jan

[Don Hutton]

"Where's Sandy King (for the definitive viewpoint) when you need him?"

I believe that he is enjoying a break in BC and will be back at the end of the month.

[Andre Noble]

Jan, I too had success with this brown stuff this a.m. Hopefully now that it's in glycol, further oxidation will go very slow.

As for S.K., Let's hope his break is enjoyable, not the same the same kind as our other Pyro expert's (S.S's) recent break ;)

[sanking]

Hello,

My question is: Is this color within normal range for this material? I leave out the possibility of chemical impurities responsible for acceptable batch to batch color variation, if that concept is applicable here. As some of you may be aware, I’ve been jinxed with multiple Pyrocat HD failures in the past, from PF pre-made kits in water.



Hi Andre,

When I was at the Formulary they prepared liquid kits for me of both Pyrocat-HD and Pyrocat-MC in glycol. The color of the -HD kit is a very light amber, the -MC kit is a darker amber, similar to the color of the solution in your example. Both kits were made with the same pyrocatechin so the color of the final solution does not indicate oxidation. Both kits work fine, and given the fact that the glycol will preven any further oxidation, I expect them to both work fine five or ten years from now.

I don't know what to say about the color of the pyrocatechin in powder form. All of the pyrocatechin I have on hand ranges in color from off-white to light beige, and is in the form of small granules. And some of it is over 4-5 years old. However, I have seen it fresh in many different colors (pink, brown and white) and forms (powder, grains and even cake form), so an unusual color or form does not necessarily indicate that it is bad.

Another issue is that the heating of the glycol may produce some coloration from dyes when combined with pyrocaetechin, and/or with phenidone or metol. When I first started mixing Pyrocat-HD in glycol I added the phenidone to the glycol when it was at about 180ºF and there was some immedate coloration toward middle to dark amber. However, the color did not change the working characteristics of the developer. I saw the same color when mixing a solution of Pat Gainer's PC-TEA (which also contains phenidone) and that solution is still working fine about 2.5 years after mixture, even though it is a deep brown color. In any event, if you follow my present directions for mixing Pyrocat-HD in glycol you only need to heat the glycol to about 120º F.

Sandy King

[sanking]

[QUOTE=Andre_941]Hello,

I tried to call PF to see if this dark brown color is normal, but it’s too late in the day. When I mixed the Part A up in glycol per Sandy King’s directions, the solution is a deep amber color.

My question is: Is this color within normal range for this material? I leave out the possibility of chemical impurities responsible for acceptable batch to batch color variation, if that concept is applicable here. As some of you may be aware, I’ve been jinxed with multiple Pyrocat HD failures in the past, from PF pre-made kits in water.

Please tell me this solution is o.k. Otherwise, please provide a metaphysical explanation as to why the Photo deities continue to frustrate my efforts with this developer?

QUOTE]


Hi Andre,

I am mostly into facts, not metaphysics, so I am at somewhat of a loss to explain why the Gods have selected you to experience so many Pyrocat-HD failures. Perhaps a full confession of your sins to a local priest would set you on the right track!!

However, can I assume that you are the same person using the name "Large Formater" asking a similar question on the photonet forum? The image of the container and color of the solution appears too similar to be a coincidence? I started to respond to the question over there but no point IMO in doing so if you and "Large Formater" are one and the same.

Sandy

[Andre Noble]

Thanks for the reassuring reply, Sandy.

BTW, I have 150F as your recommended temp for the Glycol, and 120F as the rcommended temp for the small amount of distilled water for the (2 other powdered ingredients). It's possible my Glycol was a little hotter than 150F as my VWR scientific thermometer has not arrived from EBay yet, so I guestimated by feeling side of pyrex.

Finally, I put original question on phonet before I remembered it's possible to post photos here, yes that's me over there, "Largeformater".

Thanks again.

[sanking]

Thanks for the reassuring reply, Sandy.

BTW, I have 150F as your recommended temp for the Glycol, and 120F as the rcommended temp for the small amount of distilled water for the (2 other powdered ingredients). It's possible my Glycol was a little hotter than 150F as my VWR scientific thermometer has not arrived from EBay yet, so I guestimated by feeling side of pyrex.

Finally, I put original question on phonet before I remembered it's possible to post photos here, yes that's me over there, "Largeformater".

Thanks again.

Hi Andre,

I was still curious about the color of these mixes so today I mixed up a batch of Pyrocat-MC, following Pat Gainer's directions. For this I used pyrocatechin purchased from Artcraft. The pyrocatechin is fairly fresh (3-4 months) and very white. The metol and ascorbic I used was also very fresh.

The color of the final stock solution is fairly clear, with just a bit of yellow coloration. However, when I ran a test to compare it to the Pyrocat-MC from Formulary, which is medium amber in color, results on film were for all practical purposes identical.

About all I can conclude from this is a dark amber color of the stock solution in glycol does not indicate oxidation, as we expect iit would in a water-based stock solution A. And, the iniital color of the pyrocatechin does appear to make a difference in the final color of the stock solution.

I should mention that in mixing the above solution I added the chemicals to the glycol at low temperature, and gradually increased it for mixing, instead of adding the chemicals to a very hot glycol solution. This direction does appear to minimize coloration.

Sandy

[Andre Noble]

O.K. Thanks Sandy for the additional tip on mixing temp for the Pyrpcatechol in glycol.

BTW, it makes sense to me too that the brown solution color above is in keeping with the color of the powder. In other words, I didn't really see a darkening. The stuff was brownish, the solution was brownish, and perhaps not quite as dark brown as the exposure in the photo indicates.

I'll have a chance to more thororughly use it but I'm confident it will continue to work properly.

[sanking]

O.K. Thanks Sandy for the additional tip on mixing temp for the Pyrpcatechol in glycol.

BTW, it makes sense to me too that the brown solution color above is in keeping with the color of the powder. In other words, I didn't really see a darkening. The stuff was brownish, the solution was brownish, and perhaps not quite as dark brown as the exposure in the photo indicates.

I'll have a chance to more thororughly use it but I'm confident it will continue to work properly.

André,

It does appear to me that the color of the powder influences the color of the solution, but my experience to this point suggests that the mixing temperature plays an even greater role. I have mixed four batches (with the same chemicals) of this stuff up so far, each with the glycol at a different temperature, ranging from 125º F to about 250ºF. As the mixing temperature is increased the color of the solutions darkens. The solution mixed at 100º F is almost perfectly clear, at 150º F the solution is light yellow, and at 250º F a medium amber color.

Yet all three solutions work the same. I believe there is something in the glycol reacting to the heat rather then the reducer chemicals, otherwise I would expect some slight difference in results.

Another thing you migtt want to note for future reference is that the color of some solutions mixed in glycol appears to darken with age. For example, a liter solution of PC-TEA that I mixed in glycol about 2.5 years agos is quite a bit darker today than it was when I first mixed it. Right after I first mixed it the solution was a very light amber, today it is quite dark, a bit darker than tea. But it still works the same.

Sandy

[Jay DeFehr]

I believe there is something in the glycol reacting to the heat rather then the reducer chemicals, otherwise I would expect some slight difference in results.

The amount of oxidized reducer necessary to color a solution is miniscule, and far less than necesary to affect the working properties of the solution.


......a liter solution of PC-TEA that I mixed in glycol....

If it's mixed in glycol, it isn't PC-TEA, it's PC-glycol. TEA solutions darken much more than glycol solutions do.

Jay