Mixing Pyrocat Solution B

[Richard Wasserman]

I seem to be in the minority, and I assume it's due to my water, but I have no problems mixing 100g of Potassium Carbonate in 100ml of water. I use tap water at 21ºC and just dump in the carbonate and stir a bit–I've been doing it that way for several years.

[Ian Grant]

Maybe I missed something but Part B is 750 grams Potassium carbonate in 1 litre of water, that should dissolve easily as the saturation point is is 112 g/l at 20ºC.

Sometimes there's a few obstinate crystals that need warmer water to dissolve quickly but they'd dissolve overnight @ 20º C.

Ian

[El Gringo]

Thanks all for the great replies, the chemicals all turned up today so I should have them mixed sometime tomorrow or Monday. I'll report back when I've developed the first batch of negs.

[Richard Wasserman]

Maybe I missed something but Part B is 750 grams Potassium carbonate in 1 litre of water, that should dissolve easily as the saturation point is is 112 g/l at 20ºC.

Sometimes there's a few obstinate crystals that need warmer water to dissolve quickly but they'd dissolve overnight @ 20º C.

Ian

I believe that originally Sandy KIng specified 1000g/liter, but then changed it to 750g because some people had trouble dissolving more. Whichever is technically correct I have been doing it this way for so long with such great results I see no reason to change now.

[Stoo Batchelor]

Stoo, since our discussion in Cornwall a few days ago I've had to make up a fresh batch of Pyrocat Solution B. I found the bulk (over 95%) of the Potassium Carbonate dissolved easily in water at 18-20° C with plenty of stirring and I just needed some luke warm water (50° C approx) to dissolve the rest.

I used to suffer from air-bells in Turkey with Pyrocat, but I found this was partially due to the water, there are two ways to eliminate the problem, both of which are used in commercial developers. The first is the use of a wetting agent, the second adding EDTA or Sodium Hexametaphosphate (once sold as calgon). Dr Andresen of Agfa wrote about avoiding air-bells in the early 1900's and all the major companies patented compounds to help eliminate them.

My own approach has been to add a very small amount of wetting agent to Part A, this is a few drops and entirely eliminates the air bell problem, but too much will cause foaming so it's a fine balance.

Ian

Ian

I hear you regarding the wetting agent, and I am pretty confident that it would do the trick, either that or a little bit of Isopropyl, but my concerns are mainly with the pin holes. I do find it rather strange that I have never had this problem with any other developer, even Pyrocat HD, and that there is probably many users also using Pyrocat M daily, without issue. It's just one of the many mysteries of photography. I just stood to attention when Patric Gainer suggested a different 'B' bath, the reason being that I feel that the carbonate is probably the cause of the pin holes, after reading between the lines in the cook book, and conversations I have had with both yourself, and others, and if not, at least it is another variable that I have taken out in my process of elimination.

All that said, I am happy with what I am using at the moment and would not wish to return to a developer that causes me issues, as my photographic journeys are too distant and few and far between to be screwing up any more negatives.

I will be happy when I have finished developing my own staining developer

Cheers

Stoo

[Stoo Batchelor]

Thanks all for the great replies, the chemicals all turned up today so I should have them mixed sometime tomorrow or Monday. I'll report back when I've developed the first batch of negs.

Good luck Rhys

I am sure you are gonna love your negs. And if they are a success, I will send you my film to process

Best

Stoo

[El Gringo]

Mixed the Pyrocat yesterday and managed to develop three negs this morning. They're still drying but on first inspection all looks pretty good, especially since I just kinda guessed the dev time (12 1/2 mins for Fomapan 100); weird getting brown negs!

I hope to get some test prints done in the next few days and will post some up when they're done.

Thanks again for all the help.

[sanking]

Solution B of Pyrocat, both -HD and -MC, is a 75% solution of potassium carbonate. This should mix easily as the solubility of potassium carbonate is well above 115% at room temperature. If your solution does not go into solution readily you most likely have something other than potassium carbonate, perhaps sodium carbonate or a mixture of sodium and potassium carbonate.

Any of the problems that I have seen reported over the years from the use of Pyrocat are resolved with the use of distilled, ionized or purified water. Ian has noted other solutions but given the cost of good water this would always been my path to avoid problems, whether with Pyrocat or any other developer.

It should be noted that Pyrocat in normal dilution of 1+1+100 contains less reducer than 99.9% of all formulas. This is one of the reasons for its outstanding acutance with normal agitation, but can be a negative when the working solution is mixed with water of questionable quality.

Sandy King

[Mahler_one]

I have had no problems with mixing Pyrocat HD. Then again, I mix the solutions with purified ( distilled ) water available at a very reasonable price at the Publix markets here in Florida...

[Stoo Batchelor]

I would just like to point out that my previous posts in this thread were made with the understanding that it was still the norm to mix 100g of Potassium Carbonate in 100ml of water, and I was unaware that an adjustment was made to the formula. I still stand by my words in that 100g of Pot Carb is a pig to dilute in 100ml of water, at least that is my experience.

Reading between the lines of Sandy's post, I have always mixed my chemicals with R.O water, not distilled, de-ionized or purified, as mentioned. Perhaps this is an avenue that I should explore. And to end, although this is not my thread, I would like to thank all involved for their input, as even after a long time now mixing my own developers, I am still learning, so thank you.

Best

Stoo