Sourcing Ferric Ammonium EDTA in the US

pentaxuser said:

Are Andrew's ingredients and amounts all that are needed for perfectly satisfactory C41 negatives

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Yes. I've made similar developers. The differences in terms of image quality with official C41 formulas are very small.

pentaxuser said:

2. Does what Andrew refer to as CD-4 come with different names in Europe and the U.K.?

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No, it's referred to the same globally; as CD-4 or CD4. There are two CAS numbers that reflect a small difference, but the functional part of both molecules is the same. Shipping and duties can indeed make the material more expensive. I know of no domestic source in the UK. There are several sources in other parts of the world. They ultimately trace to China.

pentaxuser said:

3. Would Andrew's amounts that he used for one film actually be OK for several films if used again within say a few hours ?

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Yes; how many exactly will be a guess, but the capacity can be assumed to be the same as for commercial developers. This is usually considered to be in the 6-12 rolls per liter range.

Unbuiltbread said:

Would like to make my own RA-4 and C-41 chems (mostly RA-4), but I cannot find a single source for the Ferric Ammonium EDTA anywhere. I’ve searched Artscraft, Photoforumarly, and major chemical suppliers like Flinn, CarolinaBio, and Fishers.

Without making my own, is my only option to use the alternative Ferric EDTA + Tetrasodium EDTA bleach that PE lists, or seeing if a ferricyanide bromide bleach from ECN-2 works?

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It indeed works perfectly for both ECN-2 and C-41 (there is a commercial product which uses it) and allegedly for E-6 (because why shouldn't it)

RPC said:

Following the developer, I have used a 2% acetic acid stop bath with 10 g/l sodium sulfite added to it for a couple of minutes, followed by a wash for a couple of minutes, followed by the ferricyanide bleach with no detectible staining. PE (Photo Engineer) has recommended this acid/sulfite bath many times.

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There are two aspects to Ferricyanide, and both are there because Ferricyanide is a stronger oxidizer than Ferric EDTA:

1. potential staining, if Ferricyanide reacts with carryover CD-4. This is well addressed by your clearing bath.
2. loss of archival stability. Film dyes are attacked by aerial Oxygen, therefore they are typically protected by reducing agents in the emulsion. These stabilizers are potentially destroyed by out of spec bleaches. You negatives/slides will look perfect for a few years, and then fading may set in long before a properly processed negative/slide would fade.

I have no idea, why Ammonium Ferric EDTA is so hard to obtain right now, not even Sigma Aldrich seems to offer it any longer. Artcraft sells all kinds of crazy chems but not this one. Very strange indeed. The good thing is, that the procedure for making it is not that involved, it's certainly easier than mixing all 7 E-6 bathes.