ILFOCHROME HOME-BREWED BLEACH
I’m a newbie on this site, but I’ve followed most of the threads on the dye bleach process for a while. As an organic chemist, I actually view the color darkroom as a laboratory, which can give me an artistic-emotional rush after each “experiment”. I think we are all aware of the convoluted, frustrating mess that Ilfochrome marketing has been over the last few years. We also know that the bleach step, and its precise chemistry has been shrouded in mystery for years. It is also obvious that it is this chemistry that provides all of the value-added for the process…and it is what you are actually paying for, big time. Currently, B&H is backordered on the P30 kits, while Freestyle can still drop-ship….with a $40 ship and hazmat fee added on top of the $100 for just two liters.
So, I have now come up with a chemical synthesis of the active dye-bleach catalyst used in all modern formulae….Quinoxaline 7K (see all online MSDS’s for bleach components).
I have also used e-bay extensively to buy “old” P30 kits, although exact ages cannot be determined. Without exception, part A of the bleach exhibits dramtatic decomposition wherein the solution turns dark greenish brown, while dark flock or tar separates. This problem is due to acid-induced decomposition of the active dye bleach catalyst. Additionally, the acid itself, in liquid formulation, is perhaps the main reason for the shipping restrictions. Chemically, you would have to be an idiot to formulate the kit in this manner, unless you desired planned obsolescence in time. To be fair, the larger volume (P3.20) and other roller transport formulations do not use this approach…. But, the acid used does indeed change to the cheaper sulfuric acid. So with the P30 kit formulation, only the little guy will have to worry about how long the item has been on the shelf.
My approach is to use standard battery acid as the basis for a formulation. This is available locally, and over the counter and in convenient volumes at auto parts stores. In addition it is advisable in my mind to attempt to create more dilute bleach solutions which are safer and greener. However in this case, the process flow must be modified to include a bleach-fix step. Process time does not matter to me. My experimentation so far has been limited, and has been done only with outdated CLM.1K on the RC, non-deluxe, base.
If you were able to gain access to the catalyst and the contrast control agent for Ilfochrome, you would also need to be able to answer, in the affirmative, the following questions:
1) Can you mix a B&W low-contrast DIVIDED developer system as has often been described?
2) Do you routinely use RA-4 blix (or Ferricyanide and non-hardening liquid fix conc.)?
3) Can you locally purchase specific gravity 1.265 sulfuric acid for batteries?
4) Can you easily go on e-bay to obtain a few additional, moderately-priced components?
5) Do you have the ability to store used part-B of the divided developer to neutralize bleach?
6) Have you got odds and ends around the house such as NaOH and non-natural vitamin C?
I would like to gage the level of interest that other artist-craftsmen-teckies might have in attempting to formulate home-brewed Ilfochrome solutions. Respond to the post if you are desirous of pursuing such a project. I will respond back occasionally over the next few weeks, waiting to accumulate a list of candidates. Remember however that I can't give you anything on a silver platter....work and patience will still be required.