Dear brother ,,About bleach and fixer recipes: there are recipe for both published in US patent US6649331. Tables 3 and 4 give formulas for very powerful versions and are not exactly cheap, but at least the bleach processes a lot more rolls per liter than C-41 CD. If you want to create cheaper solutions with equal capacity, you could:
- Mix any of the C-41 formulas. There really is not much wiggle room, these are all very similar in composition and capacity, which is 10-15 rolls per liter.
- Mix bleach following the formula from US6649331 Table 3, but dilute it 1+2 or even 1+3 with water, then bring back to pH 4.2 - 4.5. Use the dilute bleach for 6-8 minutesl.
- Follow Ryuji Suzuki's Neutral Rapid Fixer, ideal pH target for C-41 fixer would be 6.5. For some extra performance you can also use Ron Mowrey's Superfix. Use these fixers for 4-5 minutes. Although clearing time with both is much, much shorter, there are very insoluble silver salts created during C-41 development, and fixers take longer than twice clearing time to remove these.
- Don't forget a final rinse! It's important to keep the film long term stable.
Well, God bless you.Do not use CD3 for the C41/C42 process.
PE
Regrettably, the Egyptian government has now tightened its grip on online purchases and has enacted new laws requiring that a person must have a bank account of at least a large amount and must have an account in foreign currency.It would be exceedingly costly to synthesize CD-4 in small scale. I highly recommend you get it from an outside source which ships to Egypt, such as Fototechnik Suvatlar from Germany.
This may be of interest to your chemist friend.Well, God bless you.
Are there any alternative ideas?
- What are the steps to prepare CD4 from scratch?
The equation exists but is not enough, I could not understand how to apply that equation?
What are the conditions for applying and equipping this equation?
4-AMIN0-3 - METHYL-N-ETHYL - N- (BETA-HYDROXYETHYL)
ANILINE SULFATE
- I have a chemist friend specializing in private chemistry and is currently doing graduate studies in special chemistry and industrial chemistry, but he told me that that equation must be available with the method of preparation.
In fact, you are a good and respected people.Rudi, those chemicals and procedures are quite dangerous and some are quite toxic. I would not suggest that an amateur try this.
PE
God bless you, my dear brother ,,This is a bleach which likely works, but one that was not formulated for C-41 process. It may be too strong and may kill some ancient C-41 emulsions, but most modern color negative films will likely be properly bleached by it.
About the "Sodium chloride (not iodized) .... 100ml": most likely that's a printing error and 100 g of that compound are meant. Normal table salt you buy for food&cooking contains some intentionally added iodide in order to prevent some ailments coming from insufficient iodide in our nutrition. If you use iodited table salt for making this bleach, you will form Silver Chloride and some amount of Silver Iodide. In black&white processing this may be an issue (that's why the formula wants non-iodized Sodium Chloride), whereas for your C-41 bleach it really doesn't matter.
PS: lots of C-41 home brewers use a very simple bleach made from Potassium Ferricyanide and Potassium Bromide, both of which used in amounts of 10-30 g/l. C-41 film is not rated for this bleach either, but since so many home brewers use it anyway with no ill effect, there's a very high likelihood it will work for you, too. The Copper Sulfate bleach, on the other hand, hasn't been used by many so far, so you may be on your own with this one. The ingredients for Ferricyanide bleach should be much easier to get than those for Ammonium Ferric EDTA or Ammonium Ferric PDTA type bleaches.
Yes, your point of view is logical.FYI: I have not tried this copper bleach with color materials, but have used copper-based bleaches with both collodion negatives and paper. I find that copper bleaches sometimes give unexpected problems with partial bleaching and solarization effects. It may and should work well in theory, but be ware of unanticipated problems.
As a sidenote: I wonder if the use of sodium chloride could slow down bleaching and if eg potassium bromide would make a better alternative to it.
I apologize I read the name of the article in a sinful manner in the past.@mohmad khatab : if you are unable to get a chemical compound as simple and non-hazardous as Potassium Ferricyanide, how can you get the other ingredients for C-41 color developer? Stuff like Hydroxylamine Sulfate or whatever precursors you need for making CD-4 ?
Is there a chance you confused Potassium Ferricyanide with Potassium Cyanide, which is a completely different compound? Potassium Ferricyanide, the compound you want, has the chemical formula K3Fe(CN)6 and CAS number 13746-66-2.
Since it may take some time for you to get all the correct ingredients for C-41 processing, you could do some experiments in the mean time, so that you are fully up and running once the CD-4 arrives:
Good luck with your experiments! Let us know how you come along!
- Mix a small batch of C-41 CD with CD-3, use it at 40°C instead of 38°C and, for starters, for 4 minutes instead of 3:15. While this will give you imperfect results, you should be able to scan&correct these pics on your computer without problems. And you get to practice with keeping the developer temperature stable during the process.
- Try to establish good bleaching process parameters. Take an old&expired roll, expose it to sunlight and develop it in regular B&W developer (not color developer! ). It should be completely black&opaque after B&W development. Try then to bleach and fix small film clips. Compare density of these test clips against test clips which you did not develop and fixed right away. Compare different bleach bath concentrations and times.
- Since the bleach is not time critical, you should be able to get started with the cheap&dirty version of Potassium Ferricyanide from China. Maybe filter the bleach before using it.
Yes sir, God bless you.Remember that like the copper bleach, when using a ferricyanide bleach for C-41, after the developer and before the bleach you must use a clearing stop bath followed by a wash to prevent oxidation of the developer by the bleach which would result in stained images (this is not required for the standard bleach). Use a 2% acetic acid stop bath with 10 grams per liter of sodium sulfite mixed in for the clearing bath, followed by the wash.
Welcome to the distinguished sir.Also remember that CD3 will work poorly with C41 films.
PE
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