C-41 RA Bleach Formula Acetic acid substitution

[Nicholas Lindan]

yes, i use vinegar ... anything over 10% is controlled and i will be using 8% for my formulas

It is things like this that make me look forward to shrugging this mortal coil.

 

[kyuut]

Wow! In this case you should seriously look at replenishing instead of using&discarding. This will require some experimentation, but probably save a lot of money down the road.



Wow, I really forgot to put that number 40ml in my formula. it should read:

water 700 ml
PDTA 34g
FeCl3 40% w/w solution 40g
Acetic Acid 80% 40ml
NH4Br 40g

Water ---> 1000ml, pH adjust with NH3 ---> 4.2

@koraks can I ask you to fix that formula in my ancient posting?

returning to this, i was finalizing my shopping list to make your version for the time being. i hadn't realized before that i can't source a NH3 solution.

my research tells me (NH4)HCO3 would decompose into NH3 and CO2 when heated or in contact with the acetic acid, would that be a good substitute while still having a source of NH3?

the only other ammonia option i found would be drug store ammonia at 6% but i'm still trying to find one that doesn't contain other components

 

[lamerko]

Of course, ammonia is actually a gas, so it's perfectly normal that you can't obtain it in that form. What you need is a hydrate - aqueous ammonia at a certain concentration. Here, 25% can be freely purchased from specialized stores, but the most accessible is 10%, which is available in any pharmacy. I'm convinced that 10% should also be available where you are.

 

[kyuut]

Of course, ammonia is actually a gas, so it's perfectly normal that you can't obtain it in that form. What you need is a hydrate - aqueous ammonia at a certain concentration. Here, 25% can be freely purchased from specialized stores, but the most accessible is 10%, which is available in any pharmacy. I'm convinced that 10% should also be available where you are.

Yeah, ammonia solutions are controlled by the police just as 10%+ acetic acid. the highest i could possibly source would be 5,6-6% from the drug store, just need to check if i can find any that is just water and ammonia. if i can't it seems making it from Ammonium bicarbonate would be the better choice

 

[originalwinslow]

@kyuut I am doing something similar. I have been using ferri bleach for a couple years now and have run about 1,000 rolls through that process but am getting tired of the extra time spent washing/toxicity/clearing bath plus the chance for staining. Shipping official chems here is prohibitively expensive due to hazard restrictions. I want to mix my own C-41 bleach but so far cannot source PDTA in the US. Replenishment would be the only way to keep the cost reasonable at scale with these DIY formulas. 50g of ammonium bromide alone is $15, whereas I can mix ferri bleach for under $3/liter.

What I mean to say is...god speed. You've inspired me to start looking into this again.