AMMONIUM CHLORIDE

[relistan]

Regular E-6 bleach contains Ammonium Ferric EDTA and either Ammonium Bromide or Potassium Bromide, so obviously the Ammonium does not hurt. It also does not hurt, if some of the silver gets dissolved in the bleach, in fact PE once mentioned, that the best bleaches are weak BLIXes.

In those processes that makes sense, because you are going to clear out all the silver at the end anyway. I was trying to think about a B&W reversal use where maybe with enough ammonia and ammonium chloride, you could use a single bath and the rehalogenation to silver chloride and dissolution in ammonia would happen at the same time. You'd not want it to clear out the silver bromide and iodide, though, so if it's too strong a general fixer that wouldn't work.

 

[Rudeofus]

In those processes that makes sense, because you are going to clear out all the silver at the end anyway. I was trying to think about a B&W reversal use where maybe with enough ammonia and ammonium chloride, you could use a single bath and the rehalogenation to silver chloride and dissolution in ammonia would happen at the same time. You'd not want it to clear out the silver bromide and iodide, though, so if it's too strong a general fixer that wouldn't work.

That's correct, but AFAIK Ammonia can dissolve Silver Bromide in all but trace amounts, so Murray's bleach may even work as B&W reversal bleach.

My main concern about Murray's bleach was, that it might be very slow, therefore my question.

 

[Murray Kelly]

I agree, Rudi, as PE said several times the Na salt is slower and that prompted me to adapt the BJP bleach with the ammonium ion. I know zero about E-6
I cleared a developed leader in less than 2 min and it was indeed cleared as well. I am somewhat distrustful in nature so give C-41 7 min. Not the best, I know, but I'm in no hurry.
Thanks again for the comments.

Now it is hard to get FeCl3 to etch copper off PCB material and wonder if it would substitute as an etchant.

 

[Raghu Kuvempunagar]

I cleared a developed leader in less than 2 min and it was indeed cleared as well. I am somewhat distrustful in nature so give C-41 7 min. Not the best, I know, but I'm in no hurry.

@Murray Kelly: your adaptation of the Ferric EDTA bleach is very interesting. I should try it one of these days. What is the temperature you recommend for bleaching?

 

[Murray Kelly]

Raghu, I work at 30C but correct me if I suggest that after the developer and wash anyting down to 25C will work.

 

[relistan]

@Murray Kelly: your adaptation of the Ferric EDTA bleach is very interesting. I should try it one of these days. What is the temperature you recommend for bleaching?

I was thinking the same thing

 

[Raghu Kuvempunagar]

Raghu, I work at 30C but correct me if I suggest that after the developer and wash anyting down to 25C will work.

Thanks! I've had good results with ferricyanide bleach (Kodak SR-29) in C41 processing but always worried about dye stability. Your ferric EDTa + ammonium chloride bleach might put my worries to rest. Bookmarked your earlier post detailing the formula.

 

[Rudeofus]

Thanks! I've had good results with ferricyanide bleach (Kodak SR-29) in C41 processing but always worried about dye stability. Your ferric EDTa + ammonium chloride bleach might put my worries to rest. Bookmarked your earlier post detailing the formula.

It is quite difficult to detect incomplete bleaching with C-41 material due to its orange mask. Make sure you test the bleach with E-6 material, or have a setup ready to test for retained silver.

 

[Murray Kelly]

Rudi, do you have any idea the FE EDTA shelf life? I found mine (after several days) at the back of the cupboard, and it won't make a bleach of any sort even tho the last lot I made is still good. It's a bit disappointing.

 

[Raghu Kuvempunagar]

It is quite difficult to detect incomplete bleaching with C-41 material due to its orange mask. Make sure you test the bleach with E-6 material, or have a setup ready to test for retained silver.

Definitely! Thanks.

Rudi, do you have any idea the FE EDTA shelf life? I found mine (after several days) at the back of the cupboard, and it won't make a bleach of any sort even tho the last lot I made is still good. It's a bit disappointing.

Shelf Life is 60 Months at room temperature according to this.

 

[Trask]

Very cool! Will try.

Yeah, give it a go — it works well. If you wiish, post back here with your experiences or PM me; I’d be interested to know what you think of the process.

 

[Trask]

Following up on my own post earlier in this discussion where I suggest adding ammonium chloride to one's developer, I'm posting here as a resource to readers a US patent application granted Eastman Kodak in 1936 wherein EK provides several M-Q-plus-AC formulae. Note the comments about the optimal amount of ammonium chloride. And I think a couple of these are among the older formulae I've seen incorporating triethanolamine.

 

[Tony-S]

What is Ammonium Chloride used for?

In my lab, we use it to deplete red blood cells from spleen cell preps so that all that is left are white blood cells.

No idea about its use in photography!

 

[radiant]

Finns use it in our favorite candy "Salty liquorice".

I use it as salt in alternative processes. I'm tempted to taste the raw powder