Do I need the pre-bleach?

[R Paul]

Well I went out and ordered up some Kodak e-6 chemicals before they vanished. I picked up 1st dev, reversal bath, color dev and fixer. I mix up my own bleach (quinone),so I figured I didn't need the pre-bleach, since that works with the Kodak bleach.
Now am I right in this, and do I rinse between the color dev and the bleach,or go straight through? I also have the starters for the developers,so that's ok

Thanks
Rob

 

[Jim Taylor]

Hmm... from what I understand the pre-bleach is used because the formaldehyde in the stabilizer was switched out due to exposure control regs. Hence stablizer became 'final rinse' (photo-flo and miconazole).

I believe the pre-bleach now contains some chemistry that generates the formaldehyde 'in-situ' and thus is needed for maximum longevity of the resulting chrome.

I guess I'll be corrected if wrong!

 

[R Paul]

I use formalin in the final rinse, so I should be ok. I had forgotten about what it actually did. I am pretty sure PE mentioned it somewhere.
Thanks
Rob

 

[mts]

you should follow both first and second developers with a stop containing both acetic acid and bisulfite, and follow the stop with a rinse to eliminate possibility of contaminating the following solutions, and you must not use the same stop bath for both. That is, you need to have a first and second stop bath.

 

[Rudeofus]

Common E6 bleaches are very benign and, according to patent literature, will speed up if you use a prebleach. There's a good chance that you won't need it with your (much stronger) Quinone bleach, especially if you provide another source of Formalin. Read (there was a url link here which no longer exists) about the purpose of Formalin in E6 processing.

 

[R Paul]

you should follow both first and second developers with a stop containing both acetic acid and bisulfite, and follow the stop with a rinse to eliminate possibility of contaminating the following solutions, and you must not use the same stop bath for both. That is, you need to have a first and second stop bath.

The way I do E6 is from Kodak except I use a quinone bleach ( I think you gave me the formula). It has the 1st dev then a 2min wash with water, reversal bath, color dev,prebleach,bleach,fix ,wash and then stabilizer with formalin. I was thinking of substituting a similar water rinse between the CD and the bleach especially if the prebleach is only taking the place of the formalin rinse at the end. I would like to keep it as simple as possible.
Rob

 

[R Paul]

That would be good. So at worst I would have to extend the time in the bleach. I have had to re-run the bleach and fix steps at times, I think due the bleach aging. I use Photo-flo /formalin mix that PE recommended as the last step. It does pack a punch though especially indoors. I usually hang up the films in the evening and quickly retreat upstairs until the next day.

Rob