I should know this, but I don't. Can a hardener be added to an alkaline fix? If so, is there any additional info I should know, in particular, the type of hardener? I've never had the need to use hardener before, but I am about to process some Efke film, which is known to be very delicate.
I should know this, but I don't. Can a hardener be added to an alkaline fix? If so, is there any additional info I should know, in particular, the type of hardener? I've never had the need to use hardener before, but I am about to process some Efke film, which is known to be very delicate.
Yes, you can add hardener to an alkaline fixer, but hardener is not needed with most films - including Efke film. With Efke film, it is best to learn how to handle the film without damaging it. Once you have damaged the emulsion, it is too late for hardener to help.
I use a lot of Efke film (both sheet film and rollfilm)and have no problems with emulsion damage. I use an alkaline fixer with no hardener. I do use developers that tan the emulsion (Pyrocat) - - however, tanning will not heal a damaged emulsion.
Why limit your self with alkaline fixer? That being said, hardener in the fixer is a waste of money unless you are machine processing with a roller transport processor.
I would add between 1 ml and 10 ml of 37% formalin solution to 1 liter of a sodium thiosulfate fixer at pH 9. I would not add it to an ammonium hypo fixer, as it can react with ammonium ion. It is usable, but reduces the lifetime of the fixer and lowers hardening. I couldn't guess the level to add in that case.
Pyrocat works very well indeed with Efke 25. I rate Efke 25 at an Effective Film Speed of 25. I presoak in 21C water for 2 to 5 minutes and develop Semi-Stand for 16 minutes at 21 C in the 1+1+100 dilution of Pyrocat. I use a water rinse (no stop bath) and fix in a non-hardening alkaline fixer.
Another possibility is to harden the film after processing. As long as you keep the film on the reel, you shouldn't have any problems. I often use a formalin stabilizer bath after washing my black and white films. It's convenient (for the PhotoFlo), but it also does some hardening. Using SH-1 or SH-5 after a good rinse after the fix should work fine.
I remember that Ansco used to use a chrome alum hardening bath after the first developer (as a stop) to harden the emulsion of those old films before it went into the other processes for their Anscochrome color films.
The limits that I find with alkaline fixers are just mine.
1. they are much more expensive
2. less readily available
3. cannot use standard hardeners, if you want to use hardener
4. they are no more effective than acid fixers
5. any percieved advantages are anicdotal
6. while they may or may not require hypo clear to wash they do require an acid stop bath so I see no advantage
I'm sure there are some more but it then becomes over kill. This is just my opinion, so if you are happy, be happy.