Bruce Watson said:
I'm wondering how hardener in the fixer will effect a film's ability to be washed using the Ilford method - three or four changes of water with continuous agitation - y'all know the one.
I suspect that hardener might effect the ability (or at least the rate) of hypo migration from the emulsion into the wash water. But maybe not.
Can anyone point me to any research that addresses this issue?
It is a two step process, first the fixer needs to get into the emulsion and remove/complex the unexposed silver - hardeners slow this process down. The second step is removing the fixer and residual silver compounds from the emulsion - this is basically a chemical diffusion process.
Several APUG members have tested fixers for fixing speed and post-fix washing characteristics and have reported the results here on APUG. In general, non-hardening fixers that contain ammonium ion fix film very quickly - and film fixed with these non-hardening ammonium ion fixers washes fastest and most efficiently to archival standards. Fixer removal is a diffusion process, thus the fill, soak and dump method is a very efficient washing method.