Residual Fixer Tests HT-1 And 2 And

Testing films and papers for thorough washing
has come up on another thread. An interesting
read on the subject can be found at rec.photo
by entering, turner horder . Rec photo is a
Google group.

Take note of Horder's silver nitrate only test
from the Ilford Manual of Photography.
Others require acetic acid.

Turner's potassium permanganate method is
interesting. Should be good for those that tray
wash or can tray test prints.

From Google enter, ilford permanganate test .
More insight there on the washing of RC and FB
papers and films. Dan

dancqu said:

Testing films and papers for thorough washing
has come up on another thread. An interesting
read on the subject can be found at rec.photo
by entering, turner horder . Rec photo is a
Google group.

Take note of Horder's silver nitrate only test
from the Ilford Manual of Photography.
Others require acetic acid.

Turner's potassium permanganate method is
interesting. Should be good for those that tray
wash or can tray test prints.

From Google enter, ilford permanganate test .
More insight there on the washing of RC and FB
papers and films. Dan

Click to expand...

I brought this thread back because the
subjects of hardeners, "Chrome vs ...", and
archival standards have been mentioned. Any
interested in conducting their own tests of
film and RC - FB papers for residual fixer
will find valuable the above mentioned
resources. Dan

Useful References, Dan! Thanks!

I read the Washing Kinematics paper by Rolf Suessbrich several years ago. Rolf used an electrical resistance measurement method to check the wash water for the presence of ions. I already use this method (in my Lab at work) to check the quality of deionized water from my Millipore filter chain. I use 18 Megaohm DIW from this filter chain to wash my film via the Ilford soak and dump method. If the water from the last soak still show high electrical resistance, the "last soak"wash water and thus the film, should be "clean." Of course, this would only be true if
there were no argentothiosulphates bound to (or within)the gelatine.


There is a statement in the Turner Horder reference that expresses my remaining concern: "Tests based on drippings from the negative are considered unsound,
because they do not test for argentothiosulphates bound to the
gelatine."