Fixer failure.

[dancqu]

[QUOTES=gbroadbridge]

"That will track pH but what about dissolved silver ...?"

A most important consideration. That is dissolved
silver per unit volume. The amount of chemistry needed
to fix an 8 x 10 is about 6 ml of A. Thio. or 6 grams of
S. Thio. anhydrous.

By Ilford, dissolved fixer per liter maximum for archival
results is 0.5 grams per liter and by Haist 0.2 grams per
liter. Worst case, unexposed paper, that max is 6, 8 x 10s
Ilford or 2, 8 x 10s Haist. The amount of chemistry needed
per liter is 36 ml or 36 grams Ilford, and 12 ml or 12 grams
Haist, per liter.

Those amounts of chemistry in one liter make for
extremely dilute fixers. Using fixer so dilute will produce
archival results with one fix and, as a little arithmetic will
show, makes for great milage. In fact one may expect
as many prints can be put through as one
would using the two bath method.

I shoot for silver levels somewhere twixt Ilford's
and Haist's maximums; 4, 8 x 10s per liter. So, on a
liter basis, 24 ml of A. Thio. or 24 grams of S. Thio.
anhydrous make a liter of fixer. Dan

"Every fixer manufacturer states in their data sheets
acceptable levels for silver, are you testing those levels."

[Marco S.]

I will now use a "clip test" or a few drops of newly purchased Edwal Hypo Check.

Mike,

You can also check after fixing, to be sure, that the bath completely fixed the film.

Marco