This is certainly odd. When does it show up, I think you said but I
am too lazy to look at the thread.
One suggestion is to stop using the Ilford method and go back to a
conventional fixing and washing method. It may be the paper will not fix
out completely with minimum time. Ilford recommends up to 5 minutes in
1:4 fixer without hardener for fiber paper. Hypam is acid although of
higher pH than hardening fixers. There is a separate hardener addition
which also lowers the pH. Mostly not needed.
I suggest trying the longer fix, then brief rinse, then KHCA or
similar wash aid for recommended time (three minutes for double weight
fiber) then tone in a separate bath and wash for 20 minutes. Actually,
toning can be done at any point after fixing but KRST and similar toners
can stain if the emulsion is too acid so its best done after a sulfite
wash aid.
It would be a useful experiment to process a print using standard
wash technique but not toned. See if its stained. If it isn't tone it
using diluted toner for protection or more concentrated toner for color
change, then wash as prescribed for the toner. I am not sure another
dose of wash aid is necessary. I think the toner is not acid.
Note that when the emulsion is acid there are conditions in it that
tend to bind both hypo and its reaction products, when it is neutral or
slightly alkaline the same residues are repulsed by the emulsion. This
is one of the main reasons wash aid works.
I don't know why some paper floats when being washed but I have
observed the same thing. I think it has to do with the amount of water
absorbed by both the emulsion and the support, some is just spongier
than others.
There is a data sheet for Hypam on the Ilford web site.
FWIW, even though some think that two bath fixing is not necessary
when using rapid fixer I think it still has an advantage especially if
the fixer is diluted 1:9 to avoid too short fixing times with RC paper.
It can't hurt and is a good precaution against leaving insoluble fixing
reaction products in the emulsion. A sulfite wash aid will release some
of those so is useful even when using a neutral pH processing chain.
On 3/7/2016 6:35 AM, Tim Daneliuk wrote:
On 03/06/2016 08:03 PM, `Richard Knoppow wrote:
Can you describe the stain in more detail. The selenium staining I've seen
was due to decomposition by acid after incomplete washing and was peach
colored. This is the effect that requires treating prints fixed in an acid
fixer with some sort of alkali bath before toning.
If you have not been getting stains before then _something_ must have
changed. I don't have a definite clue but going over your whole routine may
turn something up. Anything new there, newly mixed something or new paper even
if its stuff you have been using?
The stain is a light rose/purple/brown color. It's visible only on the
unexposed portions
of the print, like the borders. Suspiciously, it seems more evident on the edge
that is at the top of the print washer ... more on that below.
My protocol is:
- Dektol for 2 mins
- Acetic acid-based stop for 20-30 sec
- Fix with Hypam using Ilford's recommended 1 min fast fix
- Wash for 5 mins
- Into mix of Kodak Rapid Selenium Toner 1:35 + PermwWash 5-8 mins
- Wash for 5 mins in Oriental archival washers and then hold
When all the prints are done, was the whole lot for 1 hour in the archival
washer.
Things that have changed:
- I switched to Arista.EDU Ultra VC FB several years ago. This paper seems
to tone much more readily than others I have used.
- I note that this paper will not sit inside the print washer, but floats
to the top. So I use a couple of clothespins clamped to a divider and
a slide the print under the tips so that the print remains fully submerged.
P.S. I don't recall if Hypan is an acidic or alkaline fix.
On 3/6/2016 4:46 PM, Tim Daneliuk wrote:
For some time now, I've noticed that the unexposed areas of a print--
show evidence of a what appears to be selenium staining - say on the
borders of the print. I've changed nothing in my chemical formulation
or wash discipline.
Any ideas on what the culprit is here?
Richard Knoppow
dickburk@xxxxxxxxxxxxx
WB6KBL
