Exhausted fixer Ran into a bit of a problem with my fixer, I keep a log on the baths, one for the two bath for fiber prints and one for my RC work prints Using the old Kodak formula of 120 8x10prints per gallon capacity I used 60 8x10s per half gallon . which may or may not be completely wrong. I have been using Ilfords Rapid fix 1:4 when I stared getting some yellow stains on prints that I had done several weeks before. Which to me means exhausted fix, Yet the log showed I had not exceeded the 60 per half gallon and Edwals Hypo chex showed no signs of exhaustion I looked up Ilford data sheet and quite frankly cant figure out what their capacities are using the figures they give,.much less the replenishment rates I guess I am just too old fashion I think in terms of how many 8x10s per gallon. Also does Hypo Chex no longer respond to the new fixers?
The capacity of Kodak Professional Fixer package is stated on the as 100 8” x 10” prints per gallon. I use 2-bath fixing of both prints and films. I use a quart to fix 25 8” x 10” prints (or 2000 square inches). Then I discard fix #1, move fix#2 to the fix #1 bottle, mix fresh fix #2, and repeat every 25 prints or that same surface area equivalent. For films the capacity is 25 rolls or the equivalent surface area whatever the film size. Note: Kodak cautions that the capacity is only 2/3 as much with T-Max films. That works out to 17 rolls per quart. I follow the advice in older Kodak publications to keep film fixer separate from paper fixer. By following these recommendations I’ve never encountered any problems such as you’ve described.
Use a 2 bath method, it takes more fixer to start, but ultimately, you will still consume the same amount. Exhaustion schemes have the problem of averaging - 120 black prints will exhaust far less than 120 white prints, so they have to average. You can get a testing solution (lifetime supply for a few bucks - I have a couple of small Edwal bottles from the 70s). Test the first solution till it starts to show failure, then, as Ian says - dump the #1, move the #2 up to #1, and make new #2. You'll never have underfixing. You can find plenty of opinions on this by searching this forum for "2 bath fixing".
How old was your working solution, Ilford only suggest a bottle life of one month in a half full bottle. Do you use an acid stop bath? If not the ph of your fixer will drift out of spec with developer carry over. Capacity is 40 8x10 fiber prints per liter of working solution. I've found that used working solutions can die rather abruptly in the tray, so I test it before I start printing and when I'm finished. If the Edwal tester shows it dead at the end of the session, I mix up some new stuff and refix every print done in that session.
hi rmolson you can get a good idea on how exhausted your fixer is by doing a clip test... mix a little of the same fixer you are using that you think is exhausted, and see how long it takes your leader to fully clear ... then take another leader of the same film and put it in the fixer you are currently using, and see how long it takes to fully clear ... if it is 2x your fresh fix, it is spent ... edwals hypocheck will give a false read in fixers other than edwals the clip test AND keeping track of what went through your fixer is the best way to know if it is dead or not ... with prints ( and film ) that matter i used to always mix a fresh batch of fixer and re-fix everything anyways if i got "nervous" my fixer died ... and then i realized i was 2 bath fixing so kept up with it ... good luck ! john
I learned a rather unconventional method for testing fixer exhaustion from Per Volquartz last November. Take a sheet of 4X5 unexposed sheet film and cut it into strips. keep them by your fixer storage area and when you want to test fixer strength put one end of the strip in the fixer bath and see how long it takes to clear. If it doesn't clear in less than 30 or 40 seconds, dump the fixer and soup a new batch. I also use the two bath method and keep checking throughout the week to see how well the fixer is clearing the film.
