Just a few observations:
I transfer prints directly from a rapid fix mixed "paper strength" or 1+9 (Ilford Hypam or Rapid Fix, or Kodak Rapid Fix without hardener) to the selenium toner. No problems with staining, etc. The fixer is neutral enough to not need an intermediate rinse. My point here is that mixing your own fixer might be overkill and not get you any better results at the expense of wasted time.
I use two-bath fixing. Capacity is ca. 40 8x10 per liter. Richard might find it worth it to cut his capacity by 75% for convenience sake, but I do not. The total fixing time remains the same anyway. I really cannot understand the objection to two-bath fixing unless it is the space issue. Maybe there are better ways to deal with not having enough tray space than risking the permanence of your prints or wasting 75% of your fixer. Tray stackers are a pretty good solution and I've used these often for larger prints. Normally however, I solve the space problem by separating the toning from the printing (see below).
A wash aid is not going to increase the capacity of any fixer. It will speed up washing but it won't chemically change any insoluble silver thiosulfate compounds. You need adequate fixing in fresh fixer to achieve complete fixing. If you want to use single bath fixing and still have optimum permanence, Richard's ten 8x10s per liter is the correct capacity (according to Ilford and others). Two-bath fixing gets around the capacity limitation by having a relatively fresh and uncontaminated second bath that finishes fixing the insoluble compounds left by the first bath after its capacity of ten prints has been reached.
The amount of thiosulfate in KRST does not make it a fixer, nor does the toning bath function as a fixer. Plus, if you try to use your toner as a second fixing bath, you'll have to toss it when the fixing capacity is reached, well before the capacity of the toner is reached. Uneconomical and environmentally irresponsible. (Do a search for some of my posts on replenishing and reusing selenium toner so you won't ever have to toss it.)
Commercial fixers like the ones I have mentioned are designed to be used with an acid stop bath. Don't mix the stop bath too strong and drain your prints well before transferring them to the fix and you should be fine. Whether you use one or two-bath fixing, the fix won't die from "acid contamination" before you reach its capacity when transferring directly to the fix from the stop. You don't need a water bath between stop and fix at all; it is completely superfluous. Why would you want a process that added yet another step without getting any better results? (plus, you could use the extra space for a second fixer tray...)
Indicator stop baths mixed a bit weaker than recommended (2/3 recommended strength or so) do not have much odor and work just fine; they just have a smaller capacity. Toss the stop when it just begins to turn color.
Neither fix at "print strength" nor a weak stop have a whole lot of "fumes." I notice almost no odor at all except when I mix a fresh stop bath. If you are dealing with a lot of odor, you might need to deal with ventilation problems before trying to find more odorless chemicals.
To optimize your processing space, you might try dividing your work flow and separate the toning session from the printing. I develop, stop, give fix one, then wash and dry prints. The toning session is a water soak, fix two, toner, hypo-clear and wash. Doing all that stuff at once is just to much and takes too much room. Plus, I can live with the prints for a while and discard the prints that I don't think will make the grade before toning. This keeps me from spending a lot of toning time on reject prints.
Just some ideas...
Last edited by Doremus Scudder; 03-13-2013 at 01:20 PM. Click to view previous post history.