I think that's backwards, Nick. To reduce the ammonia odor of a rapid fixer, add some acid to bring it to neutral or thereabouts. Acetic acid, sodium bisulfate, sodium metabisulfite, whatever.
Originally Posted by Nick Zentena
OTOH, maybe my brain isn't up to full speed yet, so if I'm wrong, someone let us know.
Perhaps it's time to think about better darkroom ventilation...
BTW, re-reading some of these posts, the most common hardener is alum (aluminum sulfate) which has no odor. It is the increase in acidity in these fixers that make sulfite odor more apparent by releasing more sulfur dioxide gas into the air.
There must be something wrong with me...
I intentionally mix the Kodak F-5 general purpose hardening fixer formula from scratch for film use, even though it's hardening is not actually required. Why? I like the smell. Why? Because it reminds me of younger days in earlier, simpler darkrooms developing films from earlier, simpler cameras. That distinctive smell was my most-anticipated moment when I finished my first new darkroom in 25+ years a while back. And that moment did not disappoint.
(Since I do like to tone in selenium, I mix the F-24 non-hardening version for my fiber prints.)
I know what you mean, Ken. I have lived with fixer smell for over 75% of my life. Nowadays I use Kodak Flexicolor fixer (see above) which smells much less, but I'm pleased to report that my darkroom still smells like a real darkroom. It's just not as overpowering.
Originally Posted by Ken Nadvornick
Among ammonium thiosulphate fixers, the odour varies from ammonia if the fixer is quite alkaline to SO2 if it's acidic. There is a point in between where it smells only faintly of both, and that is where I prefer it. Any spills end up smelling of SO2 but not too strong, so the darkroom still smells correct.
Sponsored Ad. (Subscribers to APUG have the option to remove this ad.)
"Any rapid fixer mixed at film strength will work fine."
Any fixer, rapid or slow, at almost any strength will work fine.
Fresh fixer each roll or rolls is a most sure way to process.
Although I've switched to a 'slow' entirely odorless fixer
derived from a dry concentrate I did for some time use
a liquid rapid fixer. Just about any 120 roll can be
cleared using 20ml of likely any off the shelf
rapid fix; my solution volume 500ml, fixer
1:24. Down the drain when done.
"I do not find any of them totally odourless: "low-odour"
would be a more accurate description I think, but perhaps
I am more sensitive than most people to it. Cheers, Bob."
Perhaps my nose is less sensitive but I believe yourself
and the OP would find a fixer of no more than sodium
thiosulfate entirely odorless. It's that Vinegar odor
which was first to go from my compact DR. That
odor permiated the entire house. Dan
I hope at 1:24 that you fix for a lonnnnng time. What's your time to clear?
Originally Posted by dancqu
What WAS the clearing time? Can't pin it down. I've
Originally Posted by Paul Verizzo
notes some where. Quite sure it must have been less
than 10 minutes. The time would depend upon the
film. I recently put a roll of Pan F+ through a 1:5
dilution of straight sodium thiosulfate anhydrous
fixer. Clear in 10 minutes. Volumn, 500ml, 16
grams of the dry concentrate.
Slow but not too slow. The fix is fresh at start
and dumped at end. For some time I was using 15ml
of rapid at a yet higher dilution but suspected the
liquid had aged so uped the amount to 20ml. Dan
Ten minutes to CLEAR? That's 20 minutes in fixer with the standard margin of safetly. And not T-grain, I'm presuming.
Originally Posted by dancqu
I'd rather have it done in a couple of minutes - even with T-Max - and move on. (Full disclosure: Even one minute will clear T-Max in my fixer, but it needs a few more to help get rid of the stain. Er, dye.) No need to mix with every session and lasts "forever."
"Ten minutes to CLEAR? That's 20 minutes in fixer with the
standard margin of safety."
Standard margines of safety do not work with when
using highly dilute minimal chemistry fixers. Neither
does the FT-1 test. The fixer after use is so little
loaded with silver that a precipitate is an
impractical gage of exhaustion.
"I'd rather have it done in a couple of minutes - even
with T-Max - and move on. (Full disclosure: Even one
minute will clear T-Max in my fixer, but it needs a few
more to help get rid of the stain. Er, dye.)"
That makes two of us, a couple of minutes would be
just fine but sodium thiosulfate in very dilute solution
simply takes more time. I've read though this NG of
10 minute times when using RAPID fixers. Likely
when fixing iodide loaded films.
I used to be enthralled by the speed of Rapid fixers.
My first bottle was 50 years ago. A real God send when
I was knocking out 30 to 50 8x10s in an evening. Now is
different. Maybe a dozen rolls this year and averaging
a minimum of several hours each. So, I'm going to
sweat say 5 minutes more? No chance and not
with the film either. Besides I've other things
to do while the film is fixing. Dan