Claudio Bonavolta wrote:
Following my quest for a non-acid rapid fixer due to my sensitivity to sulphur dioxyde, I would like to thank all of you who replied either through the list or directly.
I was also looking for a fast fixer. Fast fixers are normally based on ammonium thiosulfate but F-9 is described as being fast *and* based on the more readily available sodium thiosulfate. So I compared the F-9 modified formula to Ilford Rapid Fixer at 1+4 (typical film strength) by putting a film leader in each and measuring the time it took to clear. I used of course the same film type from the same lot (from a bulk roll) and the temperature of both fixers was identical. The clearing was just slightly slower, a few seconds, in the F-9, so, from a practical point of view, I just keep the same fixing times. Looks like the ammonium ions coming from the sulfate are making the difference but my limited chemical skills do not allow me to be affirmative on this.
[snip]Back when I was trying to use F-9 on Kodak Elite Fine Art paper using the Ilford short fixing times method, I found that F-9 was just not fast enough, though faster than F-6. IIRC, it took about 2 minutes to really fix the paper with that, and that was way over the 30 second maximum for that method. Since that great paper is no longer available, I have not sought a replacement for Kodak Rapid Fix (that I do not use). I have no trouble with sulfur dioxide, but perhaps that is because I use F-6 fixer instead of F-5.
-- .~. Jean-David Beyer Registered Linux User 85642. /V\ PGP-Key: 9A2FC99A Registered Machine 241939. /( )\ Shrewsbury, New Jersey http://counter.li.org ^^-^^ 07:25:01 up 29 days, 8:45, 3 users, load average: 4.67, 4.69, 4.55 ============================================================================================================= To unsubscribe from this list, go to www.freelists.org and logon to your account (the same e-mail address and password you set-up when you subscribed,) and unsubscribe from there.