I believe this is on point for the thread - Can rapid fixer simply be diluted more and the fixed for longer? I seem to recall using 1+9 rather than the bottle recommendation of 1+4 for ilford rapid fixer?
And further, what sort of fixing times are people using for 1+4 dilution fixing at 20C? I am currently fixing for around 4 minutes with 10s agitation, 10s stand (give or take).
Absolutely, however that removes the advantage or RAPID. So why not use standard fixer.
Dilution tends to be proportional to time double one double the other , that would be a reasonable starting point.
You will not cause any harm by looking, soon after the start of fixing the film is largely insensitive to light. If it has not cleared carry on.
The rule of thumb is that fixing time should be double the clearing time.
I have more than once refixed films that were found to have unclear areas when dried, with perfect negatives as a result.
Fixing is the process of removing the residual unexposed silver halide from the film,, it makes no difference,within reason, if it takes two steps to achieve this.
It only wastes your time, thee result is the same.
Rapid fixer does not do a better job than regular fixer, the difference is time not quality.
Many proprietary fixers have contained a mix of both sodium thiosulfate and ammonium thiosulfate, they all work equally well, they just have different fixing times.
Most have additions of allum to harden the gelatine, and sodium metabisulphide to acidify the solution (this neutralises any developer carry over)