one other thing - is it ethanol or isopropol alcohol? Also, how much difference does it make in your drying times?
i've been using the same small bottle of photo flo since 1981.
it only takes a few drops, and a bottle will last a lifetime, why go through
the hassle of re-inventing the wheel ?
Thanks to everyone for the responses.
I think I'll just stick to the photo-flo. I didn't know anything about its preservative properties, so I'm glad that was mentioned.
My bottle is getting low. I'm guessing it'll run out in three or four years. :D To be honest, I did think it was getting low, but I didn't stop to think how little of it I use and how long the remaining solution will last...
For about 15 years I wiped down my negatives with a cellulose sponge after the Photo-Flo dip. I quit doing that just because it seemed like a good way to wind up with particles rubbed into the emulsion.
Edwal LFN for me. Photo-Flo always left streaks on my negs. Don't know why. LFN leaves the film pristine.
I've never tried Edwal LFN. I tried their "no-scratch" stuff on a marginally playable DVD once, though. I thought I was being so clever, but it didn't work, so I used their film cleaner to clean it off. Bad idea. It's no longer marginal.
I suspect that Photo Flo does not fully evaporate. However, if you use it as directed it will be sufficient to absorb into the emulsion and vanish when dry.
Photo Flo is mainly the nonionic surfactant called Triton X 100 and either propylene glycol (PF200) or ethylene glycol (PF600). The dilution ratios are different for these versions of Photo Flo, so if you mess up it will leave a residue.
I don't know the dynamics of negative washing. I'm pretty sure certain substances that are in my well water are not well absorbed by the gelatin, because when I get the surface water off I have no indication on the negatives that the water was anything but distilled. If there is any absorption into the emulsion of the calcium-magnesium compounds that make my water hard, I doubt that a surface rinse would remove it any more completely than a surface wipe. These wiped negatives have been kept for over 30 years with no sign of anything but film base, emulsion and silver. The only times I got any streaking were when I did NOT wipe the negatives. There was a time when I used a sponge squeegee, but found a soft clean cloth to be better. Old-fashioned cloth diapers are my current favorite.
"Photo-Flo always left streaks on my negs. "
To avoid streaks, Roger Hicks recommends hanging the film so that water drains to the sprocket holes on one side. It works fine for me. I haven't had to put sprocket holes in my 120 film.