All-powder b&w film processing

Discussion in 'Film and Processing' started by tom_halfhill, Jan 14, 2022.

  1. Well, also RC paper washes a lot faster than fiber based paper,
    to get the chemicals out of the fibers. So to be eco-friendly, use
    more of that.
     
  2. Way back, Ilford published their multiple water change method of washing that used very little water. Can't remember how many changes of water it took, but it wasn't that many.
     
    rodeo_joe|1 likes this.
  3. More specifically, it works using non-hardening rapid fixer.

    Hardening fixer slows down the diffusion rate.

    Kodak rapid fixer has optional hardener.
     
  4. A five-minute wash isn't a brief rinse. I don't run the water full speed, but it's fast enough to wash the film thoroughly. Also, after this tap-water wash, I fill the tank with distilled water and agitate vigorously for one minute before dumping it and pouring in the Photo-Flo for 30 seconds. (I dilute the Photo-Flo with distilled water, too.) This technique prevents virtually all suspended particles left by the processing chemicals and wash water from embedding in the soft emulsion. And I hang the film to dry without wiping.

    The distilled water is important because I found that some city water is "sticky." I don't know how else to describe it ... it just doesn't rinse completely clean. Of course, water varies from place to place, but distilled water is a constant.

    Recently I digitized almost 500 b&w negatives from the 1970s and 1980s that I donated to my university. They were stored in archival plastic sleeves and looked as if they were processed yesterday. They required very little spotting.
     
  5. The Ilford method for fast washing fiber-based paper works by using a nonhardening fixer for the minimum time required to fix the paper. Ilford originally recommended 30 seconds, but further research found that 60 seconds works as well and ensures complete fixing even when the fixer is gradually exhausted during a printing session. After the fix, the paper is immediately rinsed in water, then hypo clear, then a final wash for 10 minutes.

    My version of this technique is to transfer the print from the hypo clear to a large tub of standing water. I let them soak until I'm finished printing for the day. Then I wash them all together in an archival washer while I clean up the darkroom. Usually they get at least 20 minutes. My residual-silver tests confirm they are fully fixed, and my residual-hypo tests confirm they are fully washed. Prints processed in this manner show no fading after 20+ years.
     
  6. I can say the same for my negs, that have never seen distilled water, only filtered tap water. Also no Photo-flo, only a drop of domestic washing-up detergent added to the final wash.

    Plastic sleeves were a rarity back when I bought my storage files; they came with 'glassine' paper sleeves, that continued to be supplied for many years. It's only recently that plastic sleeves have displaced them as standard. I find the static build up on plastic sleeves sometimes makes the strips of negatives a bit difficult to extract. Plus the thickness of the plastic means that less film can be stored in a given volume of folder. So I still prefer the glassine sleeves.. when I can get 'em.
     
  7. Distilled water may not be necessary but is a precaution. Tap water can vary widely, even by season. When I lived in the southern USA, the tap water at certain times of year contained small amounts of algae that altered the taste. Now I live in California, where the tap water is virgin melted snow from the Sierras. Because distilled water is a constant, it eliminates a variable that may or may not matter. I also use distilled water to mix film developers and Photo-Flo.

    Glassine sleeves are considered nonarchival, but a few of my early negatives stored in glassines show no harm after many years. Even so, I switched to plastic (not vinyl) sleeves in the 1980s. Mine hold six strips of five frames, so I bulk-loaded my b&w film with 30 frames per roll.

    My description of Ilford's fast-wash method for prints forgot to mention it requires nonhardening rapid fixer (ammonium thiosulphate, not sodium thiosulphate), and it must be mixed at film strength, not paper strength. In other words, a stronger dilution than normally used for paper.

    Ilford's method is based on research which found that the relatively large fixer molecules become entangled in the paper's microscopic fibers and are very difficult to wash out. Minimizing the fixing time will minimize the entanglements. Using a rapid fixer mixed at film strength fixes the paper in less time (30-60 seconds), so the fixer molecules have less time to embed in the fibers. The first water rinse (60 seconds after fixing, with agitation) removes the gross amount of fixer clinging to the paper surface. Then the hypo clear goes to work on the embedded fixer. Finally, the 10-minute wash removes the rest.

    My practice of soaking the prints in standing water between the hypo clear and the final wash is beneficial, too. It gradually leaches some fixer out of the paper. During a long printing session (6-8 hours), I change the water occasionally, even though the weak fixer solution in the standing water shouldn't migrate back into the paper unless the paper contains less fixer than the water (osmosis). The only problem with soaking in a tub is that the prints tend to float and stick together. I solved that problem by soaking the prints in my archival washer, which separates the prints between plastic dividers.

    However, we have digressed from a thread about film processing into a discussion about print washing. Returning to the original topic, my college photography instructor said film can be safely washed for only five minutes, even without hypo clear. He said film is like resin-coated paper -- it absorbs almost no fixer. Even so, I used hypo clear, just in case. I never bothered to test my film for residual hypo, as I did with my prints. No matter what washing methods we use, a residual-hypo test is a good verification.
     
  8. AJG

    AJG

    I had a few spots on negatives stored in Agfa glassine negative files after only a few years so I switched to PrintFile mylar sleeves and haven't had a problem in over 45 years of using them. There is also the convenience factor of being able to contact print negatives without removing them from the sleeves or trying to keep them in place while you try to put a piece of plate glass on top of the negatives and paper. Last summer I had a request for some images from the late 1970's, and the negatives were in perfect condition. I have always used PermaWash to shorten wash times, but I have usually given a few extra minutes to be sure that the fixer was gone.
     
  9. You can also buy bottled water of various kinds, with different filtering.

    Most chemists now used deionized water, which replaces all the cations
    with H+ and anions with OH-. Probably also with filtering.

    The only one I used distilled water for is Diafine, as the instructions
    actually ask for it. There are only a few ions that bother most photographic
    chemistry, which is the reason that there is photographic grade.
     
  10. tommyfilmist

    tommyfilmist Moderator

    honestly the only option that would work is to have equipment for flash dehydrating liquids, like how they make powdered lemon juice. would require a completely mixed batch of developer solution, toss it in and powder would come out the other end, that would technically be completely mixed, as it would be the solution being powderized and not the raw ingredients
     

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