bleach and fix vs. blix

Discussion in 'Film and Processing' started by alan_rockwood, Nov 1, 2010.

  1. Here is a question about processing using bleach and fix vs. processing that uses blix. My question is not which is better. The question is whether, in an automatic machine set up to use bleach and fix, could you just use blix for both of those steps and have the process work OK?<P>
    Here is why one might want to know. Hypothetically one might have a machine that is programmed for separate bleach and fix steps, but only one only has the blix chemicals on hand.
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    Thanks.
     
  2. Probably not.
     
  3. Nothing wrong with not using the machine at all. I had a machine but sold it. Tank, waterbath and a reliable thermometer works for me.
     
  4. Is this for a specific process?
    If the blix works for a single roll in a Nikor tank, it will work in a larger machine AT FIRST. A blix is inherently unstable. It will last until all of the sulfite is used up and then it will sulfurize (solid sulfur will precipitate from the solution). This is a mess to clean up. If the bleach tank is designed to regenerate with air bubbling, then the blix will sulfurize sooner. If you turn off the air, the solution will last longer, but you run the risk of inadequate agitation and leuco cyan dye.
    If a blix worked as well as separate solutions, all processes would have switched years ago. A blix works fairly well in a color paper process where the silver load is low. It was always a much bigger challenge with the higher silver levels in film. I once worked on a film process (ES-8) that used a blix. It only worked because it was designed to be used for two weeks and then tossed. It was also the limiting case in the process. We had to slow down the process to get some extra time for the blix to work. I'll bet very few people remember Process ES-8. If it was better known, it would be referred to as Kodak's Edsel.
     
  5. I have a 3 step E-6 kit. I was wondering if it would work in a Phototherm machine programed for 7 step E-6.
     
  6. When you design and build machines to process films and papers, you are mainly compelled to firmly follow the specifications of the sensitized goods maker. In other words if the machine is for the E-6 or C-41 process you follow the process specifications to the letter.
    That being said, a machine like the ones used by mass merchandisers i.e. the one-hour machines you see all around, sell for perhaps $50,000 or more. Therefore, to prevent the machine from being obsolete in a year or so, you design with change in mind. It is no small task because you must plan for changes in the temperature of the process and the time of immersion in the various solutions. Additionally you must plan for changes in replenishment rates. As an example, some chemicals like the bleach are dependent on continuous aeration so you add a bubbler at the bottom of the tank. Carryover, fluids ridding piggyback on the film or paper are sometimes needed, sometimes squeezed. Photo solutions have different corrosive effects so the materials of construction for tanks, rollers, fittings and the like might need to be changed out or the materials chosen must be chosen with the future in mind.
    Over the years, duel paper and film machines have been designed. The film/paper path is altered depending on whichever. Now you a film/paper path that skips specific baths or alternately a different path adds baths.
    When the specifics of the process are internally altered, you need to know how the material will fare in respect to how the different dyes will react. Will the color balance be OK? Will the archival properties be affected? When you alter a process, say from a two step bleach and fix to a blix that combines the two, you need to consider the manufacture has extensively tested his way and likely you don't have the savvy to test an alternate process. Not to speak about liability if things go wrong. Suppose you market a whiz-bang machine that allows an alternate process and the film/paper fades away in a few years? All machine makers look for the marketing advantage. They burn the midnight oil looking for an edge. Sometimes they leap and triumph sometimes the leap is a costly disappointment.
     

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