Safe to use new solution from old stock?

Discussion in 'Black and White' started by john_hughes|2, Dec 14, 2016.

  1. I have an old bottle (years and years) of TF4 concentrate. Rather than toss it, I mixed up half to working strength. The solution remained cloudy for about an hour but eventually did clear. I've done a film strip test and it cleared the strip in under 30 seconds. It should be safe to use, right?
    Thanks, John
     
  2. I had a similar experience and used it 1:3 with good results. I use it for negative duties and not prints but films from that time have remained stable. I believe it had a shelf life stated at 1 year? My sporadic use these past few years have had me extending my supply duties more than normal.
     
  3. TF 4 is plain old hypo (sodium thiosulfate) and keeps till exhausted. I dilute it 1:4 or 1 lb. per gallon of water if using anhydrous crystals, It's slower acting than TF5 (ammonium thiosulfate) and I Fix for about 10 minutes or till the film clears. I pour it back in the storage bottle and reuse it until after it starts becoming milky then dump it. It's safe to use and also used in swimming pool care. It's also quite inexpensive and easy to mix but has smell which some people object to which I personal don't mind at all. I usually wash for at 10 to 20 minutes then soak the film In a wetting agent for 30 seconds and hang to dry. clothes pins work fine top and bottom. Some, like me, will wipe the excess water off. This is how I've done it for at least 60 years. My old negatives are still fine without stains.
    Bill
     
  4. Thank you for responding! I plan to start developing some old rolls today (everything is old around here, including me). When last I developed film, I was using a two bath process for fixing. I will start there and see what results are achieved.
    Thanks again.
    John
     
  5. Processed a 120 roll of FP4+ in Microphen yesterday. Negatives look just fine, so I'm off and running. Going forward, I will do clearing tests from each film to check the TF4 potency.
     

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