----- Original Message ----- From: "Gerald Koch" <gerald.koch@xxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx> Sent: Tuesday, May 08, 2012 5:46 PM Subject: [pure-silver] Re: Weird Film Issue - Part IIThe problem with Photo-Flo is that it was initially intended for machine processing and contains an anti-foaming agent. This agent contains a mixure of fatty acids to prevent the Triton X surfactant from creating bubbles. Unfortunately if you use too much Photo-Flo you can get greasy spots on the
film. I do not believe LFN contains this anti-foaming agent.If you use a lot of PF or LFN you might consider making your own from the
following formula. Propylene glycol 250 ml Triton X-100 Water to make 1 literBoth chemicals can be easily obtained from www.thechemistrystore.com and are not expensive. There is no antifoaming agent in this formula. The Triton X is also
used in Kodak's lens cleaner/Kodak's description of Photo-Flo 200, the kind sold in photo supply stores, is that it contains an ionic and non-ionic surfactant. There are a couple of more concentrated forms of Photo-Flo which have slightly different MSDS. I think they are the ones intended for machine processing. The combination of half strength Photo-Flo 200 and isopropanol does not seem to leave any residue on the film. BTW, I can see foaming with Photo-Flo so I wonder about the effectiveness of any anti-foam agent in it. The combination mixture does not appear to foam.
-- Richard Knoppow Los Angeles WB6KBLdickburk@xxxxxxxxxxxxx
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