[pure-silver] Re: Weird Film Issue - Part II
- From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Thu, 10 May 2012 10:04:48 -0700
----- 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 II
The 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 liter
Both 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
WB6KBL
dickburk@xxxxxxxxxxxxx
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