Archived posting to the Leica Users Group, 2001/01/31

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Subject: [Leica] @#&$*!!* Watermarks
From: "Anderson, Ferrel E" <AndersonF@ria.army.mil>
Date: Wed, 31 Jan 2001 15:57:10 -0600

I think William Gower made some important points, especially about the
difference between softened, deionized and distilled water.  My preference is to
use distilled water as I suspect that deionized water is not perfectly free of
salts since it relies on an absorption/adsorption process that is not 100%
irreversible.  It's no doubt good enough for film washing applications, as some
have testified.  Softened water is no better than tap water.  As insurance, I
check the "distilled" water to make sure that it is distilled water,  The
easiest test is to taste it.  It should have a flat taste.  The  sure way is to
evaporate some on a clean glass surface, and then check for water marks.

My wash procedure is to rinse the film with tap water after the fixer is poured
out, and then treat it with Kodak Hypo eliminator.  I then remove the stainless
steel reels loaded with the film from my Nikkor tank and  wash them in a
cylindrical reel film washer in running tap water for 10 minutes (If you use the
tank with rinses, Kodak recommends at least ten iterations).  During the wash
time, I thoroughly clean the Nikkor tank and cover and cap with hot tap water,
and then with distilled water.  After the ten minute wash, I return the reels to
the tank, replace the cover, pour in distilled water, cap and agitate for ten
seconds.  I  then dump the distilled water down the drain.  This preliminary
distilled water wash removes the tap water from the surfaces of the film and SS
reels.  I then wash the film according to my normal agitation process (1.5
minutes with agitation for 5 seconds on the half minute) with two iterations of
distilled water.  These last two rinses remove the tap water and its dissolved
salts from the emulsion.  If the tap water is not removed, the salts will
deposit on the surface of the emulsion as the water evaporates in the drying
process.

I then tap the reels still loaded with the film on the counter top to remove
most of the droplets of water from the reels and film.  I then hang the film
with weighted film clamps in an unused room over night.  I don't use Photoflo
with 35mm film, and I don't squeegee the film in any way.  With medium format
roll film I use Photoflo in distilled water because the water droplets that
would remain cause depressions/puckers  in the thinner film.  I just use a
couple of drops of Photoflo per 500ml of water, and agitate in the tank for only
ten seconds since I don't want the Photoflo to penetrate the emulsion.

Result?  Perfectly washed, clear, unscratched negatives with no water marks!!
The down side is that friends who have witnessed this process have recommended
that I see a shrink for my obviously anal retentive behavior! 

Ferrel Anderson