Archived posting to the Leica Users Group, 2001/01/31
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]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