RE: Polytoner trouble: black specks
DEAR DAN, I am NOWHERE as knowledgeable about this topic as Ryuji and Liam but I do have experience with flaky selenium toner. It can, indeed, be the result of precipitation and, in my case, it is from the large amount of Calcium Carbonate (soft coral) dissolved in our water. Even though I use distilled water to mix my solutions my rinses and holding bath (prior to second fix and toning) are tap water and there is often a precipitate. If the selenium soln is fresh I filter it often...if older I just dump it. Sooooooooooooooo, might be your water supply. CHEERS! BOB -----Original Message----- From: Ryuji Suzuki [mailto:rs@silvergrain.org] Sent: Monday, December 18, 2006 10:39 PM To: alt-photo-process-l@usask.ca Subject: Re: Polytoner trouble: black specks Check out an article on poly-toner on my website. It has a formula translated to standard format from a Kodak publication. In my experience, using KRST as the source of selenium in this type of combination toner has been problematic. I make mine from liver of sulfur and selenium powder, not too dissimilar from the formula in that page. Black precipitate can be silver compound or can be selenium compound. Stain from selenium can be very hard to remove from the emulsion, even if you wipe it with sponge. You should filter them out and cut back on selenium from next batch. But selenium gets consumed from the bath so you should replenish selenium more frequently than sulfur, if you use the bath continually. From: Dan Fuller <dhfuller@wisc.edu> Subject: Polytoner trouble: black specks Date: Mon, 18 Dec 2006 13:44:00 -0600 > I am processing b&w 35mm motion picture prints on Eastman Fine Grain > Release Positive film which I would like to tone. This is a > wonderful, inexpensive, fine grain, blue sensitive film that can be > treated much like RC photo paper. In the past, I used Kodak's > Polytoner--now discontinued--with good results. I run the prints > through a countertop processor designed to develop 100 foot lengths > of microfilm (Recordak Prostar). The toning looks good but I am > getting tiny dark specks on the emulsion side of the film throughout > the 100 foot length. These specks can be removed with water and > gentle scrubbing . . . mostly. When observed with a bright light at > just the right angle they look metallic, a coppery red. > > I tone prints that have already been developed, washed and dried. For > toning they pass through these stages at 90 degrees F: water wash, 2 > tanks of homemade polytoner, water wash, 1 tank of Hypo Clear, water > wash, dryer. > > Each tank of homemade polytoner contains: > Part 1: > Kodak Rapid Selenium 10 ml > Balanced Alkali 20 grams > hot water 250 ml > > Part 2: > Liver of Sulfur 20 grams > Borax 1 gram > hot water 250 ml > > I mix these and add enough hot water to bring the solution up to 650ml. > > For my last run, I carefully filtered Part 2 which tends to be > sludgy, but I still got the dark specks. What are they? What am I > doing wrong? > > I suspect they have something to do with the selenium. Is my toner > too alkaline? Not alkaline enough? > > Thanks for your time. > > Dan Fuller > making silent films in Wisconsin >
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