Topping off Selenium Toner Solutiongreenspun.com : LUSENET : B&W Photo - Printing & Finishing : One Thread
In response to a previous question I had, Doremus Scudder wrote: Ed, Here's something to try: Being also concerned about the impact of introducing a potentially dangerous substance into the environment,I decided simply not to and have been using the same solution of Selenium toner now for almost 2 years without disposing. I simply "replenish" by adding a few ounces of toner concentrate from the bottle when the toning becomes too slow. Carry over diminishes the volume slowly as well and every now and then I add water to make it up. So far, it has worked well with absolutely no side effects and I don't have to toss the environmentally suspect toner. I test the finished prints for residual hypo and silver and all pass the tests. I'd love to hear your thoughts on this.
Does anyone else have comments on this. Does the toning process cause chemical changes in the toner that would in any way be detrimental to the finished print? If not, this seems to be a reasonable practice. The only difficulty I see with it is that one does not know the precise concentration of the toner, but if one gets the desired print color, who cares?
-- Ed Buffaloe (firstname.lastname@example.org), March 02, 2000
All posts on this forum on the life of selenium toner state that it is pretty stable. So one need not be afraid to have any degradation products in the replenished toner.
If the desired change in tone has occured, this implies that the silver has been converted into the desired stable compound.
As for the accumulation of reaction products: I believe selenium toner contains hypo, and heavily used fixer is said to contain salts which are hard to wash out of the print (which is one reason why the two bath fixing method is better for archival prints, and allows for short washing cycles). If the residual-hypo test finds these, too, there seems to be no problem, as Doremus wrote that he checked the prints for that. Also, the hypo in the selenium toner hasn't got all the unexposed silver to work on. So maybe the formation of those salts is avoided?
-- Thomas Wollstein (email@example.com), March 02, 2000.
Haven't checked out, but I believe St. Ansel used selenium toner mixed with HCA. This would eliminate hypo residues. But if there is hypo in the toner, it probably isn't possible.
-- Sakari Makela (firstname.lastname@example.org), March 04, 2000.
Since Ed posted my toning technique for comment (something I've been wanting to do for some time, but just haven't got aroung to, so. Thanks Ed!) I may as well add some of my thoughts and assumptions about what happens, and why it may be a viable techique: Firstly, I don't believe it is correct to assuming that mixing selenium toner with Hypo-Clearing Agent would somehow remove Hypo compounds from the solution. HCA is a washing agent, usually an inert salt or salts, which speeds the removal of residual thiosulfate compounds in the wash water. It doesn't "eliminate" or "remove" anything, despite the names of many products on the market. Another problem with using HCA mixed with the toner is that the HCA has a rather limited useful working life (24 hours in a tray according to Kodak), which is significantly shorter than the working life of the toning bath, even if you discard it as Kodak reccomends. I use a separate hypo-clearing bath immediately after the toner. As regards the problem of fixer compounds building up in a constantly reused and replenished solution of Selenium toner, I have noticed that a black precipitate forms in the toning solution which I have to regularly filter out. I'm guessing that the selenium binds to the silver-thiosulfate compounds and precipitates them out of the solution so that they are not a problem. Having fresh fixer in the toning solution in small amounts from carry-over when tranferring prints from the fixer should not be a problem since it would simply be removed in the wash. That, at any rate, explains my positive test results. I, however, am not a chemist and am not sure if the above assumption is correct or not. I'm hoping that one or more of you photochemistry experts out there can add some significant data and information to this dialog. Regards ;^D)
-- Doremus Scudder (ScudderLandreth@compuserve.com), March 05, 2000.
I am an artist. Im not a chemist. Here is what I understand from above. I like to use sellenium toner for archival reasons so my prints, that everyone loves but never earned me a penney, will be around long after i am dead and gone; therefore: 1) I can use sellenium toner over and over again by adding selenium and water to the saved solution 2) I should hypo clear before the selenium bath 3) I should give the prints 2 seperate fixer baths. IS THIS CORRECT? Also, should i hypoclear the print before the sellenium as well as after? And, how to you test the print for residue after you are done, as suggested above. Help me Help me Connie
-- Connie Steidl (photoartc @prodigy.net), March 13, 2000.
I cannot agree that using HCA mixed with Selenium is good, even if Sir Ansell did same. Because as noted above the HCA has a very short life. I say keep your Selenium seperate, mixed at whatever concentrations needed, top up when toning takes too long (even though it seems to work forever). The selenium is a very stable solution and sometimes throws a precipitate. Store only in galss bottles not in plastic as the selenium can scavenge and stick to the plastic loosing the active ingredient. I love selenium, easy and clean but thoroughly wash prints before toning.
-- David Strachan (email@example.com), March 26, 2000.