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View Full Version : Selenium Toner, how can you tell it's kaput?



Victor Samou Wong
21-Dec-2005, 21:48
I'm just trying to be economical by recyling it. Is this a bad idea?

Selenium produces very subtle tones, so I can't always tell whether it's still working, especially if I'm toning everything. My question is.. does it break down quickly? Should you make the toner new every time?

Cheers
-vic

Robert A. Zeichner
21-Dec-2005, 21:56
I "recharge" my Toner/Wash aid solution every use with an ounce of concentrated Selenium and an ounce of Wash aid. This gets added just before I tone. When time starts to increase substantially to get the color tone I'm after, I repeat this process. The prints then go into fresh Wash aid solution for a few minutes and then the wash. No problems with this routine for years and not only have I saved money on Toner, but I throw less hazardous materials back into the environment.

robc
21-Dec-2005, 22:01
it will keep from session to session.

how long it lasts depends on the strength you are using it at, the size of the prints, the amount of dark verses light areas in the print, how long you leave each print in the toner. i.e. there is no exact answer to your question.

use a wet work print of the image being toned to compare against the toning as it happens. You can then see how far toning has progressed.

make some small mid grey test strips and use them to test if the toner is still active. i.e. compare against a wet untoned test strip. However, if you are comparing against an untoned work print then if its taking a long time for any toning to happen, then you will know its near exhaustion.

Always filter the toner at the end of a session. Coffee filters work fine. that will make it last longer. don't know why but it seems to help.

if you are using it at 1:20 it won't last for very long. at 1:4 it will last for a lot of prints.

Also, mixing hypo with the selenium is NOT a great idea since they exhaust at different rates.

Victor Samou Wong
21-Dec-2005, 22:40
Thank you both. Yeah I was using it at 1:9 or so....

David Becker
24-Dec-2005, 15:08
I work in the South Pacific and am quite isolated from what happens in "the real world" but I have done a couple of "demonstration prints" in which I tore the print in half and then treated half with selenium. then treated both with Potassium feriyanide. The untreated print bleached and the treated one didin't .

Based on this, I imagine that treating a scrap piece of paper with your suspect toner and taking a moment with fericyanide would test the effectiveness of the protection. Again, I am far away from you guys and out of touch with the latest and greatest, but I suggest this idea, not guaranteeing anything.

By the way, I do cultural photography for the museums and cultural centers in the South Pacific, mostly with Hasselblad, but sometimes with large format. This is the first time I have contributed to a forum, so I don't know what the customs are, and this may be against the unspoken rules (please let me know if this is the case), but I will give the address of a web site put up by the museum in San Francisco where we did an exhibition a few years ago, which shows what we do, in case someone is interested . My photos are never for sale, they are always done for my partner museums/ cultural centers, so this is not a commercial plug. But artistic/technical suggestions would be welcome. www.calacademy.org/exhibits/vanuatu

Victor Samou Wong
24-Dec-2005, 19:26
Hello David and welcome! Your replies are certainly most welcome as well. what a fantastic diagnostic, I'll have to give it a try... anything to save money on chemicals!

Cheers!

Philippe Gauthier
24-Dec-2005, 23:53
I've used the same selenium solution for over two years now, replenishing it whenever it looks weak. The good thing about this is hat very little of this toxic metal finds its way into the environment.

How can you tell your solution is weak?

1. If it tones slowly, or barely at all, it is weak;

2. If a sort of grey powder forms, your solution is near exhaustion; decant/filter and replenish.

It's very intuitive, really.

Ron Mc
25-Dec-2005, 16:41
To drift slightly from the original question, how long will the open stock solution keep? I found a bottle today in the darkroom that had been shuffled to the back.

Ron