selenium toner plating out in tray?

[eli griggs]

I just transferred some selenium toner, 1:9, from the covered Ziploc tray I used it/stored it in these last 2-3 years, to wine bottles for easer storage and when I wiped the tray bottom with a paper towel, I found that the sludge filled with metallic appearing flakes. Is this selenium crystals, silver or what?

In my previous life, whenever I finished a job or session using this toner, down the drain it went, so there was no time for this to happen. Now I just replenish the toner when it weakens, without filtering.

What are your thoughts, experience or recommendations?

Eli

 

[Mark Fisher]

Not sure what it is, but I get it all the time in my toner. I just filter it periodically through a coffee filter.

 

[Nicholas Lindan]

It happens if the toner gets acidic (well, less basic) - I am going to try adding a pinch of carbonate to the toner next time it happens to see if that will fix things.

 

[skahde]

It happens if the toner gets acidic (well, less basic) - I am going to try adding a pinch of carbonate to the toner next time it happens to see if that will fix things.

It won't reverse the precipitation, I'm afraid. You can add a little alkali before it happens to make the toner keep better, though.

Stefan

 

[Steve Goldstein]

I've always worried that the actual dilution must be lower after filtering out the gunk.

I recently ran into a similar problem. 1+9 toner solution, mixed in distilled water and stored in a PETE bottle, seemed to plate out after a year, whereas the 6-year-old bottle of undiluted stock from which it came looks as-new. The helpful guy at Kodak advised me that they don't recommend storage of working-strength toner for longer than 2 months. Now try to find that little tidbit on any documentation, either online or on the bottle!

 

[john_s]

An alternative to Stefan's suggestion is to use an alkaline fixer, or use an alkaline rinse before selenium toning.

 

[fschifano]

...or just make sure the prints are well washed before toning. Of course, there will always be some precipitate but it is of no consequence and can be filtered out. One can keep a batch of selenium toner going for a long time by filtering out the sludge and replenishing it with a bit of fresh concentrate now and then. I have some going now for at least a year.

 

[JBrunner]

...or just make sure the prints are well washed before toning. Of course, there will always be some precipitate but it is of no consequence and can be filtered out. One can keep a batch of selenium toner going for a long time by filtering out the sludge and replenishing it with a bit of fresh concentrate now and then. I have some going now for at least a year.

This is what I do. The precipitate seems to form at the air liquid barrier, as evidenced by the presence of it in the cap, and seems more frequent with a half filled jug. I now use a smaller jug kept topped up, and have much less of of it. When I do get it, I filter it through a paper coffee filter in a funnel. Its pretty easy to tell when the selenium needs replenishment, as the toning slows way down.