[bobbotron]

I have a 6 month old bottle of Moersch Selenium toner that's precipitated out a bunch of small black dots. They seem to mostly be stuck to the side of the bottle.. just wondering if anyone knows what this is, if it means the toner is no longer good, etc.

I've been using this on RC prints for longevity and d-max increase. I never see a huge change, but there is a slight change, I quite like it.

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[Digitalis]

I read the MSDS sheet for this toner. It could be the solute sodium selenate decomposing and precipitating out of solution and forming elemental selenium around nucleation sites. Elemental Selenium is typically red, though black/grey allotropes do exist and commonly form in oxygenated environments. Cold temperatures and oxidation are likely culprits here. If you so desire, moderate heating with agitation should re-dissolve the precipitate.

The toner should be fine, as long as the precipitation is brought to a halt. If things remain on their current course, the reduction in selenium content in solution may lead to the toner becoming as effective as tap water.

[bobbotron]

I read the MSDS sheet for this toner. It could be the solute sodium selenate decomposing and precipitating out of solution and forming elemental selenium around nucleation sites. Elemental Selenium is typically red, though black/grey allotropes do exist and commonly form in oxygenated environments. Cold temperatures and oxidation are likely culprits here. If you so desire, moderate heating with agitation should re-dissolve the precipitate.

The toner should be fine, as long as the precipitation is brought to a halt. If things remain on their current course, the reduction in selenium content in solution may lead to the toner becoming as effective as tap water.

Thank you good sir, that's helpful. Oxidization - definitely possible, as it's been open for 6 months. Cold temperatures. It's in a heated basement, but only heated by Canadian terms, it's probably 16 degrees Celsius down there these days. Getting blasted cold outside already.


I will try heating it up a bit to see what happens. It'd be a shame to have to get rid of it already.

[bobbotron]

The Moersch web site is not very straight forward to follow. Curious if you know of any tricks to tell if toner is still active?

[Digitalis]

Try leaving an exposed and developed square of photographic paper half submerged in it for several minutes, a dark piece of test strip will do - the effect of selenium toner will be distinctly visible after 5 mins.

[bobbotron]

Yeah... I left a print in 1:10 solution last night for at least 6 minutes. They are RC prints so I've read a big change is unlikely but.. I didn't really see the image change at all in the print. Bummer.

The MSDS only says to store it under 25C, nothing about minimum storage temperature. My best guess would be it's just too old.

[Digitalis]

My best guess would be it's just too old.

..and what little selenium that was in it has precipitated out leaving the toner utterly exhausted.

[bobbotron]

..and what little selenium that was in it has precipitated out leaving the toner utterly exhausted.

Yep. What a waste, wish I had got around to toning some prints in the summer.