Selenium toner geting dark

[AndreiF]

Hi all!
As I understand Selenium toner can be reused, I am wondering way it is getting dark grey after just one sesion? Is this a sign it is eshausted or has something to do with the prints? The prints are developed with Moersch lith developer.any ideeas?
Thanks!

 

[Gerald C Koch]

With use or age selenium toner will throw down metallic selenium which is a grey solid. Just filter it off before use to prevent the sediment from sticking to prints. If a lot of solid forms then the activity of the toner will be less.

 

[bernard_L]

will throw down metallic selenium which is a grey solid

Can that be recycled by preparing toner from scratch, using, e.g. the Dassonville/T55 recipe?

 

[Doremus Scudder]

Can that be recycled by preparing toner from scratch, using, e.g. the Dassonville/T55 recipe?

Nope. The precipitate is usually compounded with silver. Not suitable for making toner from. I filter my toner before and after each session and add a bit of stock concentrate to the working solution whenever toning times become too long.

Best,

Doremus

 

[AndreiF]

With use or age selenium toner will throw down metallic selenium which is a grey solid. Just filter it off before use to prevent the sediment from sticking to prints. If a lot of solid forms then the activity of the toner will be less.

Thank you Gerald for the answer. How to filter it? The coffe filter would work?

 

[pentaxuser]

Would it go dark grey after just one session and if so how many prints is this likely to equate with in that session?

pentaxuser

 

[Doremus Scudder]

Coffee filters work, but real lab-grade filter paper is better. As for when the precipitate forms: it seems to have to do with the amount of carried over dissolved silver compounds and the strength of the toner itself. If you transfer prints directly from the fix to the toner like I do, then it will happen sooner and more often than if you wash prints well before toning. If you have a lot of precipitate every session, there's likely some problem in your processing work-flow that allows too many contaminants to get into the toner.

Best,

Doremus

 

[Gerald C Koch]

Can that be recycled by preparing toner from scratch, using, e.g. the Dassonville/T55 recipe?

I would discourage anyone from attempting to make selenium toner. I am a trained chemist and would not do so without a fume hood. Selenium is toxic both in the elemental form and as compounds. The toner is not expensive and with proper care it lasts a long time.

There are several recipes. However being what it is, they all produce comparable results.

 

[AndreiF]

Coffee filters work, but real lab-grade filter paper is better. As for when the precipitate forms: it seems to have to do with the amount of carried over dissolved silver compounds and the strength of the toner itself. If you transfer prints directly from the fix to the toner like I do, then it will happen sooner and more often than if you wash prints well before toning. If you have a lot of precipitate every session, there's likely some problem in your processing work-flow that allows too many contaminants to get into the toner.

Best,

Doremus

Thank you for the answer! It is not happenning all the time, last time I was getting some prints from fixer staight to selenium, but usually I wash the prints first for 1 hour. When got dak I did have bleached the prints, maybe has to see with this?

 

[Doremus Scudder]

I would discourage anyone from attempting to make selenium toner. I am a trained chemist and would not do so without a fume hood. Selenium is toxic both in the elemental form and as compounds. The toner is not expensive and with proper care it lasts a long time.
There are several recipes. However being what it is, they all produce comparable results.

+100!

Thank you for the answer! It is not happenning all the time, last time I was getting some prints from fixer staight to selenium, but usually I wash the prints first for 1 hour. When got dak I did have bleached the prints, maybe has to see with this?

Andrei,

Refix your prints after bleaching (even local bleaching) and before toning. Rinse after bleaching, then return the print to the fix for the required time. Then tone as usual.

Best,

Doremus

 

[AndreiF]

Hmm, so that s way! Thank you, Doremus!

 

[MattKing]

Refix your prints after bleaching (even local bleaching) and before toning. Rinse after bleaching, then return the print to the fix for the required time. Then tone as usual.

One caution: if you do this, make sure you are using a simple reducing bleach, not a re-halogenating bleach!

 

[palewin]

Doremus's (or others): I have always used coffee filters to strain the particulates out of my used selenium toner. I see from a quick search that lab grade filter paper comes in various degrees of filtration, and low or wet-strengthened versions (it would seem obvious that you need wet strength when filtering liquids?). Can you recommend any particular paper, or suggest what criteria you use in selection?

 

[Gerald C Koch]

Doremus's (or others): I have always used coffee filters to strain the particulates out of my used selenium toner. I see from a quick search that lab grade filter paper comes in various degrees of filtration, and low or wet-strengthened versions (it would seem obvious that you need wet strength when filtering liquids?). Can you recommend any particular paper, or suggest what criteria you use in selection?

Coarse grade is all that is needed. In addition student grade is usually cheaper.

The problem with coffee filters is that you cannot fold them correctly to get a decent flow rate. They're just too flimsy. For those who don't remember here is a video on how to fold filter papers.

 

[AndreiF]

One caution: if you do this, make sure you are using a simple reducing bleach, not a re-halogenating bleach!

Thanks for the advice Matt! If I don t have the oiginal bottle anymore -it is a bleach from a sepia kit- how can I know what type of bleach do I have? There is a test I can make?

 

[Doremus Scudder]

One caution: if you do this, make sure you are using a simple reducing bleach, not a re-halogenating bleach!

Matt, I use a potassium ferricyanide and potassium bromide rehalogenating bleach for just about everything and it works just fine. I like it because it is reversible to some extent and seems to be more controllable. Farmer's reducer type bleaches use potassium ferricyanide and sodium thioisulfite (hypo) and are not reversible. Some workers use just a ferricyanide solution and rely on carried-over fixer to provide the catalyst. In any case, the prints needs to be thoroughly rinsed and refixed after bleaching. I'm not really sure why refixing is necessary with Farmer's reducer, but everything I've read (including the Darkroom Cookbook) says to refix after bleaching with Farmer's formulae. Certainly you need to refix with a rehalogenating bleach. See here: https://books.google.at/books?id=Ba...epage&q=farmer's reducer instructions&f=false

Thanks for the advice Matt! If I don t have the oiginal bottle anymore -it is a bleach from a sepia kit- how can I know what type of bleach do I have? There is a test I can make?

Andrei, Bleach from a sepia toner kit is a ferricyanide/bromide rehalogenating bleach. It will work just fine for bleaching prints without toning afterwards if you dilute it properly (i.e., weaker). After bleaching a print, either locally or overall, you need to rinse it well in running water and then refix it.

Best,

Doremus

 

[AndreiF]

Matt, I use a potassium ferricyanide and potassium bromide rehalogenating bleach for just about everything and it works just fine. I like it because it is reversible to some extent and seems to be more controllable. Farmer's reducer type bleaches use potassium ferricyanide and sodium thioisulfite (hypo) and are not reversible. Some workers use just a ferricyanide solution and rely on carried-over fixer to provide the catalyst. In any case, the prints needs to be thoroughly rinsed and refixed after bleaching. I'm not really sure why refixing is necessary with Farmer's reducer, but everything I've read (including the Darkroom Cookbook) says to refix after bleaching with Farmer's formulae. Certainly you need to refix with a rehalogenating bleach. See here: https://books.google.at/books?id=Ba_OCwAAQBAJ&pg=PA129&lpg=PA129&dq=farmer's+reducer+instructions&source=bl&ots=wOaNWehrNc&sig=mlakaio8Y25GHCJYxXRy4bf8MEc&hl=en&sa=X&ved=0ahUKEwi98Pqw49XSAhXMaxQKHbGjA544ChDoAQglMAI#v=onepage&q=farmer's reducer instructions&f=false



Andrei, Bleach from a sepia toner kit is a ferricyanide/bromide rehalogenating bleach. It will work just fine for bleaching prints without toning afterwards if you dilute it properly (i.e., weaker). After bleaching a print, either locally or overall, you need to rinse it well in running water and then refix it.

Best,

Doremus

Thank you very much Doremus for the answer. I am new to bleaching and toning so if I put to many questions, sorry. What s happening if you use a ferricyanide/bromide rehalogenating bleach before using Selenium? If was just selenium I have to refix after too? I have to refix only if the bleach was not follow by the selenium or has to be refix after both of them too?
Hope are not too many questions, thank you !

 

[MattKing]

The problem with fixing after using a rehalogenating bleach is that the fixer + subsequent wash removes the image that the bleach rehalogenated.
While that may be your intention (bleaching to remove a portion of the image = brightening the highlights), the usual reason one uses a rehalogenating bleach is to permit re-developing that portion of the image in an image tone modifying re-developer - like sepia toner.

 

[Doremus Scudder]

Thank you very much Doremus for the answer. I am new to bleaching and toning so if I put to many questions, sorry. What s happening if you use a ferricyanide/bromide rehalogenating bleach before using Selenium? If was just selenium I have to refix after too? I have to refix only if the bleach was not follow by the selenium or has to be refix after both of them too?
Hope are not too many questions, thank you !

The problem with fixing after using a rehalogenating bleach is that the fixer + subsequent wash removes the image that the bleach rehalogenated.
While that may be your intention (bleaching to remove a portion of the image = brightening the highlights), the usual reason one uses a rehalogenating bleach is to permit re-developing that portion of the image in an image tone modifying re-developer - like sepia toner.

Andrei and Matt, I really need to clear up the confusion I may have caused: I'm talking about bleaching a print to improve highlights, lighten certain areas, etc. I'm not referring to the bleaching that one does when sepia toning or split toning sepia/selenium. If you're doing a two-step sepia toning that requires a rehalogenating bleach, then you definitely don't want to refix before toning (you'd destroy the image).

My workflow involves only toning in selenium, which needs to be done after a print is fully fixed. I bleach only to lighten areas of the print or, on occasion, I bleach back an entire print. I use a rehalogenating bleach to do this with, but I'm not toning the bleached image; I want it gone, so I refix. When one is using Farmer's reducer for similar purposes, on should refix as well. After the print is well-fixed, it can be transferred to the selenium toner. Any bleaching converts the silver into other compounds that need to be fixed out if you don't want them there, hence refixing after bleaching for this reason.

If you're sepia toning, then your finished print gets bleached and then redeveloped in the toning solution, without fixing in between, just a rinse to stop the bleach. The toner converts the rehalogenated silver back into silver sulfide, a stable compound, so the print needs no additional fixing thereafter, just a wash and dry.

Sorry for any confusion,

Doremus

 

[AndreiF]

Hi Doremus!
I have been busy, no time to get on apug. Thank you very much for taking your time to explain everithing. It is everithing more clear for me now.