solve my mystery of selenium toner turning purple

greg zinselmeier · Oct 10, 2021

Hello Apuger's,

Recently my Slenium toner bath has been turning purple after maybe 5-10 prints have been processed.

A. is this Normal?
B. if not, what is causing it?

here is my process

Developer is a PQ type, Stop is citric acid 15g/1L, fix is TF3, selenium toner is 50ml + 950ml,

I develope for 2.5 minutes, drain for 15 secs.
1 stop for 30 secs. drain for 15 secs.
I fix for 2.5 min. drain for 15 secs.

Place in a tray of plain water till I am done printing ( multiple images) then i tone 1 at a time for 2-3 minutes.
drain for 15 secs. Hypo clear for 2.5 minutes, wash for an hour vertical tank.

thank you in advanced for any technical criticism and suggestions

cheers everybody

greg zinselmeier · Oct 10, 2021

Oh it is Kodak Selenium toner, and the paper is Foma Retrobrom, Although I highly think not, it has anything to do with the paper, Also I think the color change has something maybe with Selenium percipitating out?? maybe . . . . anyway . . .

When i pour it back into the plastic jug. the purple/black percipitant sticks to the bottom of the plastic jug, and if i pour out carefully the next time ( a day or two later) the Selenium solution is clear. what is this about?

Doremus Scudder · Oct 10, 2021

I'm not sure if the extra iodide in Retrobrom has anything to do with the discoloration of your toner. It's possible, though. Maybe someone who uses contact-printing papers like Azo or Lodima can chime in here with their toning experiences.

The precipitate you get from used toner is normal. I simply filter my toner before and after use with filter paper or just a coffee filter. Use a dedicated jug for your selenium toner working solution and don't worry about the discoloration; just filter. I replenish my toner by adding a bit of concentrate to the working solution when toning times get too long. With filtering, the toner lasts indefinitely this way.

FWIW, I've never had my toner turn pinkish/purplish.

Best,

Doremus

greg zinselmeier · Oct 10, 2021

thanks, for the thoughts, I will use a filter system for the toner

I will say that I have never had this issue until, I changed paper developer, and used citric acid as stop and used Retrobrom.

My PQ developer is

water 750 ml
phenidone 00.44 g
sodium sulfite 28.35g
hydroquinone 06.29g
sodium carbonate 83.00g
Kbr 00.25g
BZT 00.44g

mshchem · Oct 10, 2021

Are you using indicator stop bath? Kodak and Ilford use Bromcresol purple which turns purple in alkaline conditions, like Se toner??

greg zinselmeier · Oct 10, 2021

Unfortunately no, After I take out my paper out of the developer, I usually continue in a water bath for a few 2-3 minutes to let the highlights continue, then I move it into a "stop" tray . I use 15grams of citric acid per liter for stop . i do not like smell of glacial acetic,However I can tolerate the smell of Ammonia, Like TF3 and Selenium toner. so there you go!!!. I am trying to get away from Metol and Glycin in paper devloper and since Amidol is erratic at best of trying to find. I decided to use a devloper and a paper I can readily get. . Im trying to cut down on how many different chemicals i buy. Since i use Pyrocat HD, I decided to start/make/use- Phenidone in my paper developer, and cut out Glacial as stop.

john_s · Oct 10, 2021

Maybe the purple is precipitated elemental selenium. This can occur if the paper, despite rinsing, is still acidic.
A pre-toning bath of something alkaline might be worth a try. Maybe just sodium sulphite (a simple kind of Hypo Clear which is slightly more alkaline than the pH adjusted commercial one) would be enough. Some people use alkaline fixer which helps in this regard.

mshchem · Oct 10, 2021

Se tends to make cold purple hued tones on cold/neutral tone paper. Is this what you are seeing?? The solution itself shouldn't be purple. Se toner is used to check for complete fixing. If you see black ppt. when you immerse the fixed print into the toner, this would indicate incomplete fixing. This doesn't sound like what you are seeing.

A little black stuff is normal in Se toner, it will cling to the walls of a Jobo bottle.

I agree about trying to use PQ developer. I use Bromophen, love the stuff, no tar, clean working, lasts forever.

greg zinselmeier · Oct 10, 2021

Yes, MSHCHEM, I wastoo, thinking incomplete fix at one point. I think it is time to mix fresh fix. I do agree with you John about the Alkaline Fix. TF3 is an Alkaline fixer. i use the formulea in steve Anchell/Bill troops book , . . . Darkroom Cookbook

greg zinselmeier · Oct 10, 2021

Oh, what Am I seeing ? . . . . .you asked. . . sorry I forgot to answer,. . . . After the prints have toned well and evenly in the solution, and after the prints have left the tray of" the Selenium toner solution". The solution will go from a clear like color to a hazy purply grey color. The bottom of the tray will have a deposit of black/grey like sludge that coats evenly the sides and bottom. . .really where ever the solution stands. when I pour the solution back into the plastic bottle. I clean the tray. When I go back to use the selenium solution the next time I print, the solution is now clear, and the bottom of the plastic jug has a full black deposit on the inside bottom. ???
AS the tray

john_s · Oct 10, 2021

Your KRST will last longer if you can minimize the precipitation by using either alkaline fixer or an alkaline bath before toning.

greg zinselmeier · Oct 10, 2021

I thought TF3 was Alkaline ? no ?
FORMULA #135
TF-3
Alkaline Rapid Fixer
(Bill Troop)
As with TF-2, this fi xer will wash out of negative and print materials more rapidly than
will an acid fi xer. It has the added advantage of fi xing fi lms and papers in less than half the
time of the TF-2 alkaline fi xer.
This formula is similar to Photographers’ Formulary TF-4. However, TF-4 is more concentrated
and slightly less alkaline. The greater concentration of Formulary TF-4 increases the
fi xing capacity to fi fty 8 10 prints or fi lms per liter; the slightly lower alkalinity of TF-4
decreases the ammonium odor.
Ammonium thiosulfate, 57–60% solution, 800.0 ml
Sodium sulfi te, 60.0 g
Sodium metaborate, 5.0 g
Water to make 1.0 liter
Dilute 1:4 for either fi lm or paper. Follow development by a 60-second plain water rinse or
a minimum of 5 full changes of water. Fix fi lms for 3 minutes, agitating for a full 30 seconds
during each minute. Fix paper for 1 full minute with continuous agitation.

greg zinselmeier · Oct 10, 2021

whats the thought and consensus on "fix paper for one full minute with continous agitation" that seems too short, I do 2 1/2 minutes, with 10-15 sec drain. ?????

koraks · Oct 11, 2021

greg zinselmeier said:
Place in a tray of plain water till I am done printing ( multiple images) then i tone 1 at a time for 2-3 minutes.

Consider using a more thorough wash between fixing and toning. The way you describe it your prints are basically left to float in a fairly polluted bath with remnants of fix, developer and stop for a long time, soaking up all the 'goodness'. This creates opportunities for problems with the selenium toner later on.

There's no doubt in my mind that your purple/grey haze is elemental selenium precipitating out; eventually it will settle to the bottom and walls of the container, creating a black film. The extent to which this happens determines how well (or not) your selenium toner can be reused. It sounds to me that in your case, with this extent of precipitation, there's very little merit anymore in reusing your selenium toner; it sounds more like you're using a few percent of it and the rest gets destroyed pretty much right away.

TL;DR: wash your prints (much) better before toning, see if that helps.

Don_ih · Oct 11, 2021

You use a citric acid stop bath before fix. If you don't wash the paper before putting it in the stop, the acidity will kill your alkaline fixer. Acidity is harder to get out of paper than alkalinity - one of the reasons to use an alkaline fix.

greg zinselmeier · Oct 11, 2021

Thanks Dan, good point ! after rereading instructions of TF3, I am now using a "water rinse" stop befor the fix. Thanks for contributing!!!

jpohara · Oct 15, 2021

I use a similar process to the OP but I employ two baths of TF3 fixer. The first bath after the citric acid stop bath does get killed over a session by the remaining acid in the paper, but that gets thrown out at the end of the session anyway. The print then goes into the second fixer bath which, in my experience, survives with its alkalinity intact (it gets used for the first bath the next time I print). The prints sit in a large storage tray with running water until I'm ready to start toning. I've never had a staining problem or precipitate in the toning tray (only the storage bottles).

At first, recognizing the issue with the stop bath breaking down the TF3, I tried just using a running water rinse after development instead of citric acid. I found I had to rinse the print (FB paper) for a full minute in a half in running water to get enough of the developer out of it so that I didn't get brown stains on it later. I decided instead to save the time by using the citric acid stop and two-tray fixation, which is really better for print stability anyway.

Doremus Scudder · Oct 18, 2021

I'd recommend watching your fixer capacity carefully. If you want optimum permanence from your prints, and you are fixing one-bath at "film-strength," then 10 8x10s or equivalent per liter is the practical limit with most rapid fixers. With two-bath fixing at "paper strength," you can about double that, i.e., one liter each of bath one and bath two will fix 35-40 prints.

Since you have selenium toner, use a 1+9 solution as a test for residual silver ~~hypo (fixer compounds)~~. Place a drop on the unexposed (or very light) area of a fully fixed and washed print. Wait three minutes and rinse. Any stain other than a very faint cream color indicates less-than-adequate fixing.

FWIW, I transfer prints directly from the second fix to the toner; zero problems.

Still don't know what the purple cast to your toning solution could be...

Best,

Doremus

greg zinselmeier · Oct 18, 2021

o.k. Thanks Doremus Scudder . . .. ( whene I hear "scudder" I always think of the HBO short lived series Carnival, Although I think prpbably your Scudder has nothing to with "their" Scudder, any way. . . . . Since i am shooting 8x10 film and contact printing 8x10 paper . I am using 40 @ 8x10 per 4 liters. so 5 negatives and 5 prints for 1 liter of TF3. I am now using a somewhat vigorous plain water bath rinse after developement for both neg, and paper.I am fixing for 3 minutes for both! I am using a filter system for my Selenium toner bath. this week end I shot 8 images/ developed /fixed and printed 5 developed and fixed. I have gone straight from fix to selenium toner with no problem ( i mixed fresh fixer and fresh toner) with this new batch this week end) . So far it has not turned purple or stained my tray!!!! so. . .. . .. .??????

Philippe-Georges · Oct 19, 2021

Years ago, when AGFA still existed, I had troubles wit KRST too.
Then an AGFA engineer told me to treat the fixed and shortly rinsed (not really washed) prints in a 2% sodium sulfite solution just before the KRST bath, and all the troubles went away.
BTW, I use a neutral-to-alkaline fixer, and a buffered stopbath.

But, be aware for algae, these are a kind of blue-grayish slimy 'clouds' swimming around in the KRST, and in the sodium sulfite bath, and can easily be filtered out with a paper coffee filter.
These algae can stick on/in the (FB-) paper, and I think that these can go on living in the fiber base of the photo paper, which is a frightening thought...
The black sediment sticking at the bottum of the jug is normal, but change that jug regularly as it provokes some deteriorating of the KRST work solution (I use 1+9).

RalphLambrecht · Oct 19, 2021

jpohara said:
I use a similar process to the OP but I employ two baths of TF3 fixer. The first bath after the citric acid stop bath does get killed over a session by the remaining acid in the paper, but that gets thrown out at the end of the session anyway. The print then goes into the second fixer bath which, in my experience, survives with its alkalinity intact (it gets used for the first bath the next time I print). The prints sit in a large storage tray with running water until I'm ready to start toning. I've never had a staining problem or precipitate in the toning tray (only the storage bottles).

At first, recognizing the issue with the stop bath breaking down the TF3, I tried just using a running water rinse after development instead of citric acid. I found I had to rinse the print (FB paper) for a full minute in a half in running water to get enough of the developer out of it so that I didn't get brown stains on it later. I decided instead to save the time by using the citric acid stop and two-tray fixation, which is really better for print stability anyway.

+1 the two-bath fixing method is a proven regiment in archival processing.

bernard_L · Oct 19, 2021

Doremus Scudder said:
Since you have selenium toner, use a 1+9 solution as a test for residual hypo (fixer compounds). Place a drop on the unexposed (or very light) area of a fully fixed and washed print. Wait three minutes and rinse. Any stain other than a very faint cream color indicates less-than-adequate fixing.

Not for the sake of controversy, but for the quality of information. Selenium toner can be used to test the completeness of fixation (i.e. residual silver halides) rather than completeness of washing (residual hypo). see:
https://www.photrio.com/forum/threads/selenium-toner-as-fixer-test.68246/
as you (Doremus Scudder) stated yourself:
https://www.photrio.com/forum/threads/fixer-testing.156191/#post-2025474

greg zinselmeier · Oct 19, 2021

Thanks everyone! To the question of a double fix bath… do I fix in bath one for 3 minutes, then move right into bath 2 for 3 minutes… what’s the procedure????

greg zinselmeier · Oct 19, 2021

Let me get this correct. For TF3, I fix in “ bath one” for 30 sec. then in “ bath two” for 30 sec.. . . Ok got it. How many 8x10 paper do I get out a liter for bath one? How many 8x10 paper for bath two? I’m assuming each has their own container? Do you ever move bath two to bath one And make a fresh “ bath two” ?

Philippe-Georges · Oct 20, 2021

greg zinselmeier said:
Let me get this correct. For TF3, I fix in “ bath one” for 30 sec. then in “ bath two” for 30 sec.. . . Ok got it. How many 8x10 paper do I get out a liter for bath one? How many 8x10 paper for bath two? I’m assuming each has their own container? Do you ever move bath two to bath one And make a fresh “ bath two” ?

I can't really answer for TF3 fixer, but, to my humble insights, 30 sec. seems rather short, even twice.
The capacity for a fixer bath is not that easy to determine. Ilford advices that 3 g/L. of Ag is allowed before the bath must be discarded.
What I do, and this is my personal procedure, is testing with an Ag test strip the first bath (see attached picture), when the first one exceed the 3 g/L, then the second one becomes the first and bath two wil be freshly made. So this is an endless move on.

About the treatment time: here I follow the manufacturers advice.
As I work with Fuji-Hunt Unilec fixer, which is a neutral-to-slightly alkalic product (pH +/- 7), I fix for 2 min. twice (two bath @ 22°C) and at a 1+4 dilution, this is for fiber based paper (FOMA). Preceded by a buffered stop bath.
This fixer holds for a very long time and can be regenerated, even by just topping off, which is an important environmental plus.

BTW, the first fixer bath always suffers the most as it must endeavour the test printing strips too, and these 'strips' are, in most of the cases, cut with a not so sharp device.
Cutting with a not good (appropriate) knife frills the cutting side and 'loosens' crumbs of the silver holding emulsion which crumble into the different baths, yet the most in the first fixer as it takes some time for 'dissolving' and to come off, and so these particles end in the first fix (after a while you will observe that fix 1 holds a kind of a dark sediment)...

solve my mystery of selenium toner turning purple

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