Selenium Workflow and Problems

[NB23]

Tim Rudman's Toning Book.
This thread has a useful discussion: https://www.photrio.com/forum/threa...-does-not-improve-archival-properties.146864/
The unreliability relates to the fact that you need complete toning in order to get the complete protection - which may be inconsistent with the change in appearance you want. As a result, many people stop selenium toning before longevity is maximized. A selenium + sepia mix is much more reliable.

I remember that thread. If anything, it’s a festival of contradictory statements about toning and image stability.

 

[pentaxuser]

1. 
   
2. Is Berg selenium toner supposed to smell that bad?
3. Is Berg selenium toner supposed to oxidize and turn a shit-brown so quickly (within 90 minutes?)

.

I suppose there might well be a link, even if it is only auto-suggestion, between smell and colour given your description of the colour

pentaxuser

 

[Doremus Scudder]

I have a simple question, which is very pertinent:

“If MGIV does not tone at the same rate as other papers, does it FIX at the same rate?”

... No one will answer this, I’m afraid.

Well, I'll answer this, and I'm not afraid

You're trying to compare apples and oranges here.

Note that fixer acts on undeveloped silver halides, i.e., the unexposed and undeveloped silver bromide/iodide/chloride compounds that are the light-sensitive components of the emulsion. Fixer breaks these down into water-soluble compounds that can then be washed away.

Toner acts on the developed silver image. After development, the image is made up of elemental, metallic silver. Fixer will not affect this at all (the image doesn't get fixed away, does it?).

Selenium toner works by binding to the silver molecules and making silver selenide, from what I understand. This process results in 1) a change in image tone and/or 2) an increase in density.

As you can see, fixing undeveloped silver halides has nothing to do with toning elemental silver. Your premise is simply incorrect. It follows then, that fixing rate has absolutely nothing to do with the rate of toning.

One thing I'm not certain of, however, are the variables/conditions that affect toning rate. Since we're talking about the developed silver grains in the emulsion to which the toner binds, there must be significant differences in these that affect the way and the rate that selenium toner binds to them. This could be grain size or shape or some other variable of which I am not aware. Nevertheless, we all seem to agree that some papers tone more readily than others. I have tried to tone some papers in the past that simply would not tone at all (I remember a Cachet cold-tone paper that didn't change after hours in the toner; the same toner made a significant change in Seagull G in just a few minutes). I don't know enough of the details about the chemistry of the toning process to explain this.

Still, when we are discussing toning rates, we're talking about how the toner reacts/interacts with the developed-out silver that comprises the image, not the residual, non-image-forming silver halides that get fixed and washed away.

The silver image in an untoned print is susceptible to degradation because contaminants can attack the silver that makes up the image. Converting the image to compounds of silver and selenium (again, silver selenide, I believe) by selenium toning protects the image because the resulting compounds are more stable than silver alone. I stands to reason, that the amount of protection provided by such toning is dependent on the degree of toning, i.e., on the extent to which the image silver is converted to silver-selenium compounds. Very little silver converted to silver selenide means that much of it is left unprotected. Most of us tone just enough to make a very small change in image tone or to increase Dmax just a bit. This is usually no where near "to completion," which means that the bulk of the image is still unprotected.

I don't know if you've ever toned a print to completion in selenium, but I have. Warm-tone Bergger CB would tone to an almost tomato-red if toned long enough. Other papers turned milk-chocolate brown and, as mentioned, some papers wouldn't tone at all.

I have to conclude that those papers that did not exhibit a change in either tone or density simply were not reacting with the toner, meaning that toning simply was not occurring. That means simply: no color change or density change = no toning = no protection.

Best,

Doremus

 

[Doremus Scudder]

Doremus,
Yes Selenium binds, sticks on, covers, attaches to, envelops, kisses the silver.

Yes it leaves a sticky and oily residue on my fingers when I handle my selenium toned prints, including mgiv that is selenium treated but without a color change. That binding, is the protective factor, just like sistan.

There is no proof that only a color change guarantees longevity. I will make my own torture test with mgiv prints that will be selenium toned on 50% of the surface. Shall take a year to come back with conclusive results.

Wow, we're getting kind of sensual here with the toning process. "Kissing the silver" is a nice image, but we should be a bit more specific about what really happens when selenium toning.

As mentioned earlier, the sodium selenite, which is the active ingredient in the toner, reacts with image silver in the print to make silver selenide. That's what gives the changes in image tone and density.

That process, in itself, would not seem to leave "a sticky and oily residue" behind on the surface of the print. None of my toned prints, over the course of 40 years of printing and toning, have ever exhibited such a residue. I have to conclude that the residue or sticky coating you feel on your prints comes from something else than the actual toning of the image silver in the print. Maybe some reaction with the gelatin in the emulsion or some contaminant in your toner that isn't washing away properly... not sure here.

I am pretty sure, however, that toning a print in selenium toner should not leave a sticky, oily residue behind. Something seems wrong here.

Note also that Sistan/Adostab works in a different way than selenium toner. There is no chemical reaction going on at all, rather the active ingredient, ammonium thiocyanate, coats the silver in the image (some kind of ionic bond, I believe, i.e., electrical attraction, not chemical binding), thus protecting it from airborne contaminants.

But, back to the reason I posted here in the first place: I find it unfortunate that the myth that a few seconds in weak selenium toner will protect a print fully is still being promulgated. I'm not sure where this came from, but it has been debunked before. Yet, the myth persists. The idea that treating your prints in selenium toner for a shorter time that it takes to make any noticeable change in the image somehow makes them impervious to damage is simply incorrect. Proper fixing and washing is the real path to optimum permanence for your prints. If you want more protection, sulfide (sepia) toning makes a print almost bullet-proof. Stabilizers help too. And, a bit of selenium toning will protect your print a bit. We shouldn't expect more than that unless we can really tone the print completely.

Best,

Doremus

 

[NB23]

Doremus,

I am not the typical printer, and when I say I handle prints, I do not mean one or 5.
For the past three years I went through 50 prints per day, 28 days a month. Yes, colossal. And for the 20 years prior to those three above, I spent 4 days a week in the darkroom, every week.

When I say I handle prints that leave a residue and a weird feeling on my fingers, that’s because I handled at least 300 prints, signing each of them, takes about one hour. A week’s worth. Same as if you’d finger through a 300 page book .

I have no residue when I do this with prints that have been toned in viradon. Or untoned family snaps.

All my time spent in the darkroom made me solve a ton of little unanswered questions to the average, and even expert printer, things that sound stupid at first. The selenium residue on my fingers is one of them.

 

[Doremus Scudder]

Doremus,

I am not the typical printer, and when I say I handle prints, I do not mean one or 5.
For the past three years I went through 50 prints per day, 28 days a month. Yes, colossal. And for the 20 years prior to those three above, I spent 4 days a week in the darkroom, every week.

When I say I handle prints that leave a residue and a weird feeling on my fingers, that’s because I handled at least 300 prints, signing each of them, takes about one hour. A week’s worth. Same as if you’d finger through a 300 page book .

I have no residue when I do this with prints that have been toned in viradon. Or untoned family snaps.

All my time spent in the darkroom made me solve a ton of little unanswered questions to the average, and even expert printer, things that sound stupid at first. The selenium residue on my fingers is one of them.

NB23,

I don't doubt that you are feeling some sticky, oily residue on your prints. My only observation is that, in all my 40 years of printing and toning in selenium, I have never experienced this. I use glossy fiber-base paper, not RC. To me, it seems not normal, but maybe that is simply the case with RC paper. Maybe some other RC paper users will chime in?

Doremus

 

[MattKing]

It is not normal with RC paper that has gone through a post-toning hardening bath. That is what I do with both selenium and sepia toning.

 

[john_s]

.................................

1. Is Berg selenium toner supposed to smell that bad?
2. Is Berg selenium toner supposed to oxidize and turn a shit-brown so quickly (within 90 minutes?)

Back to OP's initial questions, a number of people have reported going straight to KRST from mildly acidic fixer like Hypam (pH around 5), without washing. In the case of the OP, maybe Berg's Selenium Toner does not stand up to the acid as well as Kodak's.

The MSDS for KRST is more informative than that for Berg's, so I can't offer an explanation for it turning brown quickly, other than it being fragile in the presence of acid.

I would suggest raising the pH of the fixer. It could be done with sodium hydroxide if ammonia solution was deemed not worth buying for an experiment.

 

[waffles]

First the print must be fully washed after fixing or staining may occur. If toning exclusively for permanence only brief toning is required (1-2 minutes. Afterwords the print is fully washed again.

This doesn't make sense to me. Because on the bottle of Berg Selenium the first ingredient is Ammonium Thiosulfate. The toner itself contains rapid fixer!! So what is it am I trying to wash away? I've also read that you should use HCA between the fixer and the toner. I've also read that you can dilute the toner itself with HCA. But why would you ever need to use HCA when working with RC paper? It isn't porous!

In short, I am trying to streamline my printing and toning workflow as much as possible. This is important because I am renting the darkroom and only have so much time to print. Also, an more importantly, in the technical documents for RC paper, Ilford specifically says not to let your RC paper be wet for more than 10 minutes or damage can occur at the corners. So there is an upper-limit on how long the paper can be toned. If I am adding unnecessary steps then that only further restricts how long I can tone for.

 

[MattKing]

Ralph's observation is correct if you are toning already washed and dried prints.
As far as diluting toner with HCA, that too is an archaic suggestion, but it used to be a normal practice with fibre papers, even though it was wasteful of toner. The small saving of time it offers doesn't make it worthwhile.
And while you could use HCA with RC papers, it offers no benefit because RC papers wash so quickly.
If you are doing a lot of toning of RC, you may wish to consider slightly larger print borders, so you can trim any edge damage.

 

[john_s]

Putting HCA in selenium toner has been mentioned but is pointless, partly, as you say, because the toner is full of thiosulfate, and also, the toner will last a long time if used carefully whereas the HCA won't last past a day.

The toner will deteriorate if a certain amount of acid gets into it. People who use acidic fixer probably say with good reason that a wash between fixer and toner is essential.

The selenium compound in KRST is actually very like thiosulfate with one atom of sulfur replaced by a selenium atom. No wonder they're compatible.

 

[Doremus Scudder]

Just to add to the collective knowledge a bit.

A wash-aid step before toning isn't necessary. It should come just before the wash. Not to say that it would hurt; it may even help with pH adjustment a bit if you're using a very acidic fix.

Ansel Adams recommended transferring prints directly from the second fix to the toner (we're talking fiber-base prints and two-bath fixing here). However, he used a "plain hypo" second fixer just to avoid the staining that can happen when you transfer prints from a too acidic fix directly to selenium toner.

Using even Hypam or Ilford Rapid Fixer at the 1+4 dilution may also be too acidic; not sure since I haven't tried it.

What I do know is that with Hypam or Ilford Rapid Fixer 1+9 or one of the alkaline or neutral fixers in the TF family, there's no problem with staining when transferring prints directly from the second fix to the toner.

With RC paper and with a one-bath fixing regime there are a couple of possible problems with transferring prints directly from fixer to toner. First, and most important would be to really make sure that the fixer capacity is not exceeded. For a one-bath regime, this is a lot lower than many believe. I imagine that one could get away with 40+ 8x10s or equivalent per liter of fix, maybe even more, but it would be worth keeping an eye on when prints begin to stain in the toner to help determine the fixer capacity. Testing this might be a good idea.

Also, if the fixer is getting on toward the end of its life, it's going to have a lot of dissolved silver compounds in it that might compromise the toner. With a two-bath regime, the second bath has very little dissolved silver in it in the form of silver thiosulfates; most of that stuff stays in bath one. What I'm saying is that when transferring prints directly from second fixer to toner, they are relatively contaminant-free. That is likely not the case with a one-bath regime.

If staining happens or if the toner seems like it getting contaminated, then the thing to do would be to wash thoroughly before toning. This isn't a big deal with RC prints; just a few minutes. With fiber-base prints it's a lot more time-intensive so finding a workable two-bath regime with a fixer that's not too acidic so one can go directly from second fix to toner might be worthwhile.

Best,

Doremus

 

[john_s]

Using a second bath of inexpensive sodium thiosulphate might be worth doing even if one didn't want to go to the trouble of using a two bath fixing routine. It would mean not promoting the second bath to replace the (discarded) first bath but would help avoid the risk of staining. It does mean one more tray if you have the space.
A dash of sodium sulphite could be added to the second bath as a preservative.

 

[Doremus Scudder]

Lloyd Ehrlich has a good discussion about "plain hypo" fixer here: https://www.heylloyd.com/technicl/plain.htm

Note that both sodium thiosulfate and sodium sulfite are used. john_s' suggestion is a good one if one wants to avoid staining. The plain hypo would function as a pre-toning pH stabilizing bath and get rid of a lot of the dissolved silver thiosulfates as well.

But then again, it's just good old two-bath fixation. One could use Hypam or Ilford Rapid Fixer 1+9 or one of the TF family of alkaline fixers just as well. These could then be promoted to bath one, giving a bit more economy to the whole process.

Best,

Doremus

 

[john_s]

Lloyd Ehrlich has a good discussion about "plain hypo" fixer here: https://www.heylloyd.com/technicl/plain.htm

Note that both sodium thiosulfate and sodium sulfite are used. john_s' suggestion is a good one if one wants to avoid staining. The plain hypo would function as a pre-toning pH stabilizing bath and get rid of a lot of the dissolved silver thiosulfates as well.

But then again, it's just good old two-bath fixation. One could use Hypam or Ilford Rapid Fixer 1+9 or one of the TF family of alkaline fixers just as well. These could then be promoted to bath one, giving a bit more economy to the whole process.

Best,

Doremus

My suggestion was based on being careful, being fairly simple, and avoiding perhaps using as a second fixer something that might verge on being too acidic. That's why, when I get a new 5L of Hypam, I add some ammonia solution to make the whole lot close to neutral.

 

[john_s]

Maybe Hypam is a bit too acidic. Acid is known to cause elemental selenium to precipitate out of the toner.

I add a little ammonia solution (sometimes called ammonium hydroxide) to Hypam to make it neutral. I use the quite strong product labelled 25%. I don't have my notes with me so I can't tell you how much, but it's quite a small amount, something like 50mL to the 5L container of concentrate. In a week I will check the actual amount and correct this post.

I have now checked my notes about the quantity of strong ammonia solution to add to Hypam to bring the pH to near neutral. I add 60mL to 1L of undiluted Hypam.

If you want an alkaline fixer you would add more.

 

[MattKing]

Needless to say, but you probably don't want to add ammonia to Hypam if you also intend to add hardener!