Selenium toning question

[Bill Burk]

These words "only on the edges" keep coming back to me....

Perhaps there is something going on with the way you stack and shuffle prints in the fixer that gives the edges more exposure to unwanted fixer compounds. NB23, did you say you process several sheets in developer, lifting and cycling through sheets for the entire development time and then transfer them to fixer where you do the same thing? Or do you develop them one sheet at a time and transfer to fixer while you develop the next sheet?


I get better results when I pay as much attention to the print in the fixer tray as I do when the print is in the developer tray. (That's something I think I picked up from a Fred Picker's Zone VI newsletter).

 

[Doremus Scudder]

Two questions arose:

1. 50 years (and more) ago, everything was fixed in a non-rapid sodium thiosulphate fixer, books say for at leat 10 minutes, but many said the longer the better, single bath only, yet many, many prints are just fine today.

2. can't a fixer be formulated in such a way that the so-called insoluble complexes wouldn't form at all?

1. Two-bath fixing with conventional sodium thiosufate fixers was best practice 50 years ago as it is today. Kodak references from 1929 mention it, Ansel Adams recommended it, etc., etc. And yes, many of those prints are still just fine today.

2. Sorry, but that is beyond the laws of physics as we know them. Short story: the sodium/ammonium thiosulfate goes through several reactions with the unreduced silver halides in a photographic emulsion before insoluble compounds are created. When the amount of by-products and silver in the fixer build up, they inhibit the final stages of these reactions, leaving insoluble compounds. Fixer exhaustion is more due to a build-up of impurities/by-products than running out of active ingredient.

That's why two-bath fixing is really good. Fixing bath one does most of the heavy lifting, but, when impurities build-up, cannot fix adequately. However, we can still use it and take advantage of its partial fixing ability and then use a fresh second bath to finish off the final stages. Since this last step in fix two produces very few by-products, the second bath stays fresh for a very long time and can be substituted for the first bath after the first bath has reached capacity. This both ensures adequate fixing and most economical use of the fixer.

Hope this helps,

Doremus

 

[miha]

1. Two-bath fixing with conventional sodium thiosufate fixers was best practice 50 years ago as it is today. Kodak references from 1929 mention it, Ansel Adams recommended it, etc., etc. And yes, many of those prints are still just fine today.

I'm not saying that two-bath fixing isn't the best practice, just that I haven't found any refernece to it apart from Ansel Adams. That 1929 Kodak reference sounds interesting.

2. Sorry, but that is beyond the laws of physics as we know them.

Not necessary. Ag(S2O3)- monoargentomonothisulfate does become soluble if there is plenty of excess thiosulphate available. A fixer could perhaps be formulated in a such way as to allow thiosulphate relase when needed. Wishful thinking I guess.

 

[Bob Carnie]

What paper?

Ive had this staining even with fully washed prints.

 

[NB23]

What paper?

Hi Bob,

Ilford FB MGIV RC and FB. But I also had it happen with Oriental.

Bill might be on the right track with the Borders being more prone to exhausted fixer... But then again, the first prints will get a stain, the latter ones won't and so on. Maybe I should rock the tray harder.

 

[Rafal Lukawiecki]

These words "only on the edges" keep coming back to me....

Bill, I'd wonder if stains would be more visible in white border areas than the denser regions, elsewhere.

 

[Rafal Lukawiecki]

Grant Haist advocated that only obout five 8x10 sheets can be fixed to archival standards in one gallon of fixer. The number can be extended to 40 when two bath are used.

Miha, since you seem to be interested in fixation, I wonder if you have seen the statement made by Ilford, in this document (page 3, right-hand column, point 3): "Use a single fixing bath plus a washing aid. The number of prints through the single fixing bath can be increased to approximately 40 8x10" prints per litre working solution." in contrast to the capacity without a wash aid: "Fix only a few prints before replacing the fixing bath (approximately 10 8x10 inches prints)." while discussing optimum/archival aims, using modern, less-acidic, ammonium thiosulphate, rapid fixers. Those are somewhat different from the ones Haist generally writes about in his excellent "Modern Photographic Processing" vol 1, where he mainly refers to sodium thiosulfate fixers, with only a footnote (on page 644) to ammonium thiosulfate fixer, and only "if sufficiently diluted—for example, 1:3 for films but 1:7 for prints". Ilford Rapid Fixer, in the optimum/archival sequence, is used significantly more concentrated, and for a shorter time, not to mention that that fixer is less acidic, and it also seems more buffered. I am in no way negating Haist, whose book I specifically got to understand his observations about fixation, I am just wondering if things have, perhaps, moved on since those days, especially in view of the current manufacturer claims, made in relation to their, modern, papers.

I didn't want to derail this thread into a discussion of print fixing, apologies to Mr Rusty, and as we had a lively discussion of this aspect on (there was a url link here which no longer exists), perhaps it could be of interest to you, too. Please accept my apologies if my remarks feel intrusive in any way, I am genuinely interested in opinions on this subject.

 

[miha]

Hi Rafal, I have seen the document and I do remember your interesting thread regarding fixation. I'm no expert, so I can't offer you a valid opinion on the matter, however Gudzinowicz was quite clear on the matter by saying that HCA can't remove the potentially detoriating monoargentothiosulfate only a fresh bath of fixer can do that.

 

[Doremus Scudder]

Hi Bob,

Ilford FB MGIV RC and FB. But I also had it happen with Oriental.

Bill might be on the right track with the Borders being more prone to exhausted fixer... But then again, the first prints will get a stain, the latter ones won't and so on. Maybe I should rock the tray harder.

Tray rocking is a fairly lousy agitation method, especially at very short times, unless you really work hard to make sure there is fluid flow across the entire face of the print. Sending a wave back and forth across the solution surface does not necessarily move the solution around very much.

Try manual agitation by brushing the print surface lightly with your fingertips, tongs, paintbrush, etc. That's one reason I like longer fixing times; I can be reasonably sure the entire print gets adequate agitation. FWIW, I use rubber-tipped tongs or my (gloved usually) fingertips to press an area of the print down into the solution. This usually raises another area, which I subsequently submerge. I continue this, coupled with some swishing till the time is up.

Inadequate tray rocking would definitely cause insufficient fixing at the print edges, especially if the tray is not much bigger than the print size, since this tends to inhibit fluid movement at the edges.

Best,

Doremus

 

[clayne]

These words "only on the edges" keep coming back to me....

But think about which part of the paper has the most undeveloped silver: the white/undeveloped portions. Anyways, all of this nonsense stops once 2-bath fixing is put into use.

 

[Bill Burk]

Followed some of the threads and they sure get deep.

Not sure that I can say yet what the outcome will be for me, I may change to 2 bath fresh, or stick with 1 bath full attention to print the entire time it's wet. The latter has always seemed to work for me, while slacking attention to one detail or another seems to lead to stains.

 

[clayne]

If you do the batch method, it's not anymore difficult - just an additional step right before washing. I usually throw the entire stack of "held" prints in the 2nd bath fixer (which I pour at the end). Agitate each print for 1-2 minutes and then place into the print washer if direct, or set aside in another water filled tray before selenium toning.

 

[Bill Burk]

I started a new thread because I ran into staining last night and I know what I did wrong...

I think my problem is going from acidic Fix to Toner without washing completely.

(there was a url link here which no longer exists)