tf4 fixer rocks like a hurricane!

[Doremus Scudder]

ROL,

Sure, you can get a quick fix, and to "archival" standards with TF-4 or any "film-strength" rapid fixer with one bath. The downside is capacity. Unless you like to waste a lot of fixer, two-bath fixation is still the best bet. Capacity for most ammonium thiosulfate fixes for optimum permanence is only about 10 8x10 per liter according to Ilford. With two-bath, you can double that easily (approx. 40 8x10 for two liters, and then you can replace the dead first bath with the second and do it again, for even more savings).

I think capacities from the Formulary for TF-4 are based on a bit higher acceptable level of residual silver than Ilford's. It would really be nice to know to what standard their "20 rolls per liter" recommendation is based on ... and, despite 2-bath fixing being archival standard, they don't even mention it. The info from them seems a bit sparse...

Maybe PE or others more knowledgeable than I in this area would care to chime in.

Best,

Doremus

www.DoremusScudder.com

[ROL]

ROL,

Sure, you can get a quick fix, and to "archival" standards with TF-4 or any "film-strength" rapid fixer with one bath. The downside is capacity. Unless you like to waste a lot of fixer, two-bath fixation is still the best bet. Capacity for most ammonium thiosulfate fixes for optimum permanence is only about 10 8x10 per liter according to Ilford. With two-bath, you can double that easily (approx. 40 8x10 for two liters, and then you can replace the dead first bath with the second and do it again, for even more savings).

I think capacities from the Formulary for TF-4 are based on a bit higher acceptable level of residual silver than Ilford's. It would really be nice to know to what standard their "20 rolls per liter" recommendation is based on ... and, despite 2-bath fixing being archival standard, they don't even mention it. The info from them seems a bit sparse...

Maybe PE or others more knowledgeable than I in this area would care to chime in.

Best,

Doremus

www.DoremusScudder.com

Knowing your much published views on 2 fixes, that certainly didn't take long. Like shooting fish in a goldfish bowl.

[Peter Gomena]

I once fixed 80 rolls of T-Max 100 in 1 gallon of freshly-mixed TF4. It was exhausted by the time I finished, trust me. The last few rolls were on the edge.

Peter Gomena

[Doremus Scudder]

ROL,

No disrespect intended! And, of course, I was thinking largely of fiber-base paper when I wrote the above post.

The thing I wanted to point out is that there is "fixer capacity" and there is "fixer capacity." TF-4 is no different; the capacity, especially for fiber-base prints, has to do with the amount of residual silver acceptable in a print, which is directly related to the permanence of the print.

For example, Ilford gives a capacity guideline of 40 8x10-inch prints for their Rapid Fix (notice, this is regardless of dilution). However, when one reads further in their data sheet one finds that this number is for a "high level of image permanence ... for commercial use" and that the target maximum silver concentration in the fixer should be 2 g/l.

Reading further, one finds that "for prints that need maximum stability for long term storage [read, optimum permanence or 'archival,' the standard most fine-art photographers wish to process to] a the maximum silver level in the fixer should not rise above 0.5 g/l." This translates to approximately 10 8x10-inch prints per liter (again, regardless of the dilution). (I'm quoting from the Ilford data sheet; emphasis mine.)

The problem as I see it is simply this: Many read Ilford's 40-print capacity and take it to be for optimum permanence. I imagine the same thing is going on with the capacity recommendations for TF-4.

Unfortunately, the TF-4 data sheet makes no mention of the standards for residual silver in the fixing bath that the capacity recommendations are based on. It would be really helpful if we had more information from the Formulary about this. In the absence of any more details, I think we can safely assume that TF-4 capacities will be similar to the Ilford and Kodak counterparts. After all, it is not the fixer components themselves that determine when a fixer bath is "exhausted" for a given standard, but the concentration of silver thiosulfate compounds in solution in the fixing bath. This, really, has much more to do with the material used than the fixer itself.

Applying the Ilford standard to other products (TF-4 in particular) means that for a truly "archival" fix for fiber-base prints and using a single-bath method, we'd better think seriously about discarding the fix after a throughput of only 10 8x10-inch prints per liter.

Of course, we can certainly do this and be assured of having prints that are really well-fixed for optimum permanence. This seems to me, however, like a real waste of fixer when the capacity for two-bath fixing to the same archival standard is more than double that.

Now, if there are space/time constraints that make two-bath fixing impractical, then, by all means use the one-bath method. It just costs you a bit more for chemicals.

Nevertheless, I think it important that people do not read the TF-4 recommendation of "about 30 8x10 prints" per liter, or the Ilford and Kodak recommendations of about 40 8x10 prints per liter for fiber-base paper and assume that those numbers are to be used when processing for optimum permanence or "archivally." They are given for "commercial use" which translates to less permanence.

Washing may be faster with TF-4 due to its alkalinity, but that is another issue from residual silver in the print.

Sorry this got so long, just wanted to clarify and not have you think I was flaming.

Best,

Doremus

[Fred L]

...This can be critical with some papers like the no longer available fiber Kentmere bromides....

I know it's been hard to find but this is news to me, if indeed true. Attributions ?

[Vincent Malaud]

2 years later, where dø we stand? Is TF-4 your new standard? Or 2 bahts fixing?

[mihag]

I've been using Moersch Alkaline fixer for some time (a fine product), 2 bath with FB, HCA, etc... still I'm facing many question marks. What's wrong with acid sodium thiosulphate fixers that have been in use for so many years. Many photographs survived from that time and they have been fixed in a bath of dilute hypo (paper strength) for 10 minutes or more.

[Willie]

How well does this work if you are having to use very hard water?

[Ken Lee]

The alkaline nature of TF-4 means that a hypo-clearing agent is redundant.

We don't need hypo clearing agent because there no Sodium Hypochlorite in the formula. The fact that it's alkaline is an added benefit.

We can use an acid stop bath if we like, but if we're planning to use the fixer for a long time, the acid will degrade it more quickly.

If you want your film to stop developing immediately, a mild solution of Citric Acid will do the trick... and it's odorless too. You can buy a 5 pound bottle of Citric Acid powder from Artcraft or other supplier and it will last a long time. Even 1 teaspoon per gallon will make the water mildly acidic.

[jp]

2 years later, where dø we stand? Is TF-4 your new standard? Or 2 bahts fixing?

Still using it!