How long does it take TF-4 to clear film?

[JJB]

I had a bottle of TF-4 delivered from B&H on 08/27/2010. I mixed it into a new 1 gallon brown photo chemical bottle with distilled water, making 1 gallon total.

The working solution was made from the stock, 1+3, again with distilled water. Put into a new 1/2 gallon brown plastic photo chemical bottle. It seems to have worked well with my prints. The used fixer was discarded after each printing session, not returned to the bottle.

Tonight, with the last of my Kodak Rapid Fixer on its way out, I decided to try out the TF-4 on Tri-X. Before I ran my rolls through it I ran a test using some exposed film leader. It took 4 minutes to clear. Fearing my working solution was bad I mixed up some fresh working solution and repeated the test. It took 4 minutes again.

Most of the comments I have found said that it should clear film in 30 seconds or so. Is this right? Or is 4 minutes the right time to clear a leader?

Thanks!

 

[ntenny]

4 minutes sounds way out of whack. I generally see it clear in well under a minute.

That said, Tri-X tends to "clear" to a pink colour, and if you wait around for the pink to disappear I could believe that would take a lot longer. In my understanding the residual pink dye is widely acknowledged to be mostly harmless.

-NT

 

[JJB]

Hi Nathan- I wasn't talking about the pink in this case. The emulsion is what is not clearing. It does clear in my old Rapid Fixer in about 30 - 40 seconds.

 

[Dan Henderson]

You don't say what size bottle of TF4 you started with, but if I am reading your post correctly, you first diluted the TF4 with distilled water, then further diluted into your "working solution." If so, and unless there is a super-concentrated solution of TF4 of which I am unaware, you diluted it too much. As far as I know, with all TF4 or TF5 fixers, you dilute the concentrate in the bottle 1:3 with distilled water and that is your working solution.

If my interpretation is correct, and assuming your "first" dilution was 1:3, then try some of that solution with no further dilution and see if your film clears faster. 30 seconds is my experience.

 

[JJB]

OK, I have reread the directions. I was under the impression that the gallon was the stock made from the 1 liter of TF-4.

The working solution does clear the film in 30 seconds or so. Good thing I didn't send out any prints fixed with it, and that I ran this test!

Thanks for the help on this!

 

[Rich Ullsmith]

Sorry about your gallon of TF-4! I am also searching for a magic wand which will allow me to undilute errant chemistry.

 

[JJB]

It's just the way my brain was thinking. The bottle says it makes a gallon. The bottle is 1 liter. You mix it 1+3, and 4 liters will not fit in a 1 gallon bottle. So therefore, I make the gallon up to be stock and then dilute to make working. We don't need no stink'n directions!

It's my understanding that beer helps in these situations...

 

[Photo Engineer]

There is a paper dilution and a film dilution as well for both fixers.

PE

 

[JJB]

There is a paper dilution and a film dilution as well for both fixers.

PE

What are the diultions for film vs paper with TF-4? I have looked but can't find any info on a different dilution.

Thanks!

 

[Photo Engineer]

This is just from memory, so I suggest that you look on their web site...... All instruction sheets and MSDS sheets are on-line there.

Film: 1 part concentrate to 3 parts water
Paper: 1 part concentrate to 9 parts water (or this might be 7 - not sure)

PE

 

[ntenny]

The text on the bottle (and at their web site) seems to indicate 1+3 for both film and paper.

-NT

 

[Photo Engineer]

You are correct Nathan. My mind was wandering. It is KRLF that has dilutions for film and paper.

See what happens when you get old and don't check your references? But, I did warn y'all that it was from memory.

Sorry.

PE

 

[Ian Grant]

My internet access is intermittent, so I've lost 2 replies

The choice of film is actually crucial, Tmax clears very slowly, Fomapan very quickly in the same fixer. It's not related to the make/type of fixer, but the emulsion itself.

Tmax films clear very slowly due to the iodide content, Ilford Delta films are a bit faster, HP5 etc are faster still, for some reason Fomapan 100 & 200 clear very quickly.

It's not related to the pH of the fixer, although some neutral/alkali fixers may be better than others.

Ian