Washing Kodafix out of Film

[Michel Hardy-Vallée]

I've been reading a couple of threads on fixer and what to do after it, but I haven't found the information I wanted on Kodafix so I'd like to ask for some comments on my current film fixing procedure, and whether it could cause me troubles in the long term storage: I'm doing only 35mm and 120 rollfilm.

* I pre-soak, develop, and stop (water for Efke, Vinegar+H2O for other films) normally
* I use Kodafix fixer 1+3 mostly because I do Efke and APX100 films, which are said to have a more fragile emulsion. I fix for 3 mins, continuous agitation
* I then make a quick water wash (30secs)
* I use Kodak Hypo-Clearing Agent 1+4 from stock solution and agitate continously for 2 minutes
* I wash the film for 10 mins in running water. The use of HCA reduces the washing time from 20mins to 10mins, according to Kodak documentation. My reel goes in a bucket with a hole at the bottom to let the water flow. I also empty and fill the bucket 3-4 times.

I've used this on Efke R25-50, Agfa APX100, Delta 400/3200, Neopan1600, and Tri-X 400TX.

So my questions:

- Do I really need HCA in my situation? Is it making a real difference with film?
- Should I wash more longer because I use a hardening agent?

 

[Neal]

Dear mhv,

Your process looks good. The only thing I would worry about is the fixing time. For your next roll, check to make sure the film has cleared (no longer milky) at 1-1/2 minutes (because you use 3 minutes as your fixing time). The desired fixing time is double the clearing time so if the film has not cleared, check it occasionally and double the time it takes to clear..

Neal Wydra

 

[Michel Hardy-Vallée]

Dearest Neal,

Thanks for the clearing help! Would dropping a strip of film in the fixer in broad daylight be significant enough to determine when the emulsion clears?

 

[photobackpacker]

Yes. Having said that, there is a greater threat to your negatives borne by underfixing than there is over fixing. I use Kodafix for 10 minutes on TMax with absolutely no detrimental impact on the image. 3 minutes sounds a bit light. I would go with at least the recommended 4.

 

[Neal]

Dear mhv,

Yes. That will work just fine.

Neal Wydra

 

[Michel Hardy-Vallée]

Thank you all for your suggestions, I'll do my tests this week.

 

[Michel Hardy-Vallée]

Well, I had some time tonight, so I took a strip of Tri-X 135 (400TX) and soaked it in Kodafix 1+3. After barely a minute my strip was crystal clear. I tried also with Ilford Rapid Fixer and got clearance after the same time.

Kodafix's instructions ask for

* 2-4 minutes for films and plates, with the exception of:
* Panatomic-X: 1-2 minutes
* Tri-X Pan and Tri-X Pan Professional for 5-10 minutes

Ilford's instructions just recommend 2-5 mins for all films. I'll stick to 4 mins for normal films, with either Kodafix or Ilford. I suppose the new Tri-X emulsion reacts the same way as the other ones, but I'll go to 7 minutes for Delta films.

 

[Neal]

Dear mhv,

Thank you for posting your results. Remember that as you run rolls through that batch of fixer your clearing times will increase.

Neal Wydra

 

[dancqu]

Remember that as you run rolls through that batch
of fixer your clearing times will increase.
Neal Wydra

That's good advice for those using large tank processing.
Multi-gallon tanks remain full for perhaps months.

For those that use small tanks, and that includes
rotary types, where solutions are over and over into
then out of, one-shot fixer is the way to go.

As an example my last roll of Pan F+ used 20ml of A.
Thiosulfate concentrate in a solution volume of 500ml. Some
what less than 20ml may do. Of course the exact amount
of concentrate needed will depend on the film and it's
exposure. My tests were done with full unexposed
rolls of 120 Pan F+; unexposed is worst case.

S. Thiosulfate, which will store for years, may be used.
In fact the 20ml amount is based on tests done with S. Thio.
If on your shelf use 24 grams penta or 16 grams anhydrous.
It is a slower fix. Again, your film and exposure.

With only A. Thio. concentrate and S. Thio. dry on the
shelf I don't worry if the fix has gone bad, how many rolls
have gone through, how close it is to going bad, or
keeping the bottle clean. Dan

 

[Michel Hardy-Vallée]

Actually that's an interesting thought: can you dilute normal fixer to the minimal amount required for a film and use it without problems?

For instance, my bottle of Kodafix says that 3.8L of 1+3 diluted solution will fix approximately 120 rolls of 620 film (hello Kodak, time to change the labels!). Provided that I need 500ml to fill my daylight tank for 1 roll of 120, I could fix approximately 15 rolls of film with that amount of fixer at this dilution.

If I reduce the dilution of my fixer by a factor of 15, i.e. moving from 1+3 to 1+45, then I could use ~10-15ml of fixer in 490ml of water to have a one-shot fixer.

Does that make any sense?

 

[dancqu]

Actually that's an interesting thought: can you dilute
normal fixer to the minimal amount required for a film
and use it without problems?

For instance, my bottle of Kodafix says that 3.8L of 1+3
diluted solution will fix approximately 120 rolls of 620 film
(hello Kodak, time to change the labels!). Provided that
I need 500ml to fill my daylight tank for 1 roll of 120,
I could fix approximately 15 rolls of film with that
amount of fixer at this dilution.

If I reduce the dilution of my fixer by a factor of 15, i.e.
moving from 1+3 to 1+45, then I could use ~10-15ml of
fixer in 490ml of water to have a one-shot fixer.

Does that make any sense?

That does make sense. Exact amounts likely will need
adjustment. First of all Kodak is probably averaging when
arriving at that 120 rolls. If so, how much averaging, fudging,
are they doing? Allowing for worst case, little or not
exposed rolls, may reduce Kodak's 120 to perhaps 80.

Whatever the exact amount, which I came very
close to by 'pinking' two rolls of Pan F+, I think some
little surplus is good to have. No doubt fixation slows
considerably as the fixer nears exhaustion.

You'll know by testing just how much averaging is being
done. There are not any 'magic' strengths. Thick brew
fixers are used with film because of film's great
tolerance for silver held in solution. That, BTW,
is a BIG PLUS for highly dilute fixer, archival
silver levels are not exceeded.

Running very late. I'll add some how-to today. Dan

 

[dancqu]

... some how-to ...

I arrive at working strength by the splits method.
If I were to bring a liter of A. Thio. concentrate into
stock it would go into 4, 1/4 liter bottles. Any shortage
in volume is made up with distilled water.

A 1/4 liter will be split to 4, 1/16. Splitting a 1/16 into
3 one ounce bottles allows enough for three rolls of film.

One or more rolls or one or more sheets at one time may
be one-shot be processed. Stop bath is superfluous
when using one-shot fixer. One-shot developer,
why not one-shot fixer? Dan

 

[Michel Hardy-Vallée]

Dan, do you calculate the strength of the fixer based on a dip test with a strip of film, or are these calculations based on the manufacturer's recommendations?

 

[Tom Hoskinson]

I arrive at working strength by the splits method.
If I were to bring a liter of A. Thio. concentrate into
stock it would go into 4, 1/4 liter bottles. Any shortage
in volume is made up with distilled water.

A 1/4 liter will be split to 4, 1/16. Splitting a 1/16 into
3 one ounce bottles allows enough for three rolls of film.

One or more rolls or one or more sheets at one time may
be one-shot be processed. Stop bath is superfluous
when using one-shot fixer. One-shot developer,
why not one-shot fixer? Dan

I agree, Dan. That's what I've done with the last several rolls of 120 I processed.

I used a fluid ounce of 60% ammonium thiosufate. I believe that an ounce of anhydrous sodium thiosulfate would also work well as a one shot for a roll of film.

 

[dancqu]

Dan, do you calculate the strength of the fixer based
on a dip test with a strip of film, or are these calculations
based on the manufacturer's recommendations?

Calculating won't do it. Real world testing is needed.
I decided unexposed rolls of film are needed for testing
because I've no intention of adjusting the strength of the
fixer for each and every roll of film. But if one were to
process several rolls of same exposed film, then a
more exact strength could be used.

Take Pan F+ for example. I lowered the amount of S. Thio.
penta to 15 grams and had pink, unclear film. At 18 grams,
better results. At 21.5 grams penta, 15 grams anhydrous,
I could see no color and had a very clear film base. With
that amount I was allowing 12 minutes; the first two
constant then each minute a few seconds agitation.

If I use S. Thio. in the future I'll likely up the amount a
bit for a 10 minute fix and a little more margin. All that
is for unexposed Pan F+ 120 film. None of the silver
halides in the emulsion have been reduced so the
entire amount must be fixed out.

IIRC the a iodide test will work but the fixer is so highly
dilute only a haze of a precipitate will be produced. After
all only archival levels of silver are present.

If some small allowance has been made a short strip of film
will clear. Also, the sulfide test can be made, no stain no
silver. By the same token an expose and develop test
can be done. As for myself colorless crystal clear film
and a positive test using iodide is enough for me.

Likely there are big differences twixt the various films
in the amount of chemistry needed. Just guessing I'd think
Tri X might need 50% to 100% more than the Pan F+
and T & D films as much more. Dan

 

[dancqu]

A one gram correction. Second paragraph: At 21.5 grams penta
should read, At 22.5 grams penta . Dan

 

[Michel Hardy-Vallée]

Hi Dan, I'm working so far only with pre-mixed fixer solutions like Kodak's or Ilford, so that's why I wasn't sure how to adapt your methodology. I've made the test of putting a small strip of film in fixer at the recommended dilutions to see how long it takes to clear, but that's the furthest I mananged to go. I'm not really going into doing my own chemicals, so I'd need a procedure that calibrates with commercial products.

Cheers,
Michel

 

[dancqu]

I agree, Dan. That's what I've done with the last
several rolls of 120 I processed.

I used a fluid ounce of 60% ammonium thiosufate.
I believe that an ounce of anhydrous sodium thiosulfate
would also work well as a one shot for a roll of film.

As you've likely read my most recent post dealing
with some of the details of using sodium thiosulfate,
I'll not repeat.

Certainly an ounce will do for some films, very
probably any of the non T or D through ISO 125
and perhaps even the 400s.

I've not had the anhydrous or penta on the shelf
very many years but think the S. Thiosulfates may be
good indefinitely.

I'll make an exception with the S. Thiosulfates.
Although I do not at present, I'll suggest the spoon for
those who would like to have a quickly prepared fresh
fixer for their film, or paper for that matter. Any
scale good for ounce or better weighings can
be used to determine the average gram
weight of a spoon's worth. Dan

 

[dancqu]

Hi Dan, I'm working so far only with pre-mixed fixer
solutions like Kodak's or Ilford, so that's why I wasn't
sure how to adapt your methodology. I've made the test
of putting a small strip of film in fixer at the recommended
dilutions to see how long it takes to clear, but that's the
furthest I mananged to go. I'm not really going into
doing my own chemicals, so I'd need a procedure
that calibrates with commercial products.

What you want are some pointers towards one-shot
usage of off the shelf fixers. Worst case, an unexposed
roll of any one film, will need a certain minimum amount
of chemistry to complex with all the silver halides. For
best mileage work close to that minimum. You'll need
to test for that by fixing two or three rolls of same
type unexposed film.

I don't know which 120 film you use but for starters
try one ounce per roll of your concentrate in whatever
solution volume needed. I've been using 2/3 ounce of
unadulterated, P. Formulary 60% A. Thio. for my 120
Pan F+. Perhaps Tom H. will tell us with which films
his one ounce amounts have worked.

Off the shelf rapid fixers have added preservative and
ph adjustment chemicals. It is safe to assume that
from one make and model to another there is
some varying of capacity.

I'm sure you'll like your fixer one-shot once you've the
hang of it. Don't forget to skip the stop. Dan

 

[Michel Hardy-Vallée]

What you want are some pointers towards one-shot
usage of off the shelf fixers. Worst case, an unexposed
roll of any one film, will need a certain minimum amount
of chemistry to complex with all the silver halides. For
best mileage work close to that minimum. You'll need
to test for that by fixing two or three rolls of same
type unexposed film.

Ok, it's exactly for that that I lack a proper procedure. I would base my minimum amount on a calculation from the manufacturer's recommendation, but experimentally speaking, what can I use to determine if my fixer is already exhausted after a roll?

BTW, why skipping the stop? Does it exhaust fixer as well?

 

[Tom Hoskinson]

Efke 100, Efke 25 and TMAX 400 TMY. As expected, The TMY required a longer clearing (and thus fixing) time than the Efke. I used 1 fluid ounce (30 ml) 60% Ammonium Thiosulfate from Artcraft.

 

[Tom Hoskinson]

It occured to me that I should add some additional information.

I am fixing one roll of 120 film with 1 fluid ounce (approximately 30 ml) of 60% Ammonium Thiosulfate added to about 470 ml of water (or dilute developer).

I have not fine-tuned the amount of fixer/roll like Dan has. I know that 1 fluid ounce is more than I need.

If I am developing 2 120 rolls in the same tank, I add 2 fluid ounces of concentrated fixer (60% Ammonium Thiosulfate) to a sufficient volume of liquid to cover both rolls of film.

Ilfofix or Kodafix concentrates can be used the same way - you will need to test to determine the volume of concentrate required per roll of film and the fixing time for each film type.

 

[dancqu]

[QUOTES=mhv]
"Ok, it's exactly for that that I lack a proper procedure.
I would base my minimum amount on a calculation from the
manufacturer's recommendation, but experimentally speaking,
what can I use to determine if my fixer is already
exhausted after a roll?"

There is really nothing to it EXCEPT if you intend to test
entire unexposed rolls. Then you'll likely care to have some
answers after a roll or two.

I have considered this alternative approach. Rather than
totaly unexposed give instead some minimal exposure. That
would mean loading the camera etc, etc. Also, going through
a developer the film may pick up some chemical fog. That
would interfere with an evaluation of the fixer's effect.
So I'm back to unexposed rolls for testing fixer.

As for your testing I think a clear untinted short film
strip will do. I may even adopt that method. How do you
manage the short strips? Into the dark with scissors
and light tight box?

Like I said I've not tested A. Thio. for the least needed. The
amount of A. Thio. I use, 20ml for a 120 Pan F+, is based on
the amount of S. Thio. needed. I did test for that.

"BTW, why skipping the stop? Does it exhaust fixer as well?"

In one word, FRESH. Fresh very dilute fixer each roll. Also
there is no need to maintain over a long period of time the
acidity of an acid fixer. Most off the shelf varieties are acid.

I'm comfortable thinking of a highly dilute fixer, acid or
alkaline, as being a water stop. Stop or Go, any developer
is very soon very very dilute. Those high speed H2O
molecules go to work right away. Dan