So I did my first clip test and.....

[RattyMouse]

...am wondering how to use the measurement gathered.

First off, I made a fresh batch of Ilford Rapid Fixer.

Thank I put a drop of this on a piece of Fuji Acros 100 film. By my measurement the film was clear around 45 seconds later. Does this sound right? I find the end point of this test someone ambiguous as the drop of fixer obscures the film pretty well. I wiped it clean at 45 seconds and it seemed clear. At 30 seconds it seemed hazy.

OK, now with this number, I read that the fixer is spent once a clip test exceeds twice this value, which is 90 seconds.

I just have to keep using Acros 100 film as my benchmark film right? I process HP5 and Delta3200 films a lot, but should only use Acros 100 for the clip test.

Is there a rule of thumb about how many 120 rolls of film I can process with 2 liters of rapid fixer? I would like to keep this very simple and just toss the fixer once a certain number of rolls have been processed.

I do not process any TMAX films, which I read depletes fixer faster. I also don't process any Delta 100 or 400 films.

Thanks!!

 

[MattKing]

There are specific capacity recommendations in the Ilford data sheet for their fixers. The data sheet is on their website, accessible from one of the drop down menus admacent to the listing for the fixer.
Kodak has similar information on the film processing matrix that applies to their products.

 

[Tom1956]

The rule "fix for twice the time it takes to clear" is a good rule of thumb for used fixer. It doesn't mean a minute just because fresh fixer clears in 30 seconds. Rapid fixer is for 2-4 minutes by the Kodak instructions, and 10 minutes for regular Kodak Fixer and similar formulas. I never counted the number of rolls to determine worn out chemical, or ever used a chemical test. You can tell when fixer is old without all that. Simply stated, it starts getting nasty looking. Has trash floating in it, or gets cloudy-ish, or smells stinky. Of course the 2 bath is still the best policy. The problem with fixer is that problems take 1/2 a lifetime to show up; then it's too late.

 

[Truzi]

I'm no wizard at this, but I do a clip test before every developing run to see how the fixer is doing - and I usually do the test with a piece of film leader of what I'm actually developing and fixing at the time. Different films will take different times.

Some people will standardize with a piece of t-grain film for all fix tests because it generally takes longer to clear. Basing the fixing time on the t-grain film gives a safety margin, as it is longer than a conventional grain would need (erring on the side of caution).

Following the data sheet for the fixer will not steer you wrong. Some will argue that you will waste fixer that way, but at least you won't be under-fixing your film, which is more important. Also, as stated in many posts, record the time to clear on your freshly mixed fixer. When reusing it, if the clip test takes a certain amount of time longer (I think most people say twice the time), then it is time for new fixer.

I'm bad at keeping track of the fresh and re-used clearing times, and bad at stretching things. So now I also keep track of rolls processed. Using a marker or grease pencil I put an hash mark on the bottle for each roll done (and I still do the clip test).

Also, I'm starting to use rapid fixer, but keep a packet or two of Kodak's powdered fixer as a backup.

 

[Doremus Scudder]

...am wondering how to use the measurement gathered.

First off, I made a fresh batch of Ilford Rapid Fixer.

Thank I put a drop of this on a piece of Fuji Acros 100 film. By my measurement the film was clear around 45 seconds later. Does this sound right? I find the end point of this test someone ambiguous as the drop of fixer obscures the film pretty well. I wiped it clean at 45 seconds and it seemed clear. At 30 seconds it seemed hazy.

OK, now with this number, I read that the fixer is spent once a clip test exceeds twice this value, which is 90 seconds.

I just have to keep using Acros 100 film as my benchmark film right? I process HP5 and Delta3200 films a lot, but should only use Acros 100 for the clip test.

Is there a rule of thumb about how many 120 rolls of film I can process with 2 liters of rapid fixer? I would like to keep this very simple and just toss the fixer once a certain number of rolls have been processed.

I do not process any TMAX films, which I read depletes fixer faster. I also don't process any Delta 100 or 400 films.

Thanks!!

Learn how to do a clip test right! There are probably hundreds of posts here describing the process, and you have it wrong. So, to recap:

First put a drop of fixer on a scrap of film. Wait 30 seconds THEN immerse the entire scrap in a tray/dish/tank of fixer. Start timing and agitate. Make sure the lighting is good so you can observe the results. When the rest of the film is so clear that you can no longer tell the difference between where you put the drop and the surrounding area, that is "clear." And, the time it took to reach "clear" from when you immersed the entire scrap and began timing is the "clearing time."

If you do the above, you won't have any problem seeing when the film clears and finding the right clearing time.

Do a clearing test in fresh fix for every film you use to find a "benchmark" time for determining fixer exhaustion. You can't use one film to determine the clearing time for another film. The "benchmark time" is ONLY for deciding when to toss your fixer. Discard fixer when the clearing time for a given film is twice that in fresh fixer.

To use clearing time to determine the correct MINIMUM fixing time for film, you must do a clip test immediately before processing in the fixer you are planning to use with the film you are planning on fixing. Note that the clearing time in used fixer will be longer than that in fresh fix. Then, use this time as a guide for determining MINIMUM fixing time.

Now we can talk about fixing times: First, although Ilford and others specify at least twice the clearing time as a guide for proper fixing time, many others recommend THREE times the clearing time for a proper fix. Yet others advocate using at least the manufacturer's minimum fixing time and no shorter, regardless of the clearing time.

So, what do I do in light of all this? First, since film is coated on a waterproof base and moderately longer fixing times will do no harm, I fix longer than the MINIMUM time. I also use two-bath fixing whenever possible. My rule-of-thumb is: THREE times the clearing time plus 10% (for fixer exhaustion during processing) or the minimum manufacturer's recommended time, whichever is LONGER. This time is divided equally between two baths for me, but you can use single-bath fixing this way as well.

Hope this "clears" things up a bit.

Doremus

 

[mr rusty]

Temperature is a factor too. While I carefully get the developer temp correct, I don't worry if my fixer is a little on the cool side (as it often is in my darkroom in winter), but I check its clearing time before I use it to get a good idea of how long to fix for. 2x clearing time has always worked OK for me. cool fixer seems to work slower which I guess is to be expected.

 

[RattyMouse]

Learn how to do a clip test right! There are probably hundreds of posts here describing the process, and you have it wrong. So, to recap:

First put a drop of fixer on a scrap of film. Wait 30 seconds THEN immerse the entire scrap in a tray/dish/tank of fixer. Start timing and agitate. Make sure the lighting is good so you can observe the results. When the rest of the film is so clear that you can no longer tell the difference between where you put the drop and the surrounding area, that is "clear." And, the time it took to reach "clear" from when you immersed the entire scrap and began timing is the "clearing time."

If you do the above, you won't have any problem seeing when the film clears and finding the right clearing time.

Do a clearing test in fresh fix for every film you use to find a "benchmark" time for determining fixer exhaustion. You can't use one film to determine the clearing time for another film. The "benchmark time" is ONLY for deciding when to toss your fixer. Discard fixer when the clearing time for a given film is twice that in fresh fixer.

To use clearing time to determine the correct MINIMUM fixing time for film, you must do a clip test immediately before processing in the fixer you are planning to use with the film you are planning on fixing. Note that the clearing time in used fixer will be longer than that in fresh fix. Then, use this time as a guide for determining MINIMUM fixing time.

Now we can talk about fixing times: First, although Ilford and others specify at least twice the clearing time as a guide for proper fixing time, many others recommend THREE times the clearing time for a proper fix. Yet others advocate using at least the manufacturer's minimum fixing time and no shorter, regardless of the clearing time.

So, what do I do in light of all this? First, since film is coated on a waterproof base and moderately longer fixing times will do no harm, I fix longer than the MINIMUM time. I also use two-bath fixing whenever possible. My rule-of-thumb is: THREE times the clearing time plus 10% (for fixer exhaustion during processing) or the minimum manufacturer's recommended time, whichever is LONGER. This time is divided equally between two baths for me, but you can use single-bath fixing this way as well.

Hope this "clears" things up a bit.

Doremus

Thank you. Your method is so simple, it's brilliant! I wish I had thought of that.

I am not using the clip test to determine the amount of fixing time, only to find out if my fixer is still OK to use. In that case, I do not need to use more than one film to test it. I have the fresh fixer time using Acros 100 and will use that as this batch of fixer ages.

Thank you for your help!

 

[removed account4]

hi rattymouse

if you re-use your fixer you should do the clip test often
the more you use the fixer the less active it is
and the more time it takes to clear your film ...

have fun !
john

 

[Simonh82]

Learn how to do a clip test right! There are probably hundreds of posts here describing the process, and you have it wrong. So, to recap:

First put a drop of fixer on a scrap of film. Wait 30 seconds THEN immerse the entire scrap in a tray/dish/tank of fixer. Start timing and agitate. Make sure the lighting is good so you can observe the results. When the rest of the film is so clear that you can no longer tell the difference between where you put the drop and the surrounding area, that is "clear." And, the time it took to reach "clear" from when you immersed the entire scrap and began timing is the "clearing time."

Agreed that this is really good advice. If you do a clip test just by putting a spot on some film, you will think it has cleared much quicker than if you do the above test. I've found there is a faintly detectable difference, long after you would think that the film had 'cleared' using the simple method.

 

[Doremus Scudder]

Thank you. Your method is so simple, it's brilliant! I wish I had thought of that.

I am not using the clip test to determine the amount of fixing time...

Well, you should, as I outlined above! This is the best and easiest test to find proper fixing time, so why not use it? Peace of mind is worth the bit of effort.

...only to find out if my fixer is still OK to use. In that case, I do not need to use more than one film to test it.

You probably can get away with this, but I would play it safe and use the film I'm fixing for the exhaustion tests. Different films may react differently to fixer exhaustion, meaning that the fix may reach exhaustion for one film before another. Maybe one of the more knowledgeable chemists here will confirm or deny this.

Best,

Doremus

 

[Jaf-Photo]

I used to do clip clearing tests, but I think it's quite unnessesary now.

For B&W I use T-MAX fixer, which is very consistent. It does four rolls per litre of working solution without a problem, and it does turn colour when it's exhausted.

For C41 the fixer lasts longer than the developer, so I just change all the chems when the developer is gone.

No nasty surprises yet.

 

[RattyMouse]

I used to do clip clearing tests, but I think it's quite unnessesary now.

For B&W I use T-MAX fixer, which is very consistent. It does four rolls per litre of working solution without a problem, and it does turn colour when it's exhausted.

For C41 the fixer lasts longer than the developer, so I just change all the chems when the developer is gone.

No nasty surprises yet.

4 rolls per liter?? That's it?

 

[RattyMouse]

Well, you should, as I outlined above! This is the best and easiest test to find proper fixing time, so why not use it? Peace of mind is worth the bit of effort.




You probably can get away with this, but I would play it safe and use the film I'm fixing for the exhaustion tests. Different films may react differently to fixer exhaustion, meaning that the fix may reach exhaustion for one film before another. Maybe one of the more knowledgeable chemists here will confirm or deny this.

Best,

Doremus

I can't use the clip test to determine proper fixing time for every film because I do not have clearing times available for all films! I just made up a fresh batch of fixer and did the clip test for Acros 100. I've not processed a bunch of Acros 100 and so have no clear times for Delta 3200, HP5, etc....



It's not possible for me to establish the proper clearing times for all these films.

Besides, i over fix with time anyway. I fix for 6 mins regardless of film.

 

[pdeeh]

I can't use the clip test to determine proper fixing time for every film because I do not have clearing times available for all films! I just made up a fresh batch of fixer and did the clip test for Acros 100. I've not processed a bunch of Acros 100 and so have no clear times for Delta 3200, HP5, etc...

That's what leaders are good for ...

 

[Doremus Scudder]

I can't use the clip test to determine proper fixing time for every film because I do not have clearing times available for all films! I just made up a fresh batch of fixer and did the clip test for Acros 100. I've not processed a bunch of Acros 100 and so have no clear times for Delta 3200, HP5, etc....

It's not possible for me to establish the proper clearing times for all these films.

Besides, i over fix with time anyway. I fix for 6 mins regardless of film.

I really don't understand. If you have the film and are shooting it, just use the leader for the clip test for roll films, or clip a bit of the end of a 120 roll before loading it onto the reel for a clip test! It doesn't matter if it's been exposed to light or not. If you are shooting sheet film, then sacrifice a sheet. Keep it for future clip tests and just clip small strips from the non-code-notched end as you go. One sheet will give you multiple test strips. There's really NO excuse.

You can and should establish clearing times for each film you use. I do a clip test almost every time I develop, even when using the fixer one-shot, just to make sure everything is functioning properly. I certainly do a clip test before running an additional batch through used fixer!

Doremus

 

[Jaf-Photo]

4 rolls per liter?? That's it?

Sorry, I left out information. 4 rolls at the shortest fixing time. You could do 10-15 rolls if you want, but then both fixing time and washing time will be longer. I even used to do one shot fixers, but that became too expensive when I started shooting more film.

It still only equates to 4-5 bottles of fixer per year, so it's not very expensive.

 

[GarageBoy]

Ruh roh, I've been fixing for 5 minutes and just calling it a day and I lost track of how many rolls have gone through it. How do I check for deficient fixing?

 

[MattKing]

See what a current clip test tells you. If it still clears quickly, guess at the number of rolls. If the guess isn't too many rolls, and the clip test is still quick, you'll be fine.
There is also a chemical check you can do. I believe Photographers' Formulary sells the materials.
Or you could re-fix them all in fresh fix (keeping track this time), and then do the washaid and wash sequence again.