Fixing times when re-using Ilford Rapid Fixer

[Shangheye]

I have set myself up successfully with a dip and dunk process for my 4x5 LF development. I'm using Ilford FP4 rated at box speed and using DDx (1+4) as developer, followed by Stop bath, and then Ilford Rapid Fixer. I am using a rule of thumb of 10% extra development time for every 8 sheets put through the developer (seems to be working...). What should I do for the fixer? I am assuming that because I have used stop bath I am depleting the Fixer more slowly? Anyway, should I be applying the same increase in time for fixing? How can I test that the fixing time is correct? Would be interested how other do it, since Fixer seems to be the main cost at the moment for me (I have been throwing it away to be safe....but its just too costly for that)

Rgds,

K

 

[BWGirl]

Hi!
Well, I am not so clinical when I fix, but I always fix my film for a minimum of 4 minutes, and most commonly 5 minutes. Here is a link to the fact sheet for the Rapid Fix:
http://www.ilfordphoto.com/Webfiles/2006130218312091.pdf

I do not think it matters whether you use an actual stop bath or a water stop bath. I could be wrong, but I think the purpose of the stop bath is just to stop the developer from... developing.

 

[Ian Grant]

A stop-bath or a good water rinse will prolong the life of the fixer, and film fixer has a greater capacity, films are more tolerant of higher silver content compared to papers, particularly fibre based.

Ian

 

[Mahler_one]

If you are using RC paper then one would suspect the fixer time would be relatively short. With PF rapid TF4 fixer one simply uses 1 minute in the fixer...the less time needed to fix, the less time needed to wash....

Ed

 

[Ian Grant]

If you are using RC paper then one would suspect the fixer time would be relatively short. With PF rapid TF4 fixer one simply uses 1 minute in the fixer...the less time needed to fix, the less time needed to wash....
Ed

It's not as simple as that, if you're re-using the fixer particularly with films the times increase.

Very few people will be using TF-4, most will be using rapid fixers like the OP. Paper has lower silver content than film but it is also less tolerant of higher silver levels in part or well used fixer, the old adage is fix films for at least twice the clearing time, so if your film hasn't quite cleared you know to fix for much longer.

Typically film fixer is still fine with a silver content of 5gms/litre, paper fix shouldn't be used above about 2gms/litre.

Ian

 

[Shangheye]

Ian, Can I use the silver content of a film to calculate the 5gms/litre you suggest above? If I know how much silver there is in a 4x5 film and assume that 50% is lost, and I have the volume of the fixer (1litre...I should be able to do the calculation as an approximation right?...Now just to have someone tell me how much silver there is in a 4x5 film sheet :rolleyes:

 

[BradS]

The simple, general rule of thumb is to drop a piece of exposed film - the film leader from a roll of 35mm for example - into the fixer and note how long it takes to clear. Double the clearing time and you should be pretty good. Dump the fixer when the clearing time exceeds the mfgr's recommended time by a factor of two.

My personal experience with Ilford rapid fixer has been that it doesn't hold up well to multiple re-use. In other words, its performance degrades rather quickly after the five or so rolls per liter of working solution.

 

[Ian Grant]

Just to elaborate on Brads figures.

I've just ditched a litre of Ilford Rapid Fixer, at a quick estimate it fixed 20+ rolls of 120 (Tmax400, HP5 & FP4), and over 50 5x4's plus a few rolls of 35mm, it was stored in a glass bottle and the silver plated out on the sides and was filtered out occasionally. I topped it up every now and again with a bit of fresh fix. The fixer was still working well when I changed it, albeit a little slower.

I'm sorry Brad but your figures aren't relevant, look at Ilford's own recommended figures which are 24 rolls of 36mm 36ex per litre of working solution (unreplenished), that mirrors my own experience over the last 40 years. See page 2 of the link given by BWgirl.

Ian

 

[BradS]

Well, that's interesting Ian. I guess, our personal experiences differ. I am left to wonder as to the possible reasons for such a large discrepancy. Brainstorming, I can only come up with two possible explanations:

1) I mix all pre-packaged chemistry with the local tap water which is quite hard and...

2) I do not tolerate rapid fixer that takes longer than about five minutes to clear.

 

[Ian Grant]

Brad, I replenish my fixer so thats why I get quite a high throughput.

The water here is very hard, it ruins a kettle first time you put tap water in it, so we have to use bottled water in the kettle and to drink. But I make my fix up with tap water and have no problems at all with it.

My films usually take less than about 3 minutes to clear and I fix until the last trace of the Tmax 100 purple/pink dye disappears, about 5 or 6 minutes sometimes a bit longer. I've just been getting my films ready to take back to the UK for printing and there are 24 rolls of 120, 8 rolls of 35mm and 73 sheets of 5x4 that's all fixed using one 500ml bottle of Rapid Fix. As I said that's pretty much the throughput recommended by Ilford themselves.

Ian

 

[BradS]

There is absolutely no way you can fix that much film in 500ml of working solution and still be clearing tmax in under five minutes....no way...

 

[Ian Grant]

There is absolutely no way you can fix that much film in 500ml of working solution and still be clearing tmax in under five minutes....no way...

Who said 500ml of working solution

I used a litre of working solution & replenished it that's 2½ litres of fix at 1+4.

Ian

 

[BradS]

ah-ha! yes. Now, that is entirely plausible and completely consistent with mine own observations. Case closed...let's go have a beer down at the pub.