Kodak Rapid Fixer, a few questions.

markbau · Mar 6, 2024

My only fixing setup for many years has been Ilford Hypam 1-4 with FB papers fixed for 1 minute. Today I purchased a package of Kodak Rapid Fixer which contains two bottles, I'm assuming Solution B is only added if you want a hardening fixer?

I've not used this fixer for probably 30 years, after reading the data sheet (KP116691C) I'm a bit confused.

It appears Kodak wants you to mix up the whole bottle in one go and get 3.8L or 19L of working strength fixer. Why do they not give you a dilution so you can just mix up enough for a session? Does anyone know what that dilution would be? I'm a bit dyslexic when it comes to math.

The mixing instructions are confusing, mixing for papers it gives instructions for making 3.8L or 19L. Yet in the fixing times it only gives one set of times.

In the paper fixing times section it says to fix "most non RC papers" for 10, TEN minutes when using the "one fixing bath method" How can this be called a rapid fixer when it takes 10 minutes to fix?

Anyone with any experience with this fixer please enlighten me.

koraks · Mar 6, 2024

markbau said:
It appears Kodak wants you to mix up the whole bottle in one go and get 3.8L or 19L of working strength fixer.

Depending on whether you buy the 1-gallon or 5-gallon pack.

markbau said:
The mixing instructions are confusing, mixing for papers it gives instructions for making 3.8L or 19L. Yet in the fixing times it only gives one set of times.

The working strength concentration is the same. One is a bigger box/pack than the other, that's all. They apparently also have/had a 20 gallon lab-oriented package size, and perhaps an intermediate-sized 3.5 gallon pack.
I assume what you buy today will mostly be the 1-gallon size.

markbau said:
Why do they not give you a dilution so you can just mix up enough for a session?

Because different powdered chemicals in the same bag don't mix homogeneously. Rapid fixer is typically ammonium thiosulfate, some sulfite, some bisulfite and perhaps some additional acid buffering stuff (maybe a sulfate), and probably an anti caking agent. If you take a bag of this stuff and run it through its typical life cycle of being filled, distributed, sitting in a shop/warehouse shelf, end-point logistics all the way into the end user's hands, you may find that all the sulfite has collected at the bottom with all the thiosulfate on top - or vice versa. There's absolutely no way to perfectly even out this uneven distribution with home tools/methods - although you can probably get plenty close enough "for government work". But this does mean that no sane manufacturer is going to give instructions for mixing a partial bag, because they can be 100% certain that the batches of fixer you mix from that same bag will all be different. Will that be a problem? I suspect most likely not. But "most likely not" generally doesn't cut it for the corporate legal dept.!

markbau said:
In the paper fixing times section it says to fix "most non RC papers" for 10, TEN minutes when using the "one fixing bath method" How can this be called a rapid fixer when it takes 10 minutes to fix?

That sounds excessive. I'd ignore that and just fix for 2-3 minutes tops.

mshchem · Mar 6, 2024

I use the hardener with fiber base prints that I dry on a drum dryer. The 5-10 minute fixing times are a relic. Kodak hasn't changed this recommendation since, well forever.

Ilford gives updated processing instructions for using their chemistry

Nicholas Lindan · Mar 6, 2024

Kodak Rapid Fixer is a liquid, and comes in a ~1 liter bottle to make 3.8 liters of working strength fix.

So, dilute a quantity of bottled fixer to 1:2.8 (2.8 = 3.8 - 1l) and you should be fine. Ditto the dilution for the hardener. I compound my own rapid fix w/o hardener and have never noticed its lack.

Powders can be divided without much problem. The 'separation anxiety' is largely overblown. I worked with a client who compounded powders for the medical industry. The powders were all mixed together and then dispensed into containers. There was no problem meeting FDA requirements for consistency.

Just give the bag of powdered chemistry a good random shake and everything should be OK. Unless, of course, your particular powder contains 1cm long crystals of thiosulfate. It's not like photographers haven't been dividing powders for a century or more. Kodak goes to great lengths to insure powder mixing consistency in the minimum of time, but then Kodak probably puts (well, put) the ingredients together in 1000lb mixing vats.

Opened packets/cans of powdered chemicals, when they absorb just the tiniest bit of humidity, will suck oxygen out of the air like there is no tomorrow. Be sure to store the remaining powder in a well sealed jar.

MattKing · Mar 6, 2024

I put the small bottle of Part B hardener aside. It can be mixed 1+13 to make a hardening bath, which is useful with some toning processes.
I then use as much of the concentrate in Part A as I need to make as much of the the working strength fixer I need.
Mixed 1+3 for film, and either 1 + 3 or 1 +9 for paper.
The time estimates vary, because they vary with what you are fixing, and Kodak put the information about that in the datasheets for the individual Kodak films and papers. For films, those range between 2 - 4 minutes.
I just use the times in the Ilford documentation that apply to Ilford Hypam - they work just as well.
I buy the 1 litre Kodak product when it is available at my local store. I buy Hypam in 5 litre size when I can't get the Kodak.
If you are mixing up the whole litre bottle, just make 4 litres of 1 +3 or 10 litres of 1 +9 - you can safely ignore the part of the instructions that take into account the small volume of Part B.

Doremus Scudder · Mar 6, 2024

I used to dilute Kodak Rapid Fix at 1+3, basically what Nicholas recommends above, or 1+7, to make whatever volumes of working solution I needed. The 1+7 dilution is similar to Ilford Rapid Fixer at 1+9 dilution. I never used the hardener. After getting tired of disposing of the little bottles of acidic hardener, I switched brands. (Typical Kodak poor marketing to home users of their chemicals...).

The recommendations for fixing times are antiquated and do not take into account the newer Ilford method of fixing for short times with stronger fixer (more poor marketing). The mixed solution without hardener is basically the same as Ilford Rapid Fixer or Hypam (without hardener). You can use corresponding times for corresponding dilutions and whatever method you use with the Ilford products.

Best,

Doremus

pentaxuser · Mar 6, 2024

Nicholas Lindan said:
Powders can be divided without much problem. The 'separation anxiety' is largely overblown. I worked with a client who compounded powders for the medical industry. The powders were all mixed together and then dispensed into containers. There was no problem meeting FDA requirements for consistency.

Just give the bag of powdered chemistry a good random shake and everything should be OK.

The last time anybody suggested the above, the aftermath was like the Battle of Gettysburg with perhaps a few less fatalities

pentaxuser

RalphLambrecht · Mar 6, 2024

koraks said:
Depending on whether you buy the 1-gallon or 5-gallon pack.

The working strength concentration is the same. One is a bigger box/pack than the other, that's all. They apparently also have/had a 20 gallon lab-oriented package size, and perhaps an intermediate-sized 3.5 gallon pack.
I assume what you buy today will mostly be the 1-gallon size.

Because different powdered chemicals in the same bag don't mix homogeneously. Rapid fixer is typically ammonium thiosulfate, some sulfite, some bisulfite and perhaps some additional acid buffering stuff (maybe a sulfate), and probably an anti caking agent. If you take a bag of this stuff and run it through its typical life cycle of being filled, distributed, sitting in a shop/warehouse shelf, end-point logistics all the way into the end user's hands, you may find that all the sulfite has collected at the bottom with all the thiosulfate on top - or vice versa. There's absolutely no way to perfectly even out this uneven distribution with home tools/methods - although you can probably get plenty close enough "for government work". But this does mean that no sane manufacturer is going to give instructions for mixing a partial bag, because they can be 100% certain that the batches of fixer you mix from that same bag will all be different. Will that be a problem? I suspect most likely not. But "most likely not" generally doesn't cut it for the corporate legal dept.!

That sounds excessive. I'd ignore that and just fix for 2-3 minutes tops.

I agree. 10-minute fixing is excessive. You would have to wash forever to get the fixer out ofthe paper fibers. In a 1+4 working strength, 1-2 minutes should do the job. I use the 2-bath fixing method for 90s in the first and 60s in the second bath.

albada · Mar 6, 2024

Nicholas Lindan said:
Powders can be divided without much problem. The 'separation anxiety' is largely overblown. I worked with a client who compounded powders for the medical industry. The powders were all mixed together and then dispensed into containers. There was no problem meeting FDA requirements for consistency.
Just give the bag of powdered chemistry a good random shake and everything should be OK.

Thanks for mentioning your experience with that medical client.
Years ago, I had a conversation with PE (Ron Mowrey) about this question. He discouraged me from dividing a mixed powder. However, it was pointed out to me (I don't recall by whom) that fixing and paper development are done to completion, so being a little off in a chemical won't hurt, so dividing mixed powder is acceptable for those uses. But not for film development, because that is not done to completion, so being a little off could affect the images.

FYI, here's a thread that says "don't separate": Mixing from two-part powder
This thread emphasizes that mixing powders is counterintuitive and difficult.

Mark

mshchem · Mar 7, 2024

You use a riffle splitter to do a proper job of dividing powders, made in many sizes. Powders need to be free flowing. In previous life I used a lot of these.

Anon Ymous · Mar 7, 2024

mshchem said:
... In previous life I used a lot of these.
View attachment 364727

Looks like you baked cakes?

What About Bob · Mar 7, 2024

mshchem said:
You use a riffle splitter to do a proper job of dividing powders, made in many sizes. Powders need to be free flowing. In previous life I used a lot of these.
View attachment 364727

Meatloaf pans!

mshchem · Mar 7, 2024

What About Bob said:
Meatloaf pans!

These are standard pans for these devices. Cost a crapload more. I like the idea of meatloaf though

markbau · Mar 8, 2024

Thanks for all of the replies. So I just want to confirm if I mix 1:3 I can fix for 1 minute using the standard Ilford procedure?

laser · Mar 8, 2024

If you post the label I'll take a look at it or send to makingKODAKfilm [at] yahoo.com In olden times I wrote and later approved the chemical labels.

Film dilution used to be 1:3, paper 1:7. Part B is hardenier. If you want a non-hardening ammonium thiosulfate fixer don't add the hardener.

markbau · Mar 12, 2024

Here is the label, I won't be using the hardener.

Kodak Rapid Fixer, a few questions.

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