Kodak Rapid Fix Part"A" yellow precipitate

spoolman · Sep 6, 2012

I just checked on a package of Kodak rapid fix A&B to mix for a film processing session and the Part "A" bottle had a yellow precipitate in it. Is this sulfurization and if I poured off the clear liquid would be useable or is it kaput.

Doug

Gerald C Koch · Sep 6, 2012

Yes it is sulfurization and no it is no longer usable.

SkipA · Sep 6, 2012

What about the part B, Gerald? I've got a half full large bottle of Part B that I never used. It's about 10 years old. It says it contains sulfuric acid. It's totally clear and looks fine. Does it go bad?

Does anyone have any idea what the percentage of sulfuric acid is in it? I usually use Kodak F-24 fixer (recipe from Anchell, Darkroom Cookbook). If I wanted to make it a hardening fixer, could I add some of that part B? How much per liter?

Are there any other good uses for Kodak Fixer Part B? Can it be used in place of concentrated sulfuric acid to make dichromate bleach?

Mike Wilde · Sep 6, 2012

The part B I am familiar with is a much small bottle, compared to the Part A one. I inheritted a collection of part B bottles from a closed down photo club community darkroom. I believe it is the hardener component, and a lot of people did not want hardended prints (screwes up the ability to toner them easily, I think).

Donate to HHW is the route I took.

I did not belive it was only sulfuric, and that I why I disposed of them.

Gerald C Koch · Sep 6, 2012

If part A is bad what would you use part B for? I suppose you could use it to make a hardening fixer. Howeever the trend has been away from using hardening fixers even for paper. Paart B contains sulfuric acid and an aluminum salt.

Vaughn · Sep 6, 2012

I got a lot of those (bottles with the yellow gunk). It would be great to be able to reverse the reaction that happened, but I have never heard of one.

SkipA · Sep 6, 2012

Gerald C Koch said:
If part A is bad what would you use part B for? I suppose you could use it to make a hardening fixer. Howeever the trend has been away from using hardening fixers even for paper. Paart B contains sulfuric acid and an aluminum salt.

I don't have part A. That was the OP, not me. I have only part B, and I thought I was clear with my question about it and what use I contemplated for it. I figured you might have some thoughts on it, since you are a chemist, but that's ok. Thanks anyway.

I don't really care what the trends are, btw. I have never used hardening fixers, ever, (which is why I still have this part B), but it happens that there are some situations where they are useful, such as when working with delicate emulsions.

SkipA · Sep 6, 2012

Mike Wilde said:
The part B I am familiar with is a much small bottle, compared to the Part A one.

It used to be available in large bottles. The part B bottle I have is 72 ounces, 2.13 liters, CAT 173 3013. Part A was much larger, but I don't recall now.

MattKing · Sep 6, 2012

That Part B is pretty strong stuff - it is the reason that there are hazmat charges involved when the smaller packages of Kodak Rapid Fixer are shipped.

Don't drop or spill it!

IIRC, PE has stated that it is only designed for use with Kodak Rapid Fix - it won't work properly with others.

Gerald C Koch · Sep 6, 2012

Be careful with dilute solutions of sulfuric acid. If you get any on your clothes there will be holes after you wash them.

SkipA · Sep 6, 2012

I use battery acid today for making potassium dichromate bleach (Kodak R9 bleach for use with D94/95 b&w reversal film processing). I was just wondering if the part B could be used in place of the battery acid, but if it contains anything other than sulfuric acid, I guess not.

Vaughn · Sep 6, 2012

SkipA said:
It used to be available in large bottles. The part B bottle I have is 72 ounces, 2.13 liters, CAT 173 3013. Part A was much larger, but I don't recall now.

We use to buy Part B in 5 gallon cubetainers. Lost a pair of Levis to Part B many years ago.

jerrybro · Sep 7, 2012

I filtered the yellow stuff and use it, works fine for me .

Gerald C Koch · Sep 8, 2012

jerrybro said:
I filtered the yellow stuff and use it, works fine for me .

Fine if you're not concerned with archival permanence or any other kind of permanence.

Gerald C Koch · Sep 8, 2012

An acidified thiosulfate solution is unstable and will rapidly precipitate elemental sulfur. To prevent this sodium sulfite is added to fixing baths. This chemical reacts with the nascent sulfur to form thiosulfate. However once all the sulfite has been used up the fixer will rapidly sulfurize. Once this point is reached there is no point in trying to save the bath. Trying to do so endangers you film or prints. On is being penny wise and pound foolish.

Kodak Rapid Fix Part"A" yellow precipitate

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