Supe old kpdak fixer unopened

[mexipike]

Someone gave me this giant box of Kodak fixer it is unopened but surely at least five years old. Any thoughts if it's any good?

 

[MattKing]

Pour out some and check how it smells.

If it is really sulfurous, that isn't good.

Opening the box and viewing the cubitainer inside to check for sulfur deposits would also be a good idea. Just be careful to preserve as much integrity of the box as possible, because it serves as the holding frame for the cubitainer, and if the fix is okay, you will want to tape the box back up.

Also, try a clearing test on a T-grain film. If the clearing time is short, that is good.

 

[L Gebhardt]

My guess is you will find precipitate if it's over 5 years old. I recently found a few boxes that are newer than that one and they were bad. Rapid fixer does not keep that well.

 

[Terry Christian]

Like the others have said: if it smells sulfurous, it is bad. If it smells sharp and acrid, it is still good. By all means test it.

 

[Rudeofus]

Most non hardening rapid fixers start as a mix of Ammonium Thiosulfate and Ammonium Sulfite, and possibly some compounds (Metabisulfite, Acetic Acid, Boric Acid) to adjust pH and buffering. As these fixers pick up aerial Oxygen, first the Sulfite is converted to the more acidic Sulfate. Once the Sulfite is gone, Oxygen attacks the Thiosulfate which also turns into something more acidic. Once pH goes below 4.5, the remaining Thiosulfate will disintegrate into Sulfite and Sulfur. The Sulfite in acidic solution will give you the smell, and the Sulfur is the yellow precipitate so many here have observed.

What happens if you add Sulfite to this mix? First of all, Sulfite is a mild alkali, so you bring pH back into a region where Sulfite plus Sulfur form Thiosulfate again. Secondly you add Sulfite which again protects the Thiosulfate from oxidation. Perfect? Sounds like it, but it isn't. The Sulfate created during storage remains in there, and it slows down fixation, both because of ionic strength reasons and because Sulfate deswells your emulsion. You also don't know whether all the Sulfur went back into solution, so you may bring some particles into your emulsion where they stay and may cause trouble later on. You've also most likely added Sodium Sulfite instead of Ammonium Sulfite, and Sodium ions make a fixer slower than Ammonium ions. You may have also lost some Thiosulfate for good when it became oxidized, so your fixer may be more dilute than you think, lowering both fixer speed and capacity.

When you state "it's perfect", can you confirm than clearing time was close to what the original product gives you?

 

[Photo Engineer]

Note that the box says "A" on it. This implies there is a "B" solution as well. You may only have 1/2 of the fix unless "B" is inside the "A" package. Tread carefully here. The "A" part may work just fine or it may eventually leave stains. It may be totally fine and you will have no worries at all.

PE

 

[MattKing]

Note that the box says "A" on it. This implies there is a "B" solution as well. You may only have 1/2 of the fix unless "B" is inside the "A" package. Tread carefully here. The "A" part may work just fine or it may eventually leave stains. It may be totally fine and you will have no worries at all.

PE

Ron:

In this case the "A" solution is all you need. The "B" solution is hardener, it is optional, and in fact is sold separately when you buy the Kodak Rapid Fixer in this size of package.

I've been buying it recently in the smaller size package where the "B" solution comes with it whether you want it or not. I want it because I prefer to use it after using sepia toner on my prints, and it is difficult to obtain separately in reasonable sizes.

 

[Photo Engineer]

Thanks Matt. I am aware of that. That is why I qualified my answer. Perhaps I was too vague. Sorry and thanks.


PE