Cleaning fixer residue

[AndrewB]

I've just started shooting black and white film again, and have been getting my chemicals ready for developing the film after a gap of 4 years. However, after dumping the contents of my old fixer bottle, there was a white/greenish residue in the inside.
Is there an effective way of getting rid of this residue, other than scrubbing it?

Thanks,
Andrew

 

[Gerald C Koch]

B B's, gravel, or whatever, and a lot of shaking and soapy water.

Uncooked rice also works well.

 

[Maris]

The residue in the fixer bottle is almost certainly a tenacious precipitate of sulphur. The only good sulphur solvent I've used (under laboratory conditions) is carbon disulphide. But don't try it. CS2 is appallingly vile and dangerous. Frankly, I'd get a brand new bottle rather than risk contaminating film or paper with minute, and hard to remove, flecks of sulphur.

 

[Sirius Glass]

Bar Keeper's Friend http://www.uline.com/BL_542/Bar-Kee...gclid=CJ3w-Lbp_8oCFQ8vaQodm3gJcQ&gclsrc=aw.ds

 

[Gerald C Koch]

The only good sulphur solvent I've used (under laboratory conditions) is carbon disulphide. But don't try it. CS2 is appallingly vile and dangerous. Frankly, I'd get a brand new bottle rather than risk contaminating film or paper with minute, and hard to remove, flecks of sulphur.

Carbon disulfide is considered to be moderately toxic. The usual route is by inhalation. It is very volatile and easily forms explosive mixtures with air. In this respect it is similar to ethyl ether. Commercial grades smell; well the best description is that they smell like farts. However the pure chemical has an ethereal odor that is not unpleasant.

+1 Bottles are not that expensive and buying new ones probably worthwhile.

 

[AndrewB]

I managed to remove most of the residue in the end by scraping it with a plastic spoon, and filling it with warm water and leaving it to stand, then dumping it out after a while.
However, I have ordered a new bottle for the fixer anyway.

 

[GRHazelton]

When I was a kid my Father, a PhD in chemical engineering, used carbon disulphide to disinfect tins of flour, etc, for my Mother. He was very careful, given its toxicity and flammability. He'd put perhaps a teaspoon in a five pound tin of flour OUTSIDE in the sun and wait an hour or two for the stuff to evaporate, dissipate, and kill possible moth larvae and eggs. I wish I could get some today.... Q#$#$%^&$%^^@ pantry moths! The pheromone traps help, but not against the larvae!

 

[Rudeofus]

I have a small glass bottle in which a batch of fixer went bad, the usual thing, Sulfur precipitating out and getting stuck to bottom and wall. Into this bottle I then put Potassium Sulfite solution, about 40% concentration. After a few days the whole Sulfur deposit was dissolved, the bottle looks like new.

I can not tell you whether a lower concentration of Sulfite will do the trick, but it's quite likely that you can use the much cheaper Sodium Sulfite. What you do need is patience, it will take a few days to clear up all the precipitate, but at least you can do it without dangerous chemicals.

 

[john_s]

I have a small glass bottle in which a batch of fixer went bad, the usual thing, Sulfur precipitating out and getting stuck to bottom and wall. Into this bottle I then put Potassium Sulfite solution, about 40% concentration. After a few days the whole Sulfur deposit was dissolved, the bottle looks like new.

I can not tell you whether a lower concentration of Sulfite will do the trick, but it's quite likely that you can use the much cheaper Sodium Sulfite. What you do need is patience, it will take a few days to clear up all the precipitate, but at least you can do it without dangerous chemicals.

This is the way to go. Scrubbing and scraping can be avoided if you use the right solvent. I discovered something along the same lines. I found it difficult to clean saucepans in which dried beans had been cooked for hours. I noticed that soaking in detergent (alkaline) seemed to make the deposit even worse, So, what is the opposite of alkaline? Acid. Enter a few spoons of vinegar, a 10 minute soak, and then it comes clean with a light brushing.

As Rudeofus probably knew, sulphite solution dissolves sulphur, one way of making thiosulphate.