Smoke film on negatives

[Papa Tango]

This morning, I processed four 120 rolls of FP4 and hung them in a forced air drying cabinet. All as usual. What was not usual is the small matter of the blower motor deciding it was time to burn out... :confused:

By the time I got back into the darkroom (running about three floors of house looking for the burning electrical smell) the dryer was shut down with a blown fuse. It had managed to deposit an ever-so-slight residue on the film.

My first inclination is to respool the film in the tank, wash for a few minutes, give a good soak in Photo Flo, and wash again. It occurs to me that this may or may not remove the residue, and the longer I deliberate over the matter the less likely I think that I am going to be for removing it.

Any suggestions?

 

[Photo Engineer]

Whatever you do, don't do anything that involves rubbing the film. Smokes for the most part are small pointy particles than can scratch things. They are also so tiny that they can get into gelatin particles.

IDK the solution but it will involve washing, no scrubbing or rubbing and trying to keep the particles from being imbibed.

Also, if there are organic 'rubber' type particles, beware that some solvents will merely soak them into the emulsion or support.

Sorry I can't help more.

PE

 

[ben-s]

If you've still got a bit of leader attached, you at least have something to test with...

As it's FP4, the emulsion should be reasonably tough - you could try moderately vigorous agitation in a detergent solution like photo-flo or another wetting agent.

Obviously, I haven't tried this, but it's probably something I'd try in the same situation...
Let us know how you get on.

 

[gainer]

I'm sure you would know if it was a case of insufficient fixing that just happened to coincide with the other mishap, but it's worth mentioning just in case the other was just a red herring.

 

[Papa Tango]

No Herring Please, Too Salty...

Nope Gainer, no red herrings in the darkroom--sardines either. I process all of my film to archival standards--hence the filtered air drying cabinet. You did get me to thinking though.

First thought was to run the film back through a dilute fix to take advantage of the detergent action of the thiophosphate. This was reconsidered in light of the selenium treatment that was done post fix. But the phosphate line of thinking made me consider sodium carbonate, which in dilute form might dissolve the residue and not affect the negative density through any solvent action. A little more thought and research is underway...

As all of the leader is still attached (film is still hanging in the dryer), I think that following Ben's suggestion for experimentation is a good one.

 

[Papa Tango]

Problem Solved!

The solution proposed by Crusingoose solved the issue. I also tried the carbonate and it more or less worked on the test strips cut from the leader, but the isopropyl alcohol was the clear winner in removing all traces of oily residue without any damage to the emulsion or substrate.

The rubbing alcohol was also used to clean the vinyl curtain of the drying closet and the interior of the dryer chassis. Luckily, the fan for the Arkay dryer is a common 120VAC muffin fan. One has been ordered and everything should be back to normal by Wednesday.

Thanks for the help!