cleaning colour negatives

[nwilkins]

I just got three rolls of 120 portra 400 back from the local lab and the negatives are covered in fingerprints and surface smudges/streaks. Any advice on how to clean them up would be appreciated. I've never run into this problem before so I don't know how to clean colour negs. thanks!

 

[Kevin Caulfield]

Isopropanol usually works quite well.

 

[polyglot]

Isopropanol often contains a lot of water and will swell the emulsion, making it fragile. Try some PEC film cleaner or similar, which is mostly methanol and butyl ester. No water.

 

[Worker 11811]

I also prefer PEC-12.
You can use isopropyl in a pinch but make sure it is 92% alcohol, not 70%. If you look in the store, there are two kinds. Make sure you get the "high test" stuff.

Whichever you use, PEC-12 or alcohol, use sparingly. Work carefully so as not to scratch.

 

[polyglot]

Or if you're really hardcore, trichloroethane


(No, I'm not recommending that. It works insanely well and used to be the default approach, the only drawback being that chlorinated organic compounds will kill you slowly but surely).

 

[Athiril]

PEC-12 leaves deposits when it dries (spray some on something clear, let it dry, it's horrid), and is quite pricey. Even with the tiny drop it recommends.

It's a good solvent, but not as a final cleaner. If you use PEC-12, put the film back through some wash and let it dry to get rid of the PEC-12, though disposable soft gloves and gentle rubbing in the solution of a wetting agent is preferable imho to begin with. Mirasol 2000 Antistatic is good for colour, because it contains anti-bacterial/anti-fungal and anti-static agent.

Also do not use PEC-12 to clean developer tar off things (like it says it can on the bottle), it dries so damn fast, that it deposits it back onto other things, and in many cases it cannot be redissolved by anything, we have a big dark room sink with stains all over it from cleaning with PEC-12.

It cannot be revmoved by more PEC-12, HCl, Bleach, scrubbing, you name it.


I sincerely do not recommend this product.

 

[RPC]

At the lab I work at when we were running film we never used PEC-12 to clean film for the reasons Athiril said. We did use it to clean prints without problems. For film we used cleaners designed specifically for film or anti-static cleaning cloths (great for removing dust). These usually wouldn't remove fingerprints, however. To do that the film was run back through some of the processing chemicals! I don't know exactly which ones because I didn't do it but it worked.

 

[Chan Tran]

Or if you're really hardcore, trichloroethane


(No, I'm not recommending that. It works insanely well and used to be the default approach, the only drawback being that chlorinated organic compounds will kill you slowly but surely).

Yeah right! I had exposed to that stuff a lot when I was younger working on printing presses. Now my hands dried out badly every winter. Yeah it's baaaad stuff but it works very well as a solvent for just about anything.

 

[DREW WILEY]

Amen to PEC-12. But there was a minor reason tricholoro got pulled from the film foodchain. It had the
nasty habit of killing people from time to time.

 

[DREW WILEY]

If you need to step it up a notch, pure methyl alchohol works superbly, but it's very expensive, and don't confuse this with garden-variety denatured, which has quite a bit of added water, and is otherwise mainly isopropyl. The tech industries use quite a bit of methyl for fussy cleaning work.

 

[Athiril]

At the lab I work at when we were running film we never used PEC-12 to clean film for the reasons Athiril said. We did use it to clean prints without problems. For film we used cleaners designed specifically for film or anti-static cleaning cloths (great for removing dust). These usually wouldn't remove fingerprints, however. To do that the film was run back through some of the processing chemicals! I don't know exactly which ones because I didn't do it but it worked.

Oh yeah, forgot to mention, it cleans tar and other stuff off RA-4 prints very well, that otherwise don't want to come off.

But I do not recommend it for getting tar and other stuff off developing equipment and racks. It'll dry and deposit onto something else.

 

[nwilkins]

okay thanks for the replies everyone. looks like I might try something like the mirasol to start with.