Beginner Cleaning B&W Negatives

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Hi There
Took the plunge and just started a B&W film dev and printing course at my local college.

Loving it! Real hands on stuff!

Developed my first ever reel the other day (under instruction) - Ilford Delta 100. Left in drying cabinet over night.

Did some contact sheets and test strips last night. Some negs had some whitestains (chalk deposits - one "benefit" from living on the South Downs). I had followed the teacher very carefully and rinsed etc, after the dev, fix and stop processing and ran the film between my fingers, squeegee style - before drying.

Any tips for getting rid of these marks on the current negs and also how to prevent future staining..?

Cheers
 
When I rinse my negs I run tap water through the dev tank until they're sufficiently washed, and then I empty the tap water out and fill it up with filtered water (from one of those Brita filter jugs) and leave them in there for a minute or so before I take them out and hang them. My thinking is that all of the tap water with the minerals on it has been flushed by the filtered water and hopefully stops any marks. Not sure if my thinking is correct or not but I've had no issue with marks yet :)

I know a lot of people use wetting agents in their final rinse, to stop drying marks appearing on their film. I've never used it myself (and I'n not sure if it would help with chalk marks??) but I'm sure a lot of the F&C members use it, and will have better answers for you after they've woken up :D
 
Yep, distilled or filtered water as a final rinse. If I don't do that I tend to get marks. I use photoflo. Not sure how much it helps TBH.
 
I always found that wiping the dried negatives with a microfibre cloth clears away any fingerprints/marks. Lay the negatives on the cloth then fold the rest over the top and gently rub over the negative.
 
1. Hard water.
There are two types of hardness of water - temporary and permanent. Temporary hardness is caused by calcium carbonate in the water, and is cured by boiling - you get the residue left in kettles where the chemicals are precipitated out. Permanent hardness is caused by other calcium compounds, and isn't fixed by boiling.

So, if you get lime scale in your kettle, you'll have less hard water if you use water that has been boiled as the final rinse. "Water that has been boiled" though - not boiling water.

2. Water droplets.
Water forms droplets due to surface tension. Wetting agents reduce surface tension, and make the droplets smaller - and increase the ease of running off the film.

3. Water (purified)
There are various ways of purifying water. In broad terms, there are three classes of impurity - inorganic chemicals (as in hard water, above), organic chemicals (as in benzene, found in some French mineral waters as a news report reminded us some years ago), and living microorganisms. Purified water is water that has been purified, but no guarantee is given by the name as to the process. All should remove the lime scale; only "water for injections" is supposedly guaranteed to be distilled and clear of all foreign matter.

Hence
A final rinse in purified water, or boiled water if no other is available, which has some wetting agent in it should reduce the chances of water marks when drying.

If you avoid hanging the film vertically, but hang at an angle, the water has a shorter path to the edges and so is less likely to leave a drop to dry on the image area of the film.

Other methods involve finally rinsing in an alcohol based liquid that will both dry rapidly and not leave a deposit. Agfa made Drysonal for this purpose.

If you want to remove the marks, gentle wiping or rewashing should do it. Beware of damage to the emulsion (non shiny) side of the film, if the marks are there.
 
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Thanks All - Would any of the above be worth trying even after 1 week of drying? Or is it too late?
 
I always found that wiping the dried negatives with a microfibre cloth clears away any fingerprints/marks. Lay the negatives on the cloth then fold the rest over the top and gently rub over the negative.

I can vouch for this method. Steve developed some B&W for me and the negs were spotless.
 
It's not too late to remove marks. A gentle wipe with a dust free clean cloth should be fine.
 
I've never heard of a film being harmed by Fairy liquid, but I don't use it myself because I don't know what's actually in it. Clearly it contains some colouring agents and perfumes apart from what actually does the cleaning. If it is basically a soap, that can precipitate calcium from hard water (vide the white scum that you get in wash basins in hard water areas).

Wetting agents (speaking generally, not in a specific photographic context) are either ionic or nonionic in action (never mind what this means :)) and the ionic variety can cause precipitation to occur. Ilford specifically state that Ifotol (their wetting agent) is nonionic.

Given the relative cheapness of wetting agent compared to the value of the film, I prefer to err on the side of caution.

And do note my opening remark. I'm acting from caution not from specific information.
 
That sounds like a fair enough scientific explanation to me without going back to the days of Chemistry at school!
I didn't realise that wetting agent was as low a price as it is, so maybe I might get a bottle, cautionary as you say.

Adam
 
I don't actually know what it costs! At a drop a time I haven't bought any in years :)
 
Thank again all!
1. Tried the microfibre cloth technique on a few non-important negs. Worked a treat
2. Will try filtered water next, if not successful will try #1 then #3
3. Wetting agent and hanging negs at an angle. Worth a shot too...
 
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