# Drying Negatives



## darin3200 (Jan 2, 2006)

I have a roll of Tmax 100 that has water spots on it. I put the roll in some distilled water and used my fingers to get off the excess, after this the roll was put up to dry in a shower. The problem is I still have water spots.

Suggestions?


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## JonK (Jan 2, 2006)

There's a fluid you can get to add to the water which will aid in drying it spot free....darned if I can remember the name of it tho.
anybody?

Ah-ha! - *Photo-Flo!*
Give it a try...if that doesn't work I'd invest in a good pair of negative squeegees.


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## terri (Jan 2, 2006)

I fear the squeegees for use on negatives. Too easy to get scratches. Use the Photo-Flo or LFN and hang 'em. If you want, use your fingers to lightly squeegee them. 

You might still see a few water spots, but it's unlikely they'll affect the prints.


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## PlasticSpanner (Jan 2, 2006)

I never seem to have any problems with water spots! 

I use Photo-Flo to rinse the negs whilst still on the reel and shake excess water off (vigorously) before removing them & hanging to dry.

I have tried squegee (which does scratch ) and my fingers (risks leaving finger prints/patterns if you stop) to remove water and have found the above method the best.


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## JonK (Jan 2, 2006)

I was thinking back to when I used to do darkroom....and yeh I remember just using  my fingers and photo-flo. seemed to do the trick.


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## Hertz van Rental (Jan 3, 2006)

darin3200 said:
			
		

> I have a roll of Tmax 100 that has water spots on it. I put the roll in some distilled water and used my fingers to get off the excess, after this the roll was put up to dry in a shower. The problem is I still have water spots.


Water spots are nearly always caused by chemicals that are present in the wash water being deposited on the neg when the water evaporates.
If the water forms into droplets and they are allowed to remain when the neg dries then the deposits can be concentrated enough to leave marks.
White marks are usually Calcium Carbonate - the stuff that causes lime scale (the furring up of your kettle for example).
Calcium salts are always present in tap water to some degree. The concentration is expressed in 'hardness'. Hard water contains a lot, soft water very little. People who live in soft water areas rarely have a problem with drying marks.
These marks can be cleaned off but because they take the form of crystals or powder there is a danger of scratching.
There should be no chemicals dissolved in distilled water so if you still get water marks something is wrong.
The water could be just 'de-ionized' which is not the same things as distilled and usually still contains chemicals.
If the distilled water has been used before to wash negs then it may suffer from a build-up of chemicals.
If the negs have been washed in an inefficient manner (putting the tank under the tap and leaving it is a good example) then there may still be a considerable amount of processing chemicals in it and on it and these will cause drying marks, the final rinse not being enough to get rid of them.
Always wash films by using changes of water. Fill the tank and invert several times before discarding. If you repeat this process 10 times the residual chemicals in the film will be down to less than 0.1%. 12 washes and the residual is below 0.025% which is archival quality.
Leaving the tank under a running tap does not work as water pressure in the tank causes the fresh water to bounce off the top and not get to the film.
Force washing works but as there can be a lot of grit and rust in tap water there is a high risk of scratching. I've seen it happen.
The wash water should should also be at around 20C to avoid micro-reticulation. Using the 'water change' method allows you to control this.
User a proper wetting agent in the final rinse, and use the correct dilution.
Too much wetting agent will leave a residue on the film. Too little has no effect.
The wetting agent breaks down the surface tension of the water and disperses it to aid drying and minimise water marks.
DO NOT use detergents like washing up liquid. These are long chain molecules made from fats or oil and will leave a sticky greasy residue on the film. I have had arguments with people insisting that these detergents work and don't leave a deposit - but the dilutions they use are not sufficient to break down the surface tension of the water so they don't actually do anything. (If anyone wishes to argue with this, try checking out the chemistry. And if it did work, Kodak would use washing up liquid)
If you do not have any Photo Flo then ethylene glycol (car antifreeze) will work in a pinch. It's chemically very similar.
Carefully check the film during drying to make sure there are no water droplets formed. If they form on the emulsion (dull) side they are really bad news as they can distort the emulsion as they dry.
Water droplets on either side of the film are best removed by carefully licking them off with the tip of your tongue. Honestly. It does work.


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