Drying Marks

greenspun.com : LUSENET : B&W Photo - Film & Processing : One Thread

Hi All, I have been having some problems with drying marks on B&W negs.

I am using Kodak Photoflo and allowing the negs to air dry. When printing I have noticed white streaks / drop marks on the print – on close examination of the neg there are no obvious marks or chemical residue.

Any suggestions on what could be causing this and what I can do to fix the neg that has already been affected and stop it from happening again?? Thanks David

-- David Jenkins (dhjphoto@hotmail.com), February 03, 2002

Answers

David, if you are not already doing so, I STRONGLY urge you to use only distilled water with your Photo-Flo. I also understand that Edwals 'Photo-Flo' works better, but have not tried it. As far as I know, you can't wash the stains out once you have them.

chris

-- Christian Harkness (chris.harkness@eudoramail.com), February 03, 2002.


Edwal's product, LFN low-foam wetting agent, is superior to Kodak's Photo-flo. I use two drops per liter of distilled water. A small bottle will last for several years.

-- Ed Buffaloe (edb@unblinkingeye.com), February 03, 2002.

I had a similar problem using Ilfotol wetting agent. The cure was to install a good water filter & stop using wetting agents.After washing the film I give it a few good shakes;whist still on the reel.The film is then forced air dried;still on the reel. Result..Clear negs,no marks.

-- Melvin (bramley@nanaimo.ark.com), February 03, 2002.

Melvin is going in the right direction, at least in adding a water filter. Check the mineral content of your water supply. Photo-flo cannot overcome the effects of excessively high hardness in your water, especially cold water that is warmed or heated, heating cold water tends to drive out calcium. Have you ever seen the white calcium deposits in at pot used for boiling water? Or give your negatives a good final rinse in distilled (mineral free) water with a little Photo-flo.

-- Howard Anderson (howardanderson40@yahoo.com), February 03, 2002.

Moderation questions? read the FAQ