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kevin klein
05-23-2007, 03:34 PM
Took out a container of emulsion that was in the fridge two or three months, it had watery layer on top, and when melted and poured it had small chunks of stuff, looked like unmelted emulsion.

Photo Engineer
05-23-2007, 03:44 PM
That might be what it was, but it could be a big lump of fungus or mold. Don't you use a preservative? I use 10% thymol in isopropyl alcohol. I use about 1 drop per 100 ml of 10% gelatin.

PE

Kino
05-23-2007, 05:56 PM
Does mold or fungus have a speed effect? ;)

Photo Engineer
05-23-2007, 06:28 PM
Any growth in a photographic emulsion affects its ability to either spread satisfactorily or to harden well. This pretty much has prevented me personally from testing the other qualities of the emulsion. That and the often offensive odor kinda put me off as well as the look of the stuff.

I would think that the emulsion would fog due to loss of the protective colloid.

At Kodak we were encouraged to toss any spoiled materials.

PE

Vaughn
05-23-2007, 07:37 PM
Does mold or fungus have a speed effect? ;)

I had a batch of pigmented gelatin go bad on me, but I made carbon tissue with it anyway.

I learned that my prints can stink in more ways than one!:o

Vaughn

kevin klein
05-25-2007, 10:58 AM
I have not used any preservatives yet.

To be clear on the ratio of thymol, that would be the same as one drop 10%solution per 10.gm gelatin used?

Photo Engineer
05-25-2007, 12:11 PM
Yes.

PE

kevin klein
05-25-2007, 03:08 PM
Thank you.