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kevin klein
05-30-2007, 02:56 PM
Can Chrome Alum be used in developer?

I tried plain Alum but it would not go into solution with the developer.

Tom Hoskinson
05-30-2007, 04:29 PM
Can Chrome Alum be used in developer?

I tried plain Alum but it would not go into solution with the developer.

What film are you working with? Most modern films already have hardened emulsions.

Some Efke films have rather soft emusions. I shoot a lot of Efke 25 and Efke 100 and I've never found it necessary to use a hardener - either pre-development or post development.

The only film I've pre-hardened was Kodak ektachrome E4 false color IR film. I pre-hardened it in a formaldehyde hardener (Kodak SH-5) before high temperature processing it in E6 chemistry.

kevin klein
05-31-2007, 01:24 PM
I am using my own emulsion.

narigas2006
06-21-2007, 08:33 AM
maybe i am wrong, but chrom allum wont harden the film straight away. maybe paraformaldehide would do a better job.

Photo Engineer
06-21-2007, 09:59 AM
Paraformaldehyde decomposes into formaldehyde in solution. It can fog film if mixed with the developer.

Chrome alum is a slow hardener and should not be added to the developer either.

If you must harden, either use a hardener and wash before the developer or after the developer.

PE