Stop Bath Time Extension

Bob Carnie

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• Jan 10, 2006

• #1

This question is for the chemical guru's.

I have a need to extend my stop bath time to 1 1/2 minutes for fibre paper and sheet film .
Can anyone see a problem with 1 extra minute in an acid stop?

 

Gerald Koch

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• Jan 10, 2006

• #2

I see no reason why this should cause any problem. In fact, 1-1/2 minutes is more in line with what was used some years ago.

 

Photo Engineer

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• Jan 10, 2006

• #3

With 2% buffered or unbuffered acetic acid, the stopping reaction is complete within 30 seconds or less at 68 deg F or 20 deg C. This is in the emulsion itself.

The reaction takes a little longer in the paper base, but would not require over an additional 30 seconds IMHO.

PE