Stop Bath Time Extension

[Bob Carnie]

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]

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]

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