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washing time with alkaline fixing

Posted: Sat Jun 08, 2019 7:56 am
by mska59IT
Hi, after reading the darkroom coobook I would try to use alkaline fixing. In the book it is said that with this fixing the washing times can be shorter. How much shorter percentage with FB card, eg 25%? Thank you

Re: washing time with alkaline fixing

Posted: Sat Jun 08, 2019 11:53 am
by sanchell
With FB paper in alkaline fixer, fix for two minutes, 1 minute in a first bath and 1 minute in a second bath with a 15-second drain between. When the first bath is exhausted I dump it and move the second bath to take its place and mix a fresh second bath. Note that 90% or more of fixing is done in the first bath (100% if the bath is freshly mixed). So the second 1-minute bath is insurance, especially as the 1st bath begins to age.

No HCA after fixing.

Wash in an archival washer (any washer that holds the prints in separate chambers) for 5 minutes. If you are washing in a tray limit yourself to 6-8 FB prints at a time and continuously leaf through them, bringing the bottom print to the top and flip it over once every 15 to 20 seconds. Prints should be kept with their backs facing backs and emulsion facing emulsion. Never wash prints with the emulsion facing the back of another print.

I recommend 10 minutes in a tray.

Re: washing time with alkaline fixing

Posted: Sat Jun 08, 2019 1:55 pm
by mska59IT
All really clear, many thanks.
Best regards

Mario

Re: washing time with alkaline fixing

Posted: Thu Aug 01, 2019 9:38 am
by tim.bowman
sanchell wrote: Sat Jun 08, 2019 11:53 am Prints should be kept with their backs facing backs and emulsion facing emulsion. Never wash prints with the emulsion facing the back of another print.
I read this everywhere, but I've never seen anyone explain why. What's so bad about having prints back to front?

Re: washing time with alkaline fixing

Posted: Mon Aug 05, 2019 10:37 am
by sanchell
It's really quite simple. What you want is to wash the chemistry out of the emulsion. The uncoated back of the paper (RC or Fiber) will stick to whatever side it is against. So, if the emulsion is facing the back, the emulsion will stick to the back and washing cannot occur. However, if the emulsion faces emulsion the two won't stick and washing of the emulsion can occur.

Even so, when washing several prints in a tray, even with running water, you should still shuffle the prints at least once every minute, making certain that emulsion is facing emulsion.

Re: washing time with alkaline fixing

Posted: Mon Aug 05, 2019 12:15 pm
by tim.bowman
That makes a lot of sense. Thank you for breaking it down for me!

-t