How do YOU pre-soak?

[MattKing]

Partial quote..



I don't understand that bit myself, so hopefully I am on the correct course.


At the end of dev, fix and wash, I transfer the loaded film spiral to a separate bowl of fresh water with a tiny amount of wetting agent. My wetting agent does not go anywhere near the tank. Then the emptied spiral is given a thorough good wash.

If you are adding wetting agent to the tank for the final rinse is, there a possibility that the tank is assumed to be clean after all the rinsing,and not being thoroughly washed clean of the wetting agent?
So you end up with the developer wetting agent, plus the residue wetting agent from the previous final rinse.

I have been very lucky and never had a frothy brew.

The OP is referencing the trace amounts of surfactant that are added by the manufacturer to certain film emulsions in order to ensure even wetting at the time of development - most likely to avoid problems with some commercial dip and dunk lines.

 

[pbromaghin]

It seems you want to know how you should pre-soak, not how we do it. So might I be so bold:

You need to remove the surfactants from the film to both prevent accumulation in your replenished developer and prevent uneven development. Not fully removing enough of the surfactants will cause uneven development. Really, you are after a pre-wash, not a pre-soak (the terms are not interchangeable).

So, you need to proceed like your were washing film. A fill-and-dump regime if you're using tanks or a running-water or multi-tray regime if you're using sheet fill seems necessary to me. A longer time than what is needed to saturate the emulsion would also seem in order.

I'd start with a five-minute soak with changes of water and gentle, continuous agitation. Tap water is just fine; if you can wash your film with it, you can pre-soak in it as well. Use the same temperature as the rest of your process.

If you still have foaming problems with your developer or uneven development problems after that, then you'll need to extend the pre-wash.

Best,

Doremus

Hmmmm. Very perceptive. I hadn't thought of pre-soak and pre-wash as 2 different processes, but that an assembly of APUG wisdom would give clues on how to go about it.

I wonder, would it be worthwhile to include Harmon Washaid, normally used on papers?

 

[pbromaghin]

Partial quote..

I don't understand that bit myself, so hopefully I am on the correct course.

Any debate concerning the benefit or lack thereof with presoak usually ends up going round and round, with arguments between minds that have been firmly made up and may end in insults with one of the participants melting down and leaving after having the mods delete all record of his ever having been here.

 

[pbromaghin]

I wonder, would it be worthwhile to include Harmon Washaid, normally used on papers?

I just realized how dumb this would be. Washing off one substance and replacing it with another?