How do YOU pre-soak?

MattKing

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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.
 
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pbromaghin

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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?
 
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pbromaghin

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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.
 
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pbromaghin

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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?
 

Photosandpotatoes

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Illuminating thread! I’ve been wondering how others do this.


What’s the difference between presoak and pre wash? When would you do one vs the other?
 

Craig

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

No, because that is intended to remove the residual fixer compounds. At the stage of processing you are contemplating, there isn't anything for it to work on.

Thinking of the foaming, are you making sure the tanks are scrupulously clean so there is no wetting agent carry over, and are you also observing the capacity? D76 can only be replenished a finite amount and there is a hard limit to the amount of film that can go through a replentished solution before it must be dumped.
 

Vaughn

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Illuminating thread! I’ve been wondering how others do this.



What’s the difference between presoak and pre wash? When would you do one vs the other?

I'm trying to previsualize a presoak and/or a prewash. Prior to using developer (the 'pre' part) I suppose one would soak the emulsion just to get it swelled, wet, and ready. And one would wash the emulsion to remove any water soluable additives to the emulsion. It seems it would be difficult not to have a soak also be a wash.
 
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pbromaghin

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It’s only halfway through the replenishment routine and none of my tanks or reels have been touched by photoflo in over 5 years. So we’re safe there.
 

runswithsizzers

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I've been pre-washing evey b&w negative film with temperature-adjusted tap water for 60 seconds with constant agitation. However, I have been experiencing some uneven development with 120 film, only, so I should probably try skipping the pre-wash to see if that helps. Either that, or doubling my pre-wash time.

I have been very lucky and never had a frothy brew.
I would consider myself very unlucky if I was not able to enjoy a frothy brew at least once a week. And unless things have changed since I was last there, you have some very good frothy brews on your side of the Atlantic. ;-)
 

Sirius Glass

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Illuminating thread! I’ve been wondering how others do this.



What’s the difference between presoak and pre wash? When would you do one vs the other?

Both are the same operation. So there are no differences.
 
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Illuminating thread! I’ve been wondering how others do this.



What’s the difference between presoak and pre wash? When would you do one vs the other?
Well, it's nit-picky semantics actually, but here's the distinction. You would soak film to wet the emulsion with water and let it absorb as much as it can so that the gelatin was in its fully hydrated state before developing. Some think this helps with evenness; it definitely helps keeping sheet film from sticking together. Pre-soaking before development is not really necessary if the film can be immersed quickly and evenly in the developer.

A pre-wash would be to remove something from the emulsion before development, in this case, the surfactant that the manufacturer puts in the emulsion to aid in developer penetration and even development with machine processing. The idea is to remove that so it won't cause foaming by building up in the replenished developer. Sure, the emulsion gets soaked and saturated with water in the process, like a pre-soak, but that's not the goal; the goal is to remove something.

Removing something from the emulsion, like a surfactant, will likely take longer than it would take for the emulsion to swell completely with water, and might need some agitation to help the process, hence my recommendation to use a longer pre-wash than a soak and to agitate as well.

See, there are some differences

Hope that answers your question.

Doremus
 

David Lyga

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I have some Kodak ImageLink microfilm. If I presoak, there is no emulsion left. This is the only film that seems to do that. - David Lyga
 

MCB18

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I do pre-soak as most of my films have any-Hal dyes that come off in the dev if you don’t. It doesn’t do any harm but I still try and avoid it.
 

Maris

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I don't pre-soak I pre-wash: at least four changes of water with agitation with the aim being to remove every soluble molecule from the exposed film before development. This is done to prevent those soluble molecules accumulating in my replenished Xtol. The process seems to work since my present batch of Xtol has been working predictably from 2021 when it was first mixed until today. Replenishment at 90ml per film plus a slight increase in development time allows for the little bit of water carry over from the pre-washing stage.
 

Photosandpotatoes

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This is super detailed and very helpful! Thank you for taking the time to explain.
 

Samu

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I normally don't presoak for black and white film, except in summer, if the room temperature is very high. We don't usually have air con here in apartments in Europe. For color films, I do presoak for 3-5 minutes, and for color paper, for about a minute or so. I use just tap water.
 

koraks

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for color paper

RA4 color paper has a surfactant added to it. Hence, pre-washing the paper serves no purpose. Pre-soaking may help if you otherwise have problems with unevenness. Keep in mind that color paper is by its nature not intended to be pre-anythinged. Which doesn't mean you can't - just that you'd be solving a problem you introduced on your own end that's not inherent to the product as such.
 

DeletedAcct1

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Hi Peter,
I'd suggest against pre-soaking. Ilford has put a wetting agent in the emulsion for a reason.
 

Kino

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Stearman SP 8x10 daylight trays require pre-soak. - Yes, 1 min.
Jobo Expert tanks - generally yes. 3-5 min.
Everything else - maybe yes, maybe no. At least 1 min if I do a pre-wash to remove brightly colored anti-halation dyes; depends on stock.

I see no difference in results either way...
 

Vaughn

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Hi Peter,
... Ilford has put a wetting agent in the emulsion for a reason.

Ilford wanted to create bubble baths out of developer replenishment systems?

All much of a muchness, as my ex use to say. The time it takes me to soak the emulsion before development (and usually one change of water...so a semi-predevelopment wash) is not significant in my workflow as I am also working on other steps of the process while the drum is turning for the 5 minutes pre-development soak/wash. I'll continue since it also serves a valuable service (getting drum and film up to temp) and is recommended by the German engineers who tested their product (Jobo Expert Drums) with multiple companies' films.

And after several decades of developing sheet film and using printing processes that can easily show uneveness in film development, I am happy with my results.
 

Samu

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Uneven developing is the problem why I pre-soak. Otherwise I will have streaks due to uneven developing in drums. Also, the paper in rolls is often curled the "wrong" way, and is not always easy to get evenly to fit against the walls of the drum. To counteract this problem, I presoak and use a bigger amount of chemistry than minimally needed. As I replenish, the amount of chemistry used is not an issue.
 

mshchem

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Yeah, I go back to the old Kodak Ektacolor Professional fiber base color paper that was still, just barely available when I started, it required presoak per Kodak's instructions. Same was true even when using RA-4 with Kodak's drum processors.

I pre-soak when developing in tubes like the Jobo 1526 and 28xx series tubes. Brings up the temperature and smooths out the processing.

Certainly no continuous roll paper processors use a pre-wet, no need for an extra step.
 
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