Of Rotaries, XTOL Replenished, and Foam

[m00dawg]

Figured this might be a good place to ask since I'd imagine some fellow LF folks might be using XTOL replenished since dev'ing sheets can require a lot of chemicals. In fact that's the very reason I started down the path of using XTOL-R. The problem I'm having is I'm getting foam which I haven't quite figured out how to mitigate/remove so I can pour most of the solution back into my replenishment bottle. It wasn't as much of an issue when using an accordion bottle but is a problem with glass.

I went with a glass bottle since it has a narrow neck to make pouring easier and also I don't have to fiddle as much with the accordion. Instead my plan was to just put in my 75ml of stock then top it off with the used developer all the way up to the top to avoid an air gap. Trouble is, because of that foam, I'm left with foam at the top. It settles down after about 24 hours but then to fully remove the air gap I have to go back and add a tiny bit more developer.

I tried using my funnels that have a screen on the bottom, but the bubbles seem to either go right through or get created by pouring the dev in. I thought about maybe using a coffee filter but wasn't sure if that was pulling out any chemicals I want in the solution?

I suspect this would be less of a problem with hand inversions over rotary processing which I'm now doing. I know I can hand process with a 2500 but my rotary setup along with XTOL-R has been pretty consistent and it also lets me be a little lazy :P

Long story short, anyone have suggestions on how to tame XTOL foam?

[koraks]

If you poor developer in until the bottle is full, the foam siply overflows, no? That's what I do with RA4 developer which I replenish and which also foams like crazy.

[m00dawg]

If you poor developer in until the bottle is full, the foam siply overflows, no? That's what I do with RA4 developer which I replenish and which also foams like crazy.

I thought about that, but then the foam gets everywhere haha and I have to worry about cleaning it up. Hmm I suppose I could put the glass jar in the sink if it'll sit flat then wipe it down. I was thinking of maybe trying to skim the foam off the developer in the beaker somehow before I pour it back in.

[pau3]

Are you getting foam with all your films or only for some specific brands? In any case, a thorough pre-rinse may help to get rid
of any wetting agents the films may have incorporated in their emulsions. Try to perform it in two steps: pre-rinse, dump the water, pre-rinse again.

[m00dawg]

Hmm that's a good point.

All my films, in varying degrees cause it. It seems to be worse with sheet films than roll films. I'm guessing the end wings on the 2500 spool contribute to more agitation there perhaps. I feel like my XTOL is foaming more than it did though I haven't changed anything. Thinking it has to do with it starting to become seasoned.

I used to be huge into pre-rinsing but I recall reading, I think in Ilford docs, NOT to pre-rinse when using a rotary though it didn't say why. In hand tanks I always pre-rinsed. Seems like that's better for the developer as well since it doesn't pick up those wetting agents or anti-halation layers.

EDIT: After reading through this post about pre-soaking I think I might go ahead and give it a go. I haven't had any unevenness by not pre-soaking for any films _except_ a few sheets from the new CHS ii which had uneven development. They had a line where the developer was sitting in the tank while I was pouring it in before I put it on the rotary (wasn't but a few seconds). Pouring the dev out of the tank after CHS ii has a bright yellow color, almost the color of Ilford stop bath. I assume that is the anti-halation layer but maybe pre-soaking may help with it.

Worth a shot anyway if it will help with the foam.

[koraks]

Do you use wetting agent in your tank? Do you thoroughly rinse the tank after use? Maybe it's just carryover from the previously processed roll.

And yes, I pour back the developer over the sink so the foam can easily be washed away. Rinse the outside of the bottle after capping it and dry it with a towel.

[Pere Casals]

Long story short, anyone have suggestions on how to tame XTOL foam?

I'd use a LIQUID FOOD GRADE DEFOAMER



This is silicone based so mostly inert, it is used at very, very low concentrations (2 ppm, parts per million, 0.002ml per 1L, buy the smallest possible bottle) with impressive effects. Check that it has no interference with development, buy I guess it won't, at all. Disolve 1ml in 1L for the intermediate dilution, then add 2ml of the dilution per 1L of developer.

These additives are used in many situations, from burger fries (to remove oil foam) to Spa resorts.

I use that proffesionally.

Silicone is dimethylpolysiloxane, it looks McDonald's uses it in some countries

https://yourquestions.mcdonalds.ca/a...-conditioner-/
https://web.archive.org/web/20190305...-conditioner-/

____________________


Anyway as you use a rotary I'd use regular Xtol one shot, you won't have much waste.

Rotary mixes a lot of air in the chem, this is not good to keep the used developer, anyway using a defoamer may be good to avoid problems.

[John Foxe Sheets]

I'd use a LIQUID FOOD GRADE DEFOAMER



This is silicone based so mostly inert, it is used at very, very low concentrations (2 ppm, parts per million, 0.002ml per 1L, buy the smallest possible bottle) with impressive effects. Check that it has no interference with development, buy I guess it won't, at all. Disolve 1ml in 1L for the intermediate dilution, then add 2ml of the dilution per 1L of developer.

Hi Pere, This is great information. I purchased a commercial pool & hot tub defoamer (not the same brand you're using - I can't find that brand locally and Amazon won't ship it fast enough) and added 2 PPM to my MaxPyro developer. It seems to have improved the situation, but I still see uneven development in the form of bubbles on some of my batch of negatives. I'm processing Ilford Delta 100 5x7 film in a 3006 Expert Drum at ~36 RPM on my CPP-2, and I'm doing a 5:00 presoak and then a ~1:00 rinse prior to the development. (The rinse is to try to remove any foam that might be left-over from the presoak's removal of the Ilford wetting agent that is on the film.) Do you use the defoamer only with the developer? Or do you also use it with any of your other baths? Do you have any other suggestions that might help?

Thank you very much,
John

[Pere Casals]

Hi Pere, This is great information. I purchased a commercial pool & hot tub defoamer (not the same brand you're using - I can't find that brand locally and Amazon won't ship it fast enough) and added 2 PPM to my MaxPyro developer. It seems to have improved the situation, but I still see uneven development in the form of bubbles on some of my batch of negatives. I'm processing Ilford Delta 100 5x7 film in a 3006 Expert Drum at ~36 RPM on my CPP-2, and I'm doing a 5:00 presoak and then a ~1:00 rinse prior to the development. (The rinse is to try to remove any foam that might be left-over from the presoak's removal of the Ilford wetting agent that is on the film.) Do you use the defoamer only with the developer? Or do you also use it with any of your other baths? Do you have any other suggestions that might help?

Thank you very much,
John

IMHO you may use it with any bath as it is a pretty inert chem, it's just silicone. The 2 parts per million dose is very low to have any side effect.

I've used it sometimes in the darkroom, but normally I use it a lot in my (non photography) job. My guess is that E6 chem may include it, it is a very, very common solution in the industry for when foam in a problem: cheap, very low dose, inert, highly effective and not toxic, it has all virtudes. It is used from motor oil to frites.


McDonald's frites have it

https://yourquestions.mcdonalds.ca/a...-conditioner-/
https://web.archive.org/web/20190305...-conditioner-/

I'd like to know if it is included in the chewing gum to prevent people dropping foam from mouth

___

Seriously, just use it when foam is a problem for you.

I still see uneven development in the form of bubbles on some of my batch of negatives.

Please post a crop of the scan with the uneven development.

Ilford datasheet says: "A pre-rinse is not recommended as it can lead to uneven processing." https://www.silverprint.co.uk/wp-con.../Delta-100.pdf

Pre-rinse removes surfactants in the emulsion that are important for an even development, still many people are happy with pre-soak, you do a long enough pre-soak to not have problems, but anyway I'd try without pre-soak.

What it delivers problems is a too short pre-soak, because it removes the surfactants and emulsion is left with a non uniform wetting. Most moderm films are designed to not require pre-soaking.



Regards,
Pere

[John Foxe Sheets]

IMHO you may use it with any bath as it is a pretty inert chem, it's just silicone. The 2 parts per million dose is very low to have any side effect.

Thanks - I'll try it in all baths.

Please post a crop of the scan with the uneven development.

Here are two photos that show the issue. One is a closeup of the other. (Note that I adjusted the scans to make the problem more visible.)

Ilford datasheet says: "A pre-rinse is not recommended as it can lead to uneven processing."

Thanks - I know. But they also say (elsewhere) that since Jobo recommends pre-rinse that you should do it and make sure you do it for at least 5:00 - which is what I'm doing. FWIW, I tried without a pre-rinse and the problem was even worse, but that was without the defoaming agent...

Thanks,
John