Re: Of Rotaries, XTOL Replenished, and Foam
Quote:
Originally Posted by
Pere Casals
I'd use a LIQUID FOOD GRADE DEFOAMER
Attachment 188447
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
Re: Of Rotaries, XTOL Replenished, and Foam
Quote:
Originally Posted by
John Foxe Sheets
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.
Quote:
Originally Posted by
John Foxe Sheets
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
2 Attachment(s)
Re: Of Rotaries, XTOL Replenished, and Foam
Quote:
Originally Posted by
Pere Casals
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.
Quote:
Originally Posted by
Pere Casals
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.)
Attachment 193728Attachment 193729
Quote:
Originally Posted by
Pere Casals
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
Re: Of Rotaries, XTOL Replenished, and Foam
Quote:
Originally Posted by
John Foxe Sheets
This problem is not from foam, I guess.
> Check if it is a bad fixing, fix it again in fresh fixer.
> Check if it is anti-halation layer that is not well removed https://www.photrio.com/forum/thread...9/#post-790211 , try with an hypo-clear bath with the sheet of the crop, or of add a table spoon
of sodium sulphite i the pre-soak and rinse before developer
Are you sure that this is from development ?
>>> I guess you know that the emulsion side has to face the inside of the tube, but it had to be mentioned.
1 Attachment(s)
Re: Of Rotaries, XTOL Replenished, and Foam
Quote:
Originally Posted by
Pere Casals
This problem is not from foam, I guess.
> Check if it is a bad fixing, fix it again in fresh fixer.
> Check if it is anti-halation layer that is not well removed
https://www.photrio.com/forum/thread...9/#post-790211 , try with an hypo-clear bath with the sheet of the crop, or of add a table spoon
of sodium sulphite i the pre-soak and rinse before developer
Are you sure that this is from development ?
>>> I guess you know that the emulsion side has to face the inside of the tube, but it had to be mentioned.
Thank you Pere. The process noted in the linked post is quite similar to mine. The only meaningful differences are no pre-soak, longer fix (I use two 2:00 fixes), no hypo-clear, and few other baths overall. I was using hypo-clear but I don't think it was making a difference. But I'd tried so many thing since then that I'm not 100% sure. I'll try again with fresh fix and then hypo-clear and see how things go. I'll let you know.
I'll be heading to a show tonight that I have a piece in, so it won't be until tomorrow... Here's the piece that's in the show:
Attachment 193736
One Bridge, Many Suns
2017 Solar Eclipse
Palladium print
Six sheets of 5x7 film, 18 exposures total
And yes, I know the emulsion goes on the inside. But thanks for asking - it never hurts to be sure!
Best regards,
John
Re: Of Rotaries, XTOL Replenished, and Foam
Quote:
Originally Posted by
John Foxe Sheets
And yes, I know the emulsion goes on the inside. But thanks for asking - it never hurts to be sure!
Me, I've even loaded sheets with emulsion facing holder's septum !! :)
1 Attachment(s)
Re: Of Rotaries, XTOL Replenished, and Foam
I'm happy to say my last test was a success. The key difference from my previous tests was that I stop dumping the chemistry as soon as the major flow is completed. I had been letting things trickle for too long. Here is a screen shot of the scans of the three negs I developed...
Attachment 193831
Thank you for your assistance, Pere!
Re: Of Rotaries, XTOL Replenished, and Foam