Plastic reel agitation issues

[michaelbothager]

Hello all

Two questions about issues when developing in a Paterson Super System 4 tank with 2 reels and 120 film, using inversion agitation.

a) Surge (cavitation) marks, do they always appear on the same edge of the film, like at the upper edge of the reel?

b) Air bubbles, do they also occur on the lower reel with inversion agitation? Since the agitation is the air rushing through the developer, I imagine that the air bubbles can get stuck on both reels.


All the best to everyone.
Michael

 

[MattKing]

I've never had issues with surge marks with my Paterson Super System 4 tank with 2 reels and 120 film, although I am usually using the AP/Samigon/Arista Premium clone versions of those reels - the ones with the wider loading ramps.
And in years of use, I've only observed air bell problems once. I think, that the air bells came from the top of the top reel, but I'm not absolutely sure.
FWIW:
1) I always fill the tank with the suggested amount - 1 litre - of developer. I do that even if I'm developing a single film. I use replenished developer, so there is no concern with waste;
2) during the development stage, I start with 30 seconds of continuous, alternating direction rotary agitation. For the rest of the development stage, I use inversion agitation of 5 seconds every 30 seconds. My agitation movement involves both inversion and rotation and is sufficiently energetic that I can feel and hear the developer gurgling and tumbling through the reels.
Our water here is quite soft, and I am careful to ensure that my reels are clean - I never put Photoflo on my reels.

 

[Alan9940]

IMO, Paterson's recommendations for total solution volume are too low. For example, they recommend 290ml for the single roll 35mm tank; I typically use about 400ml. Try using more developer volume and see if that helps.

 

[Sirius Glass]

Air bells can be eliminated by thumping the tank on a hard rubber pad several times each new chemical is poured in AND filling the tank to completely cover the top film.