Agitation with Paterson Tanks

[ericdan]

I've been getting marks on my negatives from air bubbles during development.
I've used different agitation techniques. Infinity motion or inversion every minute then bang the tank on a hard surface but I still get bubbles.
Especially with inversion I notice that the developer foams a lot.
How do you guys avoid bubble marks on your film during development?

 

[CMoore]

Does "Burping" the lid, after you get it tight, make any difference.?
I have heard of this problem, but have never experienced it. When i invert a Paterson, i do it gently, in a "big" arch, and leave it be for a few seconds before i reverse the direction.
Other than that.....i don't know.

 

[Alan W]

I've been using Patterson tanks for well over 20 years and have never had any marks on my negatives.I have never inverted the tank-in fact I never used the old inversion cap at all.I fill the tank,tap the bottom a couple of times and use the agitator-ten inversions every minute.What developer are you using?

 

[Nodda Duma]

Pre-soak with water for five minutes, tapping the Paterson tank on the counter when you've filled the tank.

Tap the tank on the counter when you first fill with developer.

 

[Hatchetman]

I don't think there's anything more irritating than a great photo/exposure with an air bubble in the sky.

 

[darkroommike]

This is what I have my students do. Fill the Super System 4 tank, three hard raps, start time, constant agitation for first 30 seconds. Then three inversions every 30 seconds with a gentler bump, rotate tank 90 degrees and every 30 seconds repeat. We are using 35mm film and D76 1+1, developing times tend to be rather looooooonnnnnnnnggggggg with this combo, 14 min at 68 deg. F., but no air bells. and the developer does foam, a lot. I used to do Tmax and Tri-X with Tmax developer in the older System 4 tanks, and used the agitation rod instead since those darn things had a tendency to leak.

 

[mshchem]

I never had a problem. I did the inversion with rotation. This creates a bit of a swirl, this is how I was taught by a guru. Every 30 seconds for 3 inversions, 1 good rap on the counter when you set it back on the counter. I used HC-110, D-76 and XTOL 1:1. I never noticed foaming? I got my first Paterson tank around 1971. I always use distilled water.
Best Regards Mike.

 

[WilmarcoImaging]

I use a Paterson tank for C-41 and black and white with inversion agitation. No bubbles. I use a pre-soak and I attribute no bubbles to the pre-soak. Tapping the tank on the sink/counter also helps IMO.

Some people report bubbles from using acetic stop bath, likely at excessive strength (concentration). I had bouts of black dots in the past, and I attributed this to the stop bath. For black and white I use a plain water stop bath, two changes of water with vigorous agitation, about 30 seconds total. No black dots anymore. So the suggestion is to weaken stop bath, if you are using it. Or delete it and replace it with a plain water stop.