Bubble Trouble

I'm having trouble with occasional small bubbles on my film and wonder if anyone can suggest a remedy? The films involved are PanF+, FP4+ and Delta 400. The bubbles appear as small spots of underdeveloped emulsion maybe 1-2mm in diameter. They may appear only once or twice on each film but they have a habit of ruining whatever frame they're on.

1. Prewash 3min at 23 degreesC. Vigorous agitation for first 30 seconds.Tank banged hard 3 times after agitation.
2. D-76 1:1, constant agitation for first minute then every 30 seconds. Tank banged hard 3 times after each agitation.
3.Stop Bath, 1 minute agitation twice, banging the tank again.
4. Fix, Agitate 3 times over 3 minutes, banging again.

I'm using a Jobo 1501 tank with two 120 format films on the one spiral as per Jobo instructions. I don't really know what else I can do, I'm just about breaking the tank when I bang it.

Any help appreciated,
Matt.

I have hade the same problem. Now I use a Cibachrome motor to rotate the tank during developing. First 30 sec agitation, then three bangs, then rotation with a shift of direction every 60 sec. And banging the tank a couple of times when turning from one direction to the other. My negatives have never been better.

Good luck! j-fr

www.j-fr.dk

I only ask this just in case.

The tank has amounts for rotation and inversion just check you are using enough liquid for inversion.

Thanks Jens and Steve,
yes my next step is to go to rotary processing but it's a little more complicated than I'd like right now. I'm living away from home for a year and processing in my bathroom.

I should have stated in my original post that I'm using enough chemicals to almost completely fill the tank (600ml) as I was advised by someone else that leaving too much air in the tank can cause uneven development even if the chemicals cover the film.

Could it be the close pitch of the spirals with the JOBO tanks that's causing the problem?

Matt, your agitation technique has worked fine for my 35mm work, except my stainless steel tanks can't break even with the quite hard banging they get. Some plastic tanks certainly can break when sharply rapped on a counter top. I sometimes use a prewash with PhotoFlo added, but don't have air bubbles even without. When using fewer rolls than fill a tank, I add empty reels to keep the reels from banging during inversion, but only use enough chemicals to cover the film.

Mattg said:

I'm having trouble with occasional small bubbles on my film and wonder if anyone can suggest a remedy?

1. Prewash 3min at 23 degreesC.Matt.

Click to expand...

Film manufacturers may incorporate surfactants in the film itself in which case a pre-wash can be creating the problem you are trying to avoid. Major film manufacturers like Kodak do not recommend a pre-wash for their films.

My guess would be that froth is being generated by the vigorous agitation during the pre-wash, and clinging tenaciously to the film during development. (Those little bubbles just don't want to die!)

I do the same 3-bang routine (remembering the old "Knock three times" song almost every time) on the edge of my SS tanks (straight down is supposed to not work as well). We'd need to call them "Raps", now, though.

I am sure you'll get more replies as to what you should do but one thing which might help is telling us if you have always had a "bubble problem" or if not, then when did it start. I get the impression, perhaps wrongly, from the way you write that this hasn't been a problem from the outset. If it hasn't always been a problem then the key is "what's changed"

I too have Jobo tanks and have used inversion agitation on a similar if less rigorous banging routine than you and haven't had a problem. The only substantial difference between your method and mine is that mine has never involved a pre-wash.

I know how frustrating it is to be told that others use similar methods and don't have a problem which is what I seem to be saying, I know.

I am sure that the cause of your problem is out there and somebody or bodies will hit on the answer.

Best of luck.

pentaxuser

I always prewash my films. I use gentle agitation, that’s relative to others I’ve observed, in a plastic tank. These days I use a partial stand development routine, and I usually forget to bang or rap the tank. I don’t get bubbles.
Interesting thread me thinks.

The only time I ever suffered air bells or bubbles in an inversion tank, I aggitated during prewash. I've never found a bubble after pouring in the prewash and banging the tank afterwards and just leave it sit. I have no idea why on that one occasion I decided to change my routine, but it ruined a couple of rolls of the Tennessee River at Scottsborough and some of the Walls of Jericho.

K.

Thanks everyone.

Gerald:
I have only recently started using a prewash because of a persistent problem with uneven development. It was an intermitent problem and would only ever appear on one or two frames. Since going to the prewash I haven't had this problem. I know Ilford also do not recommend a prewash and yet most of the advice I see here and elsewhere suggests using one.

Ralph:
Yes that makes sense; given the very small size of the bubbles, they could easily stay on the film during the short time between prewash and development.

I will try "rapping" the edge of my tank rather than just the bottom which is what I've been doing to date.

PentaxUser: What's changed? Pretty much everything.

I've moved overseas and am now processing in a bathroom with different tanks (now Jobo, then Patterson). I am now using a prewash which seems to have cured some uneven development problems.

The bubbles have been a problem since I moved but have been a problem both with and without a prewash.

Kobin:
Very useful I will try this also.


Okay so next time I develop a film (tomorrow) I will change these things:

1. I will still give a prewash but without any agitation.
2. Bang edge of tank rather than bottom.
3. After the first 15 seconds of development, during the minute continuous agitation, I will also "rap" the tank once or twice just to make sure there are no bubbles at this crucial stage.

Thanks again for the suggestions, I'll let you know how it goes.

Matt, the problem may also be because of a difference in your water supply. There is much lime in my water, so I use distilled water to mix chemicals and for a final wash. Tap water seems to work OK for the prewash.

Water supply could be the problem but my bet is on the agitation during prewash or not rapping the edge of the tank.

Sorry no results today, I did process one roll of Delta 400 but it's so humid here in Incheon that after 4 hours hanging the film was still very tacky so I couldn't inspect it properly. Will let you know what I find tomorrow.

I've had a look at the film I developed yesterday on a light table and can't see any bubbles. I don't know which change in technique made the difference but it doesn't really matter to me, it's easy to incorporate all three into my routine.

I'll post back if the problem crops up again.
Thanks again, Matt.