Air bubbles at edge of frames causing uneven development

[Photo Engineer]

As I said, both are closely related and consist of bubbles. But, look at a stream flowing outside in the open. It has "foam" or "bubbles" on the surface. The water in a water treatment pland does as well. I doubt if there are any purposely added sequestering or wetting agents added, but they foam. Shake a capped container of tap water and you get "bubbles" or "foam". It is a natural event made more prevalent by man's additions to the environment.

It happens. Surfactants can make it worse.

Tapping can help. Try it on a bottle of shaken water (about 1/2 full).

PE

 

[GLS]

I would suspect residual surfactant on the reels from prior sessions.

I don't think so. I have not used a traditional wetting agent for some time now, and always thoroughly clean the tank and reels after each session.

I wonder if I could add some IPA to the developer (rather than Ilfotol) to discourage bubble formation, but I suspect this is probably not a good idea and may well have unintended effects on the development. @Photo Engineer do you have any experience regarding this latter point?

 

[Photo Engineer]

Good IPA and other low MW alcohols have no significant effect on emulsions but do reduce bubbles.

PE

 

[GLS]

OK thanks. Another experiment to try then.

 

[GLS]

So, an update on this issue:

I just tried a Pyrocat-HD development (of some Rollei IR 400) but using a 5:95 mixture of IPA:water instead of just water to make up the working solution, and also reverting back to a 600 mL total volume for good measure. Otherwise I kept my development regime the same as in the OP.

On inspecting the drying negs I'm happy to report I see absolutely no trace of the problem, and it doesn't seem to have introduced any detrimental effects I can discern. Another win for IPA

One word of warning to those who may wish to try this however: I have found that mixing IPA and water creates a non-trivial exotherm. My water was initially at 22 C, but upon mixing it 570:30 with the IPA the temperature went up to 24 C, which necessitated me adjusting the development time accordingly. Just something to be aware of. Makes the process a bit more fiddly, but presumably in the future if I started at 20 C and mixed I would end up in the ballpark of 22 C.

 

[Sirius Glass]

So, an update on this issue:

I just tried a Pyrocat-HD development (of some Rollei IR 400) but using a 5:95 mixture of IPA:water instead of just water to make up the working solution, and also reverting back to a 600 mL total volume for good measure. Otherwise I kept my development regime the same as in the OP.

On inspecting the drying negs I'm happy to report I see absolutely no trace of the problem, and it doesn't seem to have introduced any detrimental effects I can discern. Another win for IPA

One word of warning to those who may wish to try this however: I have found that mixing IPA and water creates a non-trivial exotherm. My water was initially at 22 C, but upon mixing it 570:30 with the IPA the temperature went up to 24 C, which necessitated me adjusting the development time accordingly. Just something to be aware of. Makes the process a bit more fiddly, but presumably in the future if I started at 20 C and mixed I would end up in the ballpark of 22 C.

Which beer are you adding? Interested reader want to know!

 

[GLS]

IPA = isopropyl alcohol

 

[Sirius Glass]

IPA = isopropyl alcohol

Now that IPA is just not good to drink! Why did you not say CH3CHOHCH3 instead?

 

[Vaughn]

You haven't seen some of my students agitating, then. Some of them you'd swear they were making cocktails. Excessive agitation generates bubbles.

Oh my, I take my double 120 reel SS tank and every 30 seconds act like I am tossing it over each shoulder a couple of times. I shoot that developer between the coiled film on the SS reels! Good exercise, too. But there is an inch of developer over the top of the reels -- perhaps that is why I never see such bubble damage. HC-110, Ilford Universal PQ, and PyrocatHD...a variety of film.

 

[GLS]

Oh my, I take my double 120 reel SS tank and every 30 seconds act like I am tossing it over each shoulder a couple of times. I shoot that developer between the coiled film on the SS reels! Good exercise, too. But there is an inch of developer over the top of the reels -- perhaps that is why I never see such bubble damage. HC-110, Ilford Universal PQ, and PyrocatHD...a variety of film.

Perhaps SS reels are less prone to trap bubbles?

 

[canuhead]

nope. steel will have these issues as well. first hand experience. fluids over top of the reels, and tapping it firmly after each agitation cycle help. esp the chemistry levels. more so if using Pyrocat, which seems to froth very easily.

 

[GLS]

I used to get this issue occasionally with Pyrocat-HD even when using 600 mL in a Paterson tank (500 mL is required to just cover the reel). When it happens I assume the minimal agitation regime makes the effect worse (I don't use rotary processing).

 

[Patrick Robert James]

The bubbles only happen on plastic reels.

I always used LFN. Been using it for 25 years since HIE always got air bells without it. The last good bottle I had was the little white one that said "frying time" instead of drying time. The bottle cracked a while back and I got one of the new clear bottles with a red label. I don't know what they did to the stuff, but it is terrible now. The first tank I did with it and Pyrocat mixed in Glycol was unreal. Foamed beyond belief. I guess it was the combination of the LFN and the Glycol. Definitely not the same stuff it used to be. I stopped using it and started getting the bubbles with my JOBO reels. Drives me nuts! I'm glad IPA works. I'll start using that.

This is what the film looked like with the LFN-

 

[Vaughn]

Perhaps SS reels are less prone to trap bubbles?

I think the design of the plastic reels does not help.

 

[Sirius Glass]

The bubbles only happen on plastic reels.

I always used LFN. Been using it for 25 years since HIE always got air bells without it. The last good bottle I had was the little white one that said "frying time" instead of drying time. The bottle cracked a while back and I got one of the new clear bottles with a red label. I don't know what they did to the stuff, but it is terrible now. The first tank I did with it and Pyrocat mixed in Glycol was unreal. Foamed beyond belief. I guess it was the combination of the LFN and the Glycol. Definitely not the same stuff it used to be. I stopped using it and started getting the bubbles with my JOBO reels. Drives me nuts! I'm glad IPA works. I'll start using that.

This is what the film looked like with the LFN-

View attachment 231456

The bubbles only happen on plastic reels.

I disagree based on my experience with HIE and many other films. I got air bubbles with stainless steel reels and plastic reels until I thumped the tank. A linoleum block works better than a sink for this.

However I have never gotten bubbles with plastic tanks on the Jobo processor with or without pre-soaking.

 

[Arklatexian]

Which beer are you adding? Interested reader want to know!
View attachment 231421

Sirius, are you sure that you are not using a dictionary aimed at "Brits"? Sure sounds like it to me. After all, you know what you speak is not: "British". What I speak is not "British" either.............Regards!

 

[Patrick Robert James]

I disagree based on my experience with HIE and many other films. I got air bubbles with stainless steel reels and plastic reels until I thumped the tank. A linoleum block works better than a sink for this.

However I have never gotten bubbles with plastic tanks on the Jobo processor with or without pre-soaking.

The bubbles being talked about in this thread are the edge bubbles that get trapped between the film and the edge of the reel on plastic reels and 120 film. Whacking the tank doesn't displace the ones the OP is talking about for the most part. They just move a little in my experience. I whack the crap out of the tank too. The problem is the bubbles are bigger than the spaces on the reels.

 

[Arklatexian]

Good IPA and other low MW alcohols have no significant effect on emulsions but do reduce bubbles.

PE

PE, years ago there was a Film quick drier, on the market that was an alcohol. Do you know which one. In the shop where I worked, every plastic bottle we had "leaked" through the pores of the plastic leaving a puddle of the alcohol around each bottle. I have not seen such a film drier since.......Regards!

 

[Arklatexian]

I disagree based on my experience with HIE and many other films. I got air bubbles with stainless steel reels and plastic reels until I thumped the tank. A linoleum block works better than a sink for this.

However I have never gotten bubbles with plastic tanks on the Jobo processor with or without pre-soaking.

Could it be that the Jobo has "constant agitation" and the film is "laying" on its side"? Just a thought.........Regards! (or is it "lying on its side? I knew the difference once.)

 

[Sirius Glass]

Could it be that the Jobo has "constant agitation" and the film is "laying" on its side"? Just a thought.........Regards! (or is it "lying on its side? I knew the difference once.)

Could well be both.

 

[canuhead]

Could it be that the Jobo has "constant agitation" and the film is "laying" on its side"? Just a thought.........Regards! (or is it "lying on its side? I knew the difference once.)

Well the film and chemistry are in constant motion so air bubbles don't get a chance to park on the film as it would in regular tanks used for inversions. Perhaps this is one reason why the Formulary (and Sandy King I presume) recommend either tray or rotary processing when using Pyrocat HD.

 

[Photo Engineer]

PE, years ago there was a Film quick drier, on the market that was an alcohol. Do you know which one. In the shop where I worked, every plastic bottle we had "leaked" through the pores of the plastic leaving a puddle of the alcohol around each bottle. I have not seen such a film drier since.......Regards!

There were several such formulas, all of which had one sort of problem or another. Most did work though.

PE

 

[pentaxuser]

So, an update on this issue:


One word of warning to those who may wish to try this however: I have found that mixing IPA and water creates a non-trivial exotherm. My water was initially at 22 C, but upon mixing it 570:30 with the IPA the temperature went up to 24 C,

Glad it worked. I regularly mix water with alcohol. The best alcohol and water mixture I have found is from Speyside in Scotland On a slightly more serious note, this is a new one on me.

It doesn't sound as if there were any other extraneous factors to have caused this so can we assume that it was simply the IPA and water and can anyone explain how this arises? 2C is quite a jump

Thanks

pentaxuser

 

[Vaughn]

Glad it worked. I regularly mix water with alcohol. The best alcohol and water mixture I have found is from Speyside in Scotland...pentaxuser

Rarely, but only if the water is in a frozen state. Hmmm, so that is why the ice melts too fast...

 

[GLS]

It doesn't sound as if there were any other extraneous factors to have caused this so can we assume that it was simply the IPA and water and can anyone explain how this arises? 2C is quite a jump

It is due to a phenomenon called enthalpy of mixing (https://en.wikipedia.org/wiki/Enthalpy_of_mixing).

In layman's terms this simply means a change in the enthalpy (or heat energy) of a system when two substances are mixed together (in this case water and IPA).

I did a quick search and actually found a graph which illustrates this very case (at three different temperatures):

A negative enthalpy change of the system signifies a release of heat energy into the surroundings, and a positive enthalpy change vice versa. You can see from the graph that at lower proportions of IPA (<10%) the enthalpy decreases sharply, and at higher proportions the behaviour inverts. The temperature I used (22 C or 295 K) would give a response intermediate between the purple and blue curves.