How can I prevent fresh blix from popping the Patterson tank lid?

[Certain Exposures]

I experience this issue with fresh chemistry, regardless of the C-41 kit I've tried.

I immediately 'burp' the Patterson tank lid by squeezing out as much air as possible when I fill it with blix. However, the gases cause the lid to rise as the tank spins, and I use a processor that holds the tank on its side. The gas forces me to disrupt the developing process to burp several times, and it causes a bit of leaking.

How can I avoid this issue without switching to a new tank style or changing my C-41 kit? I know ECN-2 does not do this. I prefer the simplicity of the two-step C-41 process.

I have no desire to switch to a Jobo tank or process because that setup is too large and expensive.

Is there an 'easy' win here? I wish the Patterson tank had a lid with more room to expand. That would be an improvement.

 

[koraks]

Use a stop bath (e.g. 1% acetic acid) between developer and blix. The tank will still need to be burped and the lid may pop, but the only thing lost is your virtually free stop bath. Then the blix won't pop the lid anymore.

I know ECN-2 does not do this

Yeah it does.

 

[Certain Exposures]

Use a stop bath (e.g. 1% acetic acid) between developer and blix. The tank will still need to be burped and the lid may pop, but the only thing lost is your virtually free stop bath. Then the blix won't pop the lid anymore.


Yeah it does.

Do you use distilled water for your stop bath or tap water? Have you noticed uneven development or 'splotchiness' on your negatives when you use stop bath during C-41 home development?

At one point, I tried a quick tap water bath between the developer and blix steps. I stopped (no pun intended) because I noticed uneven development/splotchiness when I did that. I suspected that the tap water in my area might contain impurities. I use distilled water for my developer and blix steps. I could try using distilled water to mix the stop bath.

Yeah it does

I don't recall my QWD Lab ECN-2 kits causing a similar issue with the tank lid popping. Maybe I have a rosy memory.

 

[koraks]

Do you use distilled water for your stop bath or tap water?

Doesn't matter; tap is fine. You need to mix a little acid into it; see my post above.

Have you noticed uneven development or 'splotchiness' on your negatives when you use stop bath during C-41 home development?

No; in fact, part of a stop bath's point is to prevent these issues.

At one point, I tried a quick tap water bath between the developer and blix steps.

Plain water is not a stop bath; there needs to be an acid in it. I suggested 1% acetic acid above.

I don't recall my QWD Lab ECN-2 kits causing a similar issue with the tank lid popping.

Whether the lid pops depends mostly on how much liquid you put into the tank, whether you depress the central part of the lid (so it can pop out, although this is not a 100% protection against spillage) and how well the lid fits in the first place. Whether or not the lid pops off is a bit of a random thing for these reasons.
Either way, a typical ECN2 process as people generally run it at home, involving often a ferricyanide bleach, should most definitely include an acidic stop bath after the developer (which will cause generation of CO2 gas which is what makes the lid pop), followed by a sulfite clearing bath and then the ferricyanide bleach.

 

[pentaxuser]

If it is any help and it may not be, based on what you have stated to koraks after his advice. I too only ever experienced a problem with the lid popping with stop bath and then only because initially I was not burbing the lid. I can't recall ever experiencing a problem with blix once I had burped the tank lid when using stop

In my case it was Jobo tanks on a Jobo processor so like you the tank was on its side continuously rotating and that I am sure added to the problem of popping

Frankly it might be just as easy to use the stop by inverting where it will still be inclined to pop but maybe less so because the tank is upright and if it does there is no loss of stop. Then use the blix with the tank rotating once agaín.

Worth a try but it's your decision

pentaxuser