Circular and Hazy Stains in Dip-and-Dunk C-41

[vicb]

It sounds to me that this may be your problem. As had been mentioned, you shouldn't have to change the stabilizer tank solution even once a day.

Maybe see how you fare out when you fix the stabilizer tank missing tube and let it replenish at the recommended rate.

Yes, you're right, thank you!

 

[Lachlan Young]

I haven’t really looked into it yet, and I’m not entirely sure how to measure it accurately?

Even a very basic hygrometer will give you enough of the essentials to get a handle on what's going on, and if the DnD machine is new enough, it ought to have sensors telling you what's going on in the drier (the industry standard manual that covers the fundamentals of process machine design has an extensive section on drier design, drying faults and how to prevent them).

Unless you have an impingement (or equivalent) drier on the machine, you generally want to ensure your drying time is really not less than 15 minutes, but if your ambient/ drying unit humidity level is low, the temperature you specified using may be way more than you need to hit that aim (in fact you may need no heat at all if your relative humidity is low), and thus you are potentially drying in spots and shoreline marks etc.

 

[vicb]

Hi everyone,

I’m running a dip & dunk C-41 line and I’m having recurring issues with what appear to be stabilizer drying marks.

Current setup:

• Final rinse tank: approx. 18L distilled/filtered water
• Bellini stabilizer: 180ml added to the18L tank (as per standard dilution)
• Replenishment rate: 200ml per rack
  • Each rack = 3×135 + 2×120
• Chemistry is replenished every cycle
• Water is clean and filtered
• No additional wetting agent added

The stains are clearly coming from the stabilizer stage. They look like typical surfactant drying marks. When I rewash the film, the stains usually disappear, but I’d obviously prefer the film to come out clean on the first run.

I’m wondering:

• Could this be surfactant concentration creep?
• Should I reduce stabilizer concentration slightly?
• Would lowering replenishment from 200ml to 150ml per rack make sense?

Any other ideas I might be missing?

For those running similar 15–20L dip & dunk systems: what stabilizer dilution and replenishment rates are you using?

Appreciate any insight!

Thank you

 

[koraks]

This seems to be a continuation or even repetition of the question you asked before: https://www.photrio.com/forum/threads/circular-and-hazy-stains-in-dip-and-dunk-c-41.217924
If so, would you mind if we merge these threads? I understand the problem is still unresolved, but experiences tells me that the odds of finding a solution do not necessarily increase with opening a new thread on the same issue. What does increase, is the risk of having a redundant discussion in which relevant information ends up difficult to find.

 

[vicb]

This seems to be a continuation or even repetition of the question you asked before: https://www.photrio.com/forum/threads/circular-and-hazy-stains-in-dip-and-dunk-c-41.217924
If so, would you mind if we merge these threads? I understand the problem is still unresolved, but experiences tells me that the odds of finding a solution do not necessarily increase with opening a new thread on the same issue. What does increase, is the risk of having a redundant discussion in which relevant information ends up difficult to find.

Yes, no worries! I apologize!

 

[koraks]

Not a problem at all, I'll merge them together!

 

[vicb]

Not a problem at all, I'll merge them together!

Thank you, I appreciate it!

 

[YoIaMoNwater]

If you're getting spots near frame 17, then I'm assuming that's the top loop on the hanger where bubbles can accumulate and cause marks if not properly agitated. It's possible your delay is too long.

Generally the nitrogen gas burst should be 2" every 10" ( raising the solution level by around an inch ).
Gas should ideally go through a humidifier before feeding the tank.

Stabiliser tank can be tricky to get right. Concentration balance is vital.
You may also look into installing a 'wet trough' in the drying cabinet to add some humidity.

John S

I’m also having issue with Bellini stabiliser from the E6 kit as it leaves dry water marks. I manually process with a Paterson tank and use deionised water for all the chemicals. I’ve tested with the suggested 1:100 dilution (10 mL stock for 1 L) and also 1:200 dilution, and it still leaves residues. Is there a specific dilution that works for you with UK’s hard water? Anyone else with hard water can provide some dilution suggestions?