First suitably overcast morning since I made the test juices earlier this month. All juice used 1 liter of water, detergent, 5% citric acid solution for pH adjustment (to adjust to pH 7.6) and 9 grams of BLM per liter of water.
The juices were:
- Dawn Pro (2017) at 20:1. Tap water juice.
- Dawn Pro (2017) at 20:1. Distilled water.
- Dawn Ultra 3x at 20:1. Tap water
- Dawn Ultra 3x at 25:1. Tap water.
Conditions. Temperature 64F and humidity 76%. Time of day 8 am (PDT). Mild breeze.
Each solution had its own loop: 32" top-string of Secureline 3/16" diamond braid cord.
All juices worked equally well. Many tubes in the 30-40 foot range -- though the breeze was slow enough that long tubes split into individual bubbles. Several tubes would have exceeded 40 feet by quite a bit if the bubbles hadn't split off.
Color Profile Quick Take. Ultra 3x at 20:1 was similar-ish to Dawn Pro at 16:1 (though perhaps not as thin-filmed). Ultra 3x at 25:1 was quite similar to Dawn Pro at 20:1 though I need to review the videos again.
Still of a typical tube from the session. All solutions produced many tubes of this length.
Dawn Pro at 20:1 - Tube
Dawn Ultra 3x at 20:1 - Tube
Color Profile Comparisons
One of the session's goals was to compare color profiles of Ultra 3x to typical Dawn Pro solutions as Ultra 3x has higher effective surfactancy and I am trying to figure out the equivalence. The images below are typical bubbles. These profiles dominated. "Typical" is the color profile of tubes from about 10 to 20 or so feet. The "stretched" column is the profile of the thinnest films achieved -- which were tubes approaching 40 feet long with this setup. As a bubble exhausts the wick's capacity the resulting film gets thinner and thinner. See conclusions section below.
Dawn Ultra 3x clearly has higher surfactancy than Dawn Pro Manual Pot and Pan. Dawn Ultra 3x also requires more acid than Dawn Pro to achieve a similar pH. More about the amount of citric acid needed to adjust these detergents found on PH Adjusters and Water Conditioners.
Based on this session and another, my current feeling is that Dawn Ultra 3x at 25:1 achieves a somewhat thinner film than Dawn Pro at 20:1 and that Dawn Ultra 3x at 20:1 is similar to Dawn Pro at a little higher than 16:1. All comparisons based on pH-adjusted juice where pH was dropped to about 7.6 with 5% citric acid solution.