Recently, it has become clear that it would be helpful for bubble juice mixologists to have some "baselines" that they can use for determining their detergent strengths and the related soap film thickness (via the color profile). It also seems clear that some solid baselines can be used to help us understand the way that our various amendments influence the soap film.
Analyzing, video of bubbles made outside is tricky because it is often hard to get the right lighting conditions to make a proper evaluation and one is subect to variables that can influence one's conclusions.
So, I have been trying to find a setup that would enable me to get consistent results across multiple sessions that will also be easy for others to replicate. So, that we can hopefully get a set of of detergent evaluations from around the world.
The Lonevity Test setup is a useful in that it allows you create bubbles of uniform sizes as well as get a feel for th relative longevity of mixes. I have had a problem in the past of performing the test in such a way as to get a good color profile. After conferring with a few avid photographers and reading a few articles about the lighting of some great bubble photos done by professional photographes, I realized that some version of a lightbox was needed.
Since I was going to be spending time setting up and playing with the lightbox, I figured that I should also do some of the evaluations that were of interest to me.
In this session, I wanted to look at a few things:
- the influence of baking powder on water/detergent mixes in terms of film thickness and longevity
- the influence of guar gum and/or gelatin on soap film thickness
- determining if the lightbox setup would allow us to see same sort of differences in color profile that big bubbles outside (under the right lighting conditions) do
In this session, I took a look at the following solutions:
- 13:1 tap water and Dawn Pro with and without baking powder
- 26:1 tap water and Dawn Pro with and without baking powder
- 26:1 tap water, Dawn Pro, baking powder and guar gum with and without gelatin (which has been recently suggested as a bubble life extender)
It will be left for a future session to compare baking powder to baking soda+citric acid and to citric acid alone (to see if pH is the prime benefit of these additives).
There were not any big surprises in the session. As expected, the bubbles with the 26:1 dilution lasted longer (on the average) than the 13:1 dilution bubbles. The mixes with guar gum lasted noticeably longer than the mixes without. The longest lived bubble had gelatin in it, but, on average, the guar gum+gelatin bubbles had a similar lifespan to the guar bubbles.
There was one small surprise in that the longevity was not strictly a function of the film thickness. The 13:1 no baking powder bubbles had a similar film thickness to the 26:1 with baking powder bubbles and yet the 26:1 + baking powder bubbles had noticeably longer average longevity.
A video showing one representative of each solution. I chose the most representative trial for each solution.
A video showing 3 or 4 trials of each tested solution at once. This video gives you a chance to see some of the variation that will happen even in quite controlled circumstances (at least compared to out in the real world).