[Ananova]

I'm not a chemist, but I have an interest in restoring old lava lamps and being able to make lava lamps that flow like the older ones did in the 90's. In 2003 they moved manufacturing to China and have never been the same.

The basic breakdown of how a lava lamp works is the lightbulb provides heat that causes the wax to expand and become less dense than water which makes it rise until it contracts again. A surfactant is used to prevent the wax from sticking to the glass and to reduce surface tension to cause the wax to stretch instead of form nothing but round blobs. As the wax falls a metal spring (coil) breaks the surface tension and allows the wax to rejoin the main blob at the bottom.

I have my own liquid formula that I have been working on. This formula recreates the desired properties in the lamp, but I know it is not the same used in the original formula.

66.9% Water
24% Propylene Glycol
6% Glycerol
3% Sodium Lauryl Sulfate
0.01% Triton X-100 (1ML) - polyethylene glycol tert-octylphenol ethoxylate
*Final density has to be adjusted for variances of wax density by addition of water or glycerol.

The lamp seems to more or less flow like it should, but I can't help but wonder about about this formula breakdown I came across. The wax is actually really straight forward. The mystery for me is why they are using different chemicals and if it even really matters.

Here is the formula breakdown.
https://images.homedepot-static.com/catalog/pdfImages/89/89937a2d-c18f-4fc0-ac73-239f481c8a0b.pdf

1. What is the difference between sodium lauryl sulfate and magnesium lauryl sulfate? Why would one be used over the other? Common hobbyist formulas use sodium lauryl sulfate because it is easy to purchase. Is that an adequate substitute?
2. Is the Tetrasodium Ethylenediaminetetraacetate added to prevent rusting of the metal coil in the bottom of the bottle?
3. Is the hydrochloric acid added to adjust the PH so the Tetrasodium Ethylenediaminetetraacetate is at an appropriate PH range to function as a corrosion preventative?
4. I am assuming there are 3 surfactants. Magnesium lauryl sulfate, polyethylene glycol tert-octylphenol ethoxylate, and alcohols C10-C12 Ethoxylated. Why 3 and not just 1?
5. My assumption is polyethylene glycol is added to increase density and reduce thermal expansion of the water so the density remains stable at higher temperatures, but I could be wrong. Again common hobbyist recipes differ and use propylene glycol instead. What is the difference between the two?
6. Methyl Paraben. I assume this is just for antifungal properties?

[Ananova]

I guess I underestimated the complexity of the wax because once I dove into it I realized it was a beast of its own to figure out. The SDS sheets are misleading at best. Anyways in case anyone ever comes across this and takes interest I've been extensively documenting my work. I'll keep smashing things together and hoping they work, but it would be nice if I had some actual expertise interested in this project.

https://docs.google.com/spreadsheets/d/1KVck9CWQj3tfQXR5C5eE-CFjwad156RhBMYnCZehBfw/edit#gid=950924701
https://docs.google.com/document/d/1nZCHLV5-GayA83oWkdMKBTB3u1zf_FPRjVU-x8WMxyQ/edit#